ABCMdb

ABCD1 p.Arg617His

ClinVar:	c.1849C>T , p.Arg617Cys D , Pathogenic c.1850G>A , p.Arg617His D , Pathogenic
Predicted by SNAP2:	A: D (95%), C: D (95%), D: D (95%), E: D (95%), F: D (95%), G: D (95%), H: D (95%), I: D (95%), K: D (95%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: D, K: N, L: D, M: D, N: D, P: D, Q: D, S: D, T: D, V: D, W: D, Y: D,

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[hide] ABCD1 mutations and the X-linked adrenoleukodystro... Hum Mutat. 2001 Dec;18(6):499-515. Kemp S, Pujol A, Waterham HR, van Geel BM, Boehm CD, Raymond GV, Cutting GR, Wanders RJ, Moser HW
ABCD1 mutations and the X-linked adrenoleukodystrophy mutation database: role in diagnosis and clinical correlations.
Hum Mutat. 2001 Dec;18(6):499-515., [PMID:11748843]

Abstract [show]
X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ABCD1 gene, which encodes a peroxisomal ABC half-transporter (ALDP) involved in the import of very long-chain fatty acids (VLCFA) into the peroxisome. The disease is characterized by a striking and unpredictable variation in phenotypic expression. Phenotypes include the rapidly progressive childhood cerebral form (CCALD), the milder adult form, adrenomyeloneuropathy (AMN), and variants without neurologic involvement. There is no apparent correlation between genotype and phenotype. In males, unambiguous diagnosis can be achieved by demonstration of elevated levels of VLCFA in plasma. In 15 to 20% of obligate heterozygotes, however, test results are false-negative. Therefore, mutation analysis is the only reliable method for the identification of heterozygotes. Since most X-ALD kindreds have a unique mutation, a great number of mutations have been identified in the ABCD1 gene in the last seven years. In order to catalog and facilitate the analysis of these mutations, we have established a mutation database for X-ALD ( http://www.x-ald.nl). In this review we report a detailed analysis of all 406 X-ALD mutations currently included in the database. Also, we present 47 novel mutations. In addition, we review the various X-ALD phenotypes, the different diagnostic tools, and the need for extended family screening for the identification of new patients.

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174 P560S 7 1678C>T n.d. # P560L 7 1679C>T Reduced P560L 7 1679C>T Reduced fs I588 7 1765delC n.d. # R591P 7 1772G>C Absent S606L 8 1817C>T Present E609K 8 1825G>A Absent E609K 8 1825G>A Absent R617C 8 1849C>T Absent R617H 8 1850G>A Absent R617H 8 1850G>A Absent A626T 9 1876G>A Absent A626T 9 1876G>A Absent A626D 9 1877C>A n.d. # E630G 9 1889A>G n.d. # C631Y 9 1892G>A n.d. # T632I 9 1895C>T n.d. # V635M 9 1903G>A n.d. # L654P 9 1961T>C Absent # R660W 9 1978C>T Absent fs L663 9 1988insT n.d. # fs L663 IVS 9 IVS9+1g>a n.d. # fs L663 IVS 9 IVS9-1g>a n.d. # H667D 10 1999C>G Absent # T668I 10 2003C>T Absent # T693M 10 2078C>T Present # exon1-5del 1-5 n.d. # The 47 mutations marked with a # are novel unique mutations reported for the first time in this paper. Login to comment

[hide] Komrower Lecture. Adrenoleukodystrophy: natural hi... J Inherit Metab Dis. 1995;18(4):435-47. Moser HW
Komrower Lecture. Adrenoleukodystrophy: natural history, treatment and outcome.
J Inherit Metab Dis. 1995;18(4):435-47., [PMID:7494402]

Abstract [show]
Our laboratory has identified nearly 2000 patients with X-linked adrenoleukodystrophy (ALD) and conducted therapeutic trials in groups of patients who represent the major phenotypes. We report recent results of dietary therapy with a mixture of glyceryl trioleate and glyceryl trierucate oil, also referred to as Lorenzo's Oil, in the asymptomatic and childhood cerebral phenotypes. Fifty-three patients started this therapy at a mean age of 7.5 years at a time when they were free of neurological symptoms. Although analysis of data is hampered by the lack of a concurrent control group, follow-up studies after 39 months of therapy suggest that subsequent neurological involvement was less frequent and less severe than anticipated from historical controls. Retrospective analysis of the effect of the oil in patients with the severe childhood cerebral phenotype indicates that there was a slight but statistically significant slowing of clinical progression and delay of death.

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29 Mutation Predicted consequence Phenotype a 1 310 C -4 T R104C AMN 2 420 G -4 A A140T Cer 3 454 C -4 T R152C Cer 4 545 G -4 C R182P Addis 5 692 G -4 C Addis 693-4 del GG Frameshift at AA 231 6 770 G -4 T G277W Cer 7 1166 G -4 A R389H AMN 8 I224 G -4 A Spl mutation at AA 408 AMN 9 1389 G --+ A R464 stop AMN 10 1411 ins A Frameshift at AA 470 AMN 11 1412-3 del AA Frameshift at AA 470 Cer 12 1415-6 del AG Frameshift at AA 472 Cer 13 1415-6 del AG Frarneshift at AA 472 Cer 14 1415-6 del AG Frameshift at AA 472 Addis 15 1415-6 del AG Frameshift at AA 472 AMN 16 t415-6 del AG Frameshift at AA 472 AMN 17 1415-6 del AG Frameshift at AA 472 Cer 18 1534 G -4 A G512S Cer 19 1698 T -4 A M567K AMN 20 t817 C -4 T $604F Addis 1548 G -4 A L516L 21 1850 G -+ A R617H AMN 22 1978 G -4 A R660W AMN ~Cer=childhoodcerebralALD; Addis=Addisondisease the multiple binding sites on bovine albumin for shorter-chain fatty acids, there is only a single binding site for C26:0. Login to comment

[hide] Conservation of targeting but divergence in functi... Biochem J. 2011 Jun 15;436(3):547-57. Zhang X, De Marcos Lousa C, Schutte-Lensink N, Ofman R, Wanders RJ, Baldwin SA, Baker A, Kemp S, Theodoulou FL
Conservation of targeting but divergence in function and quality control of peroxisomal ABC transporters: an analysis using cross-kingdom expression.
Biochem J. 2011 Jun 15;436(3):547-57., [PMID:21476988]

Abstract [show]
ABC (ATP-binding cassette) subfamily D transporters are found in all eukaryotic kingdoms and are known to play essential roles in mammals and plants; however, their number, organization and physiological contexts differ. Via cross-kingdom expression experiments, we have explored the conservation of targeting, protein stability and function between mammalian and plant ABCD transporters. When expressed in tobacco epidermal cells, the mammalian ABCD proteins ALDP (adrenoleukodystrophy protein), ALDR (adrenoleukodystrophy-related protein) and PMP70 (70 kDa peroxisomal membrane protein) targeted faithfully to peroxisomes and P70R (PMP70-related protein) targeted to the ER (endoplasmic reticulum), as in the native host. The Arabidopsis thaliana peroxin AtPex19_1 interacted with human peroxisomal ABC transporters both in vivo and in vitro, providing an explanation for the fidelity of targeting. The fate of X-linked adrenoleukodystrophy disease-related mutants differed between fibroblasts and plant cells. In fibroblasts, levels of ALDP in some 'protein-absent' mutants were increased by low-temperature culture, in some cases restoring function. In contrast, all mutant ALDP proteins examined were stable and correctly targeted in plant cells, regardless of their fate in fibroblasts. ALDR complemented the seed germination defect of the Arabidopsis cts-1 mutant which lacks the peroxisomal ABCD transporter CTS (Comatose), but neither ALDR nor ALDP was able to rescue the defect in fatty acid beta-oxidation in establishing seedlings. Taken together, our results indicate that the mechanism for trafficking of peroxisomal membrane proteins is shared between plants and mammals, but suggest differences in the sensing and turnover of mutant ABC transporter proteins and differences in substrate specificity and/or function.

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181 These included relatively common mutants which are unstable in fibroblasts, but which can be rescued by the application of proteasome inhibitors (p.Ser606Leu, p.Arg617His and p.His667Asp), the p.Arg104Cys mutant in which degradation of ALDP cannot be prevented by proteasome inhibitors and the p.Tyr174Cys mutant which is Table 2 X-ALD mutants used for analysis of targeting in tobacco cells The occurrence is the number of documented patients bearing the mutation; source: X-ALD database (http://www.x-ald.nl). Login to comment
182 These included relatively common mutants which are unstable in fibroblasts, but which can be rescued by the application of proteasome inhibitors (p.Ser606Leu, p.Arg617His and p.His667Asp), the p.Arg104Cys mutant in which degradation of ALDP cannot be prevented by proteasome inhibitors and the p.Tyr174Cys mutant which is c The Authors Journal compilation c Table 2 X-ALD mutants used for analysis of targeting in tobacco cells The occurrence is the number of documented patients bearing the mutation; source: X-ALD database (http://www.x-ald.nl). Login to comment

[hide] X-linked adrenoleukodystrophy: diagnostic and foll... J Hum Genet. 2011 Feb;56(2):106-9. Epub 2010 Nov 11. Shimozawa N, Honda A, Kajiwara N, Kozawa S, Nagase T, Takemoto Y, Suzuki Y
X-linked adrenoleukodystrophy: diagnostic and follow-up system in Japan.
J Hum Genet. 2011 Feb;56(2):106-9. Epub 2010 Nov 11., [PMID:21068741]

Abstract [show]
X-linked adrenoleukodystrophy (ALD) is an intractable neurodegenerative disease associated with the accumulation of very long-chain saturated fatty acids (VLCFA) in tissues and body fluids. We have established a Japanese referral center for the diagnosis of ALD, using VLCFA measurements and mutation analysis of the ABCD1 gene, and have identified 60 kinds of mutations in 69 Japanese ALD families, which included 38 missense mutations, 6 nonsense mutations, 8 frame-shift mutations, 3 amino acid deletions, 2 exon-skip mutations and 3 large deletions. A total of 24 kinds of mutations (40%) were identified only in Japanese patients by referring to the current worldwide ALD mutation database. There was no clear correlation between these mutations and phenotypes of 81 male patients in these 69 families. About 12% of the individuals with ALD had de novo mutations by mutation analysis in the male probands and their mothers, which should be helpful data for genetic counseling. The only effective therapy for the cerebral form of ALD should be hematopoietic stem cell transplantation at the early stages of the cerebral symptoms, therefore, we performed presymptomatic diagnosis of ALD by extended familial screening of the probands with careful genetic counseling, and established a long follow-up system for these patients to prevent the progression of brain involvement and to monitor the adrenocortical insufficiency. Further elucidation of pathology in ALD, especially concerning the mechanisms of the onset of brain involvement, is expected.

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21 Although most probands with ALD identified by us had a unique gene mutation, 6 missense mutations (p.Gly266Arg, p.Arg401Gln, p.Gly512Ser, p.Ser514Ile, p.Arg617His and p.Arg660Trp) and 1 frame-shift mutation (p.Gln472fs) were detected in two or three families (* in Figure 2). Login to comment

[hide] Adrenoleukodystrophy: subcellular localization and... J Neurochem. 2007 Jun;101(6):1632-43. Takahashi N, Morita M, Maeda T, Harayama Y, Shimozawa N, Suzuki Y, Furuya H, Sato R, Kashiwayama Y, Imanaka T
Adrenoleukodystrophy: subcellular localization and degradation of adrenoleukodystrophy protein (ALDP/ABCD1) with naturally occurring missense mutations.
J Neurochem. 2007 Jun;101(6):1632-43., [PMID:17542813]

Abstract [show]
Mutation in the X-chromosomal adrenoleukodystrophy gene (ALD; ABCD1) leads to X-linked adrenoleukodystrophy (X-ALD), a severe neurodegenerative disorder. The encoded adrenoleukodystrophy protein (ALDP/ABCD1) is a half-size peroxisomal ATP-binding cassette protein of 745 amino acids in humans. In this study, we chose nine arbitrary mutant human ALDP forms (R104C, G116R, Y174C, S342P, Q544R, S606P, S606L, R617H, and H667D) with naturally occurring missense mutations and examined the intracellular behavior. When expressed in X-ALD fibroblasts lacking ALDP, the expression level of mutant His-ALDPs (S606L, R617H, and H667D) was lower than that of wild type and other mutant ALDPs. Furthermore, mutant ALDP-green fluorescence proteins (S606L and H667D) stably expressed in CHO cells were not detected due to rapid degradation. Interestingly, the wild type ALDP co-expressed in these cells also disappeared. In the case of X-ALD fibroblasts from an ALD patient (R617H), the mutant ALDP was not detected in the cells, but appeared upon incubation with a proteasome inhibitor. When CHO cells expressing mutant ALDP-green fluorescence protein (H667D) were cultured in the presence of a proteasome inhibitor, both the mutant and wild type ALDP reappeared. In addition, mutant His-ALDP (Y174C), which has a mutation between transmembrane domain 2 and 3, did not exhibit peroxisomal localization by immunofluorescense study. These results suggest that mutant ALDPs, which have a mutation in the COOH-terminal half of ALDP, including S606L, R617H, and H667D, were degraded by proteasomes after dimerization. Further, the region between transmembrane domain 2 and 3 is important for the targeting of ALDP to the peroxisome.

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2 In this study, we chose nine arbitrary mutant human ALDP forms (R104C, G116R, Y174C, S342P, Q544R, S606P, S606L, R617H, and H667D) with naturally occurring missense mutations and examined the intracellular behavior. Login to comment
3 When expressed in X-ALD fibroblasts lacking ALDP, the expression level of mutant His-ALDPs (S606L, R617H, and H667D) was lower than that of wild type and other mutant ALDPs. Login to comment
6 In the case of X-ALD fibroblasts from an ALD patient (R617H), the mutant ALDP was not detected in the cells, but appeared upon incubation with a proteasome inhibitor. Login to comment
9 These results suggest that mutant ALDPs, which have a mutation in the COOH-terminal half of ALDP, including S606L, R617H, and H667D, were degraded by proteasomes after dimerization. Login to comment
35 We found that mutant ALDPs with the missense mutations in the G116R S342P Q544R R617H H667D Y174C NH2 COOH C sequence Cytosol Membrane Matrix Walker A Walker B S606P, S606L R104C Fig. 1 A putative secondary structure of adrenoleukodystrophy protein. Login to comment
71 CHO-K1 cells (5 · 105 cells) were cultured in Ham`s F-12 medium with 10% FBS, 70 lg/mL of penicillin, and 140 lg/mL of streptomycin and transfected with 5 lg of pMAM2/ Table 1 Oligonucleotide primer sequences used for the generation of mutant ALDP constructs Construct name Forward primer (5' to 3') (top) R104C GCCTTGGTGAGCTGCACCTTCCTGTCG G116R GCCCGCCTGGACAGAAGGCTGGCC Y174C GCCTACCGCCTCTGCTCCTCCCAG S342P TGGAGCGCCCCGGGCCTGCTCATG Q544R GCATGTTCTACATCCCGCGGAGGCCCTACATGTC S606P AAGGACGTCCTGCCGGGTGGCGAGAAG S606L AAGGACGTCCTGTTGGGTGGCGAGAAG R617H GCAGAGAATCGGCATGGCCCACATGTTCTACCACAGGC H667D TCCCTGTGGAAATACGACACACACTTGCTA The underlined letters indicate the single base mutation leading to an amino acid replacement. Login to comment
120 However, the ratios of certain His-ALDPs (S606L, R617H, and H667D) were significantly lower than those of wild type His-ALDP and other mutant His-ALDPs. Login to comment
123 Therefore, we focused our attention on mutant ALDP (S606H, R617H, and H667D) and examined the expression level with co-expression of GFP. Login to comment
125 Taken together, it appears His-ALDP (S606L, R617H, and H667D) might be degraded after translation. Login to comment
129 Immunofluorescent dots of His-ALDP (R617H) were scarcely detected in the cells because of the low level of expression. Login to comment
150 The fragments were not extractable with 0.1 mol/L sodium carbonate, indicating (a) (c) (b) (d) 400 140 120 100 Expressionratio(%) 80 60 40 His-ALDP R104C G116R Y174C S342P Q544R S606P S606L R617H H667D Catalase 20 0 100 Expressionratio(%) 80 60 40 20 0 350 300 250 200 150 pmol/h/mgprotein 100 50 0 Normal (139T) X-ALD (163T) M ock M ock W ild W ild N one S606L His-ALDP GFP Catalase R 617H H 667D R 104CG 116RY174C S342PQ 544RS606PS606LR 617HH 667D M ock W ildR 104CG 116RY174CS342PQ 544RS606PS606LR 617HH 667D Fig. 3 Expression of wild type and mutant His-adrenoleukodystrophy proteins (ALDPs) in X-linked adrenoleukodystrophy (X-ALD) fibroblasts (163T). Login to comment
159 (c) Co-expression of wild or mutant His-ALDP (S606L, R617H, or H667D) with green fluorescence proteins (GFP). Login to comment
169 Effect of proteasome inhibitors on mutant ALDP The transient and stable expression experiments of mutant ALDPs suggest that mutant ALDPs such as S606L, R617H, H667D, and R104C are degraded by proteases. Login to comment
187 To confirm that endogenous mutant ALDP is also degraded by proteasomes, we analyzed the effect of proteasomes inhibitors on the stability of mutant ALDP (R617H) (Imamura et al. 1997) in X-ALD fibroblasts. Login to comment
189 As shown in Fig. 7, a band corresponding to ALDP was not detected in the X-ALD fibroblasts (R617H) under the conditions where ALDP was detected in normal fibroblasts and X-ALD fibroblasts (Q544R). Login to comment
190 However, in the presence of MG132, immunoreactive bands corresponding to ALDP appeared in the X-ALD fibroblasts (R617H). Login to comment
191 These results suggest that missense mutations, including R617H and H667D, were also degraded by proteasomes. Login to comment
206 Q544R R617H MG132 Mutant ALDP Catalase -- + Fig. 7 Immunoblot analysis of endogenous mutant adrenoleukodystrophy proteins (ALDPs) (Q544R and R617H) incubated with or without MG132. Login to comment
207 The fibroblasts were incubated with 10 lmol/L MG132 for 20 h. Cell homogenates (100 lg of protein) from the X-linked adrenoleukodystrophy fibroblasts with mutation of ALDP (Q544R) and X-linked adrenoleukodystrophy fibroblasts with mutation of ALDP (R617H) were subjected to immunoblot analysis with anti-ALDP antibody or anti-catalase antibody. Login to comment
218 R617H and H667D are located in the Walker B region and in the COOH-terminal region, respectively (Fig. 1). Login to comment
220 First, we found for the first time that mutant ALDPs (R617H and H667D) were degraded by proteasomes based on the following evidence: (i) The expression levels of these mutant His-ALDPs were relatively low in X-ALD fibroblasts in terms of transient expression (Figs 3b and c, and Table 2). Login to comment
222 (iii) ALDP-GFP (H667D) in the CHO cells and endogenous ALDP (R617H) in X-ALD fibroblasts were detectable by immunoblotting after treatment with lactacystin or MG132 (Figs 5a and 7). Login to comment
229 Recently Lie et al. investigated the dimerization of the COOH-terminal half of ALDP by a yeast two-hybrid assay and found that it could dimerize Table 2 Expression and localization of missense ALDPs Mutant ALDP Transient Stable Expressiona Localizationb b-Oxidationc Expressiona Localizationb Wild +++ Px + ++ Px R104Cd , G116R, S342P, Q544R, S606P +++ Px ) ++ Px Y174C +++ mis ) + mis S606L ++ Px ) ) ) R617H, H667D + ) ) ) ) Wild and mutant His-ALDPs or ALDP-GFPs were transiently expressed in X-ALD fibroblasts or stably expressed in CHO cells, respectively. Login to comment
239 Therefore, mutant ALDP (R617H and H667D) might be misfolded on the peroxisomal membranes and unable to interact correctly with each other or with wild type ALDP and are recruited to proteasomes for degradation. Login to comment
257 Although we did not show any effects of E-64d on the mutant ALDP (R617H and H667D) stability, the possibility cannot be ruled out that other proteases are also involved in the degradation of some of the mutant ALDPs. Login to comment
271 In this study, we found that mutant ALDP (S606L, R617H, and H667D) was degraded by proteasomes together with wild type ALDP. Login to comment

[hide] Variability of endocrinological dysfunction in 55 ... Eur J Endocrinol. 1997 Jul;137(1):40-7. Korenke GC, Roth C, Krasemann E, Hufner M, Hunneman DH, Hanefeld F
Variability of endocrinological dysfunction in 55 patients with X-linked adrenoleucodystrophy: clinical, laboratory and genetic findings.
Eur J Endocrinol. 1997 Jul;137(1):40-7., [PMID:9242200]

Abstract [show]
X-linked adrenoleucodystrophy (ALD) has been shown to be one of the most frequent causes of Addison's disease in men. It is characterized by an impaired peroxisomal beta-oxidation of very long chain fatty acids and is associated with mutations of the ALD gene resulting in a defective peroxisomal membrane transport protein. There is a striking variability of endocrinological and neurological symptoms in patients with ALD, with no clearly evident correlation between mutations of the ALD gene and the different neurological phenotypes. No data on endocrinological symptoms and the ALD genotype have been published so far. We report endocrinological, clinical, laboratory and molecular genetic data from 55 patients with ALD from 34 families. Endocrinological symptoms of adrenal insufficiency were observed in 33 patients, 20 of whom showed additional neurological symptoms of cerebral ALD or adrenomyeloneuropathy. Isolated neurological symptoms were seen in 12 patients; in nine patients there were neither endocrinological nor neurological symptoms. Mutations of the ALD gene (n = 28) were detected in 50 patients (including nine sets of brothers) from 32 families. No correlation was found between the ALD gene mutation and endocrinological dysfunction. However, we found that all sets of brothers were concordant for the endocrinological phenotype (cortisol synthesis was reduced in two sets and normal in seven sets), whereas four sets showed a discordant neurological phenotype. As yet unknown hereditary factors other than mutations within the ALD gene may interfere with the endocrinological phenotype more strongly than with the neurological phenotype of ALD.

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120 Sixteen of these mutations have been published before (11, 21); the remaining 12 mutations comprise nine missense mutations (A141T, Y281H, R389H, G512S, P543L, R554H, Y559H, R617H, R679R), two frame-shift mutations (del 740, del 2132) and one splice site mutation (ins 8 bp 2252). Login to comment

[hide] X-linked adrenoleukodystrophy: ABCD1 de novo mutat... Mol Genet Metab. 2011 Sep-Oct;104(1-2):160-6. Epub 2011 Jun 22. Wang Y, Busin R, Reeves C, Bezman L, Raymond G, Toomer CJ, Watkins PA, Snowden A, Moser A, Naidu S, Bibat G, Hewson S, Tam K, Clarke JT, Charnas L, Stetten G, Karczeski B, Cutting G, Steinberg S
X-linked adrenoleukodystrophy: ABCD1 de novo mutations and mosaicism.
Mol Genet Metab. 2011 Sep-Oct;104(1-2):160-6. Epub 2011 Jun 22., [PMID:21700483]

Abstract [show]
X-linked adrenoleukodystrophy (X-ALD) is a progressive peroxisomal disorder affecting adrenal glands, testes and myelin stability that is caused by mutations in the ABCD1 (NM_000033) gene. Males with X-ALD may be diagnosed by the demonstration of elevated very long chain fatty acid (VLCFA) levels in plasma. In contrast, only 80% of female carriers have elevated plasma VLCFA; therefore targeted mutation analysis is the most effective means for carrier detection. Amongst 489 X-ALD families tested at Kennedy Krieger Institute, we identified 20 cases in which the ABCD1 mutation was de novo in the index case, indicating that the mutation arose in the maternal germ line and supporting a new mutation rate of at least 4.1% for this group. In addition, we identified 10 cases in which a de novo mutation arose in the mother or the grandmother of the index case. In two of these cases studies indicated that the mothers were low level gonosomal mosaics. In a third case biochemical, molecular and pedigree analysis indicated the mother was a gonadal mosaic. To the best of our knowledge mosaicism has not been previously reported in X-ALD. In addition, we identified one pedigree in which the maternal grandfather was mosaic for the familial ABCD1 mutation. Less than 1% of our patient population had evidence of gonadal or gonosomal mosaicism, suggesting it is a rare occurrence for this gene and its associated disorders. However, the residual maternal risk for having additional ovum carrying the mutant allele identified in an index case that appears to have a de novo mutation is at least 13%.

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90 Previously reported (Yes/No) Number of pedigrees reporteda CpG (Yes/No) 25 c.124delC ND No 1 N/A 5 c.279_280ins12bp (p.Leu93_Leu94insGluThrGlyLeu) ND No 1 No 6 c.410G>A (p.Trp137X) ND No 1 No 7 c.412_414delCTC (p.Leu139del) ND Yes 2 No 26 c.476del24 ND No 1 N/A 4 c.593C>G (p.Thr198Met) N/A No 1 Yes 8 c.695_696insG (p.Ala233fsX67) ND No 1 Yes 2 c.725G>A (p.Trp242X) Gonosomal No 1 No c.796G>A (p.Gly266Arg) ND Yes 23 Yes 27 c.797G>A (p.Gly266Gln) ND No 1 No 12 c.944C>A (p.Ser315X) ND No 1 Yes 13 c.1201C>T (p.Arg401Trp) ND Yes 12 Yes 14 c.1225-2A>G (splice defect) ND No 1 No 15 c.1390C>T (p.Arg464X) ND Yes 11 Yes 16 c.1553G>A (p.Arg518 Gln) ND Yes 20 Yes 17 c.1567C>T (p.Leu523Phe) ND No 1 No 18 c.1609C>T (p.Gln537X) ND No 1 No 28 c.1619T>G (p.Phe540Cys) ND No 1 No 19 c.1679C>T (p.Pro560Leu) ND Yes 20 Yes 29 c.1679C>T (p.Pro560Leu) ND Yes 20 Yes 20 exon3 to exon10 deletion ND Yesb 9 N/A 30 c.1781-1G>A ND No 1 No 21 c.1816T>C (p.Ser606Pro) ND Yes 3 No 31 c.1850G>A (p.Arg617His) ND Yes 20 Yes 22 c.1876G>A (p.Ala626Thr) ND Yes 10 Yes 23 c.1894A>C (p.Thr632Pro) ND No 2 No 1 c.1899C>A (p.Ser633Arg) Gonosomal Yes 2 Yes 24 c.1918 G>A (p.Glu640Lys) ND No 2 No 3 c.2030G>A (p.Gly677Asp) Gonadal No 1 Yes de novo mutation in male index case with childhood cerebral X-ALD;somatic and/or gonadal mosaicisim; de novo mutationND = none detected; N/A = not applicable; Color codes: in female carrier. Login to comment

[hide] Altered expression of ALDP in X-linked adrenoleuko... Am J Hum Genet. 1995 Aug;57(2):292-301. Watkins PA, Gould SJ, Smith MA, Braiterman LT, Wei HM, Kok F, Moser AB, Moser HW, Smith KD
Altered expression of ALDP in X-linked adrenoleukodystrophy.
Am J Hum Genet. 1995 Aug;57(2):292-301., [PMID:7668254]

Abstract [show]
X-linked adrenoleukodystrophy (ALD) is a neurodegenerative disorder with variable phenotypic expression that is characterized by elevated plasma and tissue levels of very long-chain fatty acids. However, the product of the gene defective in ALD (ALDP) is a membrane transporter of the ATP-binding cassette family of proteins and is not related to enzymes known to activate or oxidize fatty acids. We generated an antibody that specifically recognizes the C-terminal 18 amino acids of ALDP and can detect ALDP by indirect immunofluorescence. To better understand the mechanism by which mutations in ALDP lead to disease, we used this antibody to examine the subcellular distribution and relative abundance of ALDP in skin fibroblasts from normal individuals and ALD patients. Punctate immunoreactive material typical of fibroblast peroxisomes was observed in cells from seven normal controls and eight non-ALD patients. Of 35 ALD patients tested, 17 had the childhood-onset cerebral form of the disease, 13 had the milder adult phenotype adrenomyeloneuropathy, 3 had adrenal insufficiency only, and 2 were affected fetuses. More than two-thirds (69%) of all patients studied showed no punctate immunoreactive material. There was no correlation between the immunofluorescence pattern and clinical phenotype. We determined the mutation in the ALD gene in 15 of these patients. Patients with either a deletion or frameshift mutation lacked ALDP immunoreactivity, as expected. Four of 11 patients with missense mutations were also immunonegative, indicating that these mutations affected the stability or localization of ALDP. In the seven immunopositive patients with missense mutations, correlation of the location and nature of the amino acid substitution may provide new insights into the function of this peroxisomal membrane protein. Furthermore, the study of female relatives of immunonegative ALD probands may aid in the assessment of heterozygote status.

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176 In 11 patients, missense mutations that occurred throughout the protein were found: within the transmembrane domains (patients 1, 3, and 4), within the ATP-binding domain (patients 8-12), and on either side of the ATP-binding Table 3 Mutational Analysis of the ALD Gene in IS Unrelated Patients ALDP Patient Phenotype Mutation Consequence Immunoreactivity 1 .................. CALD 825 A-GG K276E + 2.................. AMN 870-2AGAGE291,& 3 .................. CALD 872 G-C E291D 4 .................. AMN 1023 T-IC S342P+ 5 .................. AMN 1166 G-C R389H + 6 .................. CALD 1201 G-AA R401Q + 7 ........ CALD 1415-6 AAG FS@472 8 ........ AMN 1771 G-AA R591Q + 9 ........ Addison 1817 C-T S606L + 10 ................ AMN 1850 G-AA R617H 11 ................ CALD 1876 G-AA A626T 12 ................ Fetus 1884 G-C D629H + 13 ................ CALD 1932 C-UT Q645X 14 ................ AMN 1978 C-OT R660W 15 ........ AMN AExon7-10 Null Mutations in the ALD gene were determined, as described in Methods, in 15 of the ALD patients reported in table 2. Login to comment
178 In 11 patients, missense mutations that occurred throughout the protein were found: within the transmembrane domains (patients 1, 3, and 4), within the ATP-binding domain (patients 8-12), and on either side of the ATP-binding Table 3 Mutational Analysis of the ALD Gene in IS Unrelated Patients ALDP Patient Phenotype Mutation Consequence Immunoreactivity 1 .................. CALD 825 A-GG K276E + 2 .................. AMN 870-2 AGAG E291,& 3 .................. CALD 872 G-C E291D 4 .................. AMN 1023 T-IC S342P + 5 .................. AMN 1166 G-C R389H + 6 .................. CALD 1201 G-AA R401Q + 7 ........ CALD 1415-6 AAG FS@472 8 ........ AMN 1771 G-AA R591Q + 9 ........ Addison 1817 C-T S606L + 10 ................ AMN 1850 G-AA R617H 11 ................ CALD 1876 G-AA A626T 12 ................ Fetus 1884 G-C D629H + 13 ................ CALD 1932 C-UT Q645X 14 ................ AMN 1978 C-OT R660W 15 ........ AMN AExon7-10 Null Mutations in the ALD gene were determined, as described in Methods, in 15 of the ALD patients reported in table 2. Login to comment

[hide] A point mutation at ATP-binding region of the ALD ... Jpn J Hum Genet. 1994 Sep;39(3):345-51. Matsumoto T, Kondoh T, Masuzaki H, Harada N, Matsusaka T, Kinoshita E, Takeo G, Tsujihata M, Suzuki Y, Tsuji Y
A point mutation at ATP-binding region of the ALD gene in a family with X-linked adrenoleukodystrophy.
Jpn J Hum Genet. 1994 Sep;39(3):345-51., [PMID:7841445]

Abstract [show]
A prenatal diagnosis was performed in a family with X-linked adrenoleukodystrophy (ALD). A fetus was at high risk of suffering the disease by segregation analysis and by very long chain fatty acid-CoA synthetase activity assay. A transition (G to A) at codon 617 of the candidate ALD gene was detected by reverse transcription PCR (RT-PCR) based sequencing of the fetal liver RNA. The mutation was located in highly conserved ATP-binding site in this gene and deduced amino acid transversion R617H was thought to be the cause of ALD in this family.

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3 The mutation was located in highly conserved ATP-binding site in this gene and deduced amino acid transversion R617H was thought to be the cause of ALD in this family. Login to comment
92 It is probable that G to A transition in the codon 617 caused AMN/ALD in our family, although it is necessary to elucidate whether this R617H substitution is polymorphism and whether the function of this mutated ALDP is reduced or not. Login to comment

[hide] Novel mutation in ATP-binding domain of ABCD1 gene... J Genet. 2010 Dec;89(4):473-7. Kumar N, Taneja KK, Kumar A, Nayar D, Taneja B, Aneja S, Behari M, Kalra V, Bansal SK
Novel mutation in ATP-binding domain of ABCD1 gene in adrenoleukodystrophy.
J Genet. 2010 Dec;89(4):473-7., [PMID:21273699]

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87 In this codon, out of six possible different missense mutations, (three each at position first and second of the codon) four viz. c.1849C>T / Arg617Cys, c.1849C>G / Arg617Gly, c.1850G>A / Arg617His and c.1850G>T / Arg617Leu have already been reported by others (Fanen et al. 1994; Krasemann et al. 1996; Coll et al. 2005). Login to comment

[hide] Decreased expression of ABCD4 and BG1 genes early ... Hum Mol Genet. 2005 May 15;14(10):1293-303. Epub 2005 Mar 30. Asheuer M, Bieche I, Laurendeau I, Moser A, Hainque B, Vidaud M, Aubourg P
Decreased expression of ABCD4 and BG1 genes early in the pathogenesis of X-linked adrenoleukodystrophy.
Hum Mol Genet. 2005 May 15;14(10):1293-303. Epub 2005 Mar 30., [PMID:15800013]

Abstract [show]
Childhood cerebral adrenoleukodystrophy (CCER), adrenomyeloneuropathy (AMN) and AMN with cerebral demyelination (AMN-C) are the main phenotypic variants of X-linked adrenoleukodystrophy (ALD). It is caused by mutations in the ABCD1 gene encoding a half-size peroxisomal transporter that has to dimerize to become functional. The biochemical hallmark of ALD is the accumulation of very-long-chain fatty acids (VLCFA) in plasma and tissues. However, there is no correlation between the ALD phenotype and the ABCD1 gene mutations or the accumulation of VLCFA in plasma and fibroblast from ALD patients. The absence of genotype-phenotype correlation suggests the existence of modifier genes. To elucidate the mechanisms underlying the phenotypic variability of ALD, we studied the expression of ABCD1, three other peroxisomal transporter genes of the same family (ABCD2, ABCD3 and ABCD4) and two VLCFA synthetase genes (VLCS and BG1) involved in VLCFA metabolism, as well as the VLCFA concentrations in the normal white matter (WM) from ALD patients with CCER, AMN-C and AMN phenotypes. This study shows that: (1) ABCD1 gene mutations leading to truncated ALD protein are unlikely to cause variation in the ALD phenotype; (2) accumulation of saturated VLCFA in normal-appearing WM correlates with ALD phenotype and (3) expression of the ABCD4 and BG1, but not of the ABCD2, ABCD3 and VLCS genes, tends to be correlated with the severity of the disease, acting early in the pathogenesis of ALD.

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76 Mutation Amino acid alteration Type of mutation at the protein level Tissue sample CCER1 521A.G Y174C Missense CCER2 1414insC fsE471 Frame shift CCER3 Unknown Unknown Unknown Fibroblast CCER4 411G.A W137X Nonsense CCER5 1961T.C L654P Missense CCER6 529C.T Q177X Nonsense CCER7 901-1G.A fsE300 Frame shift CCER8 796G.A G266R Missense CCER9 1822G.A G608S Missense Brain CCER10 1390C.A R464X Nonsense CCER11 253-254insC fsP84 Frame shift CCER12 619_627del S207_A209del Deletion AMN-C1 1414-1415insC fsE471 Frame shift AMN-C2 1661G.A R554H Missense AMN-C3 1585delG fsG528 Frame shift Fibroblast AMN-C4 1661G.A R554H Missense AMN-C5 1825G.A E609K Missense AMN-C6 919C.T Q307X Nonsense AMN-C7 1850G.A R617H Missense AMN-C8 887A.G Y296C Missense AMN-C9 965T.C L322P Missense Brain AMN-C10 1390C.T R464X Nonsense AMN-C11 [1165C.T;1224 þ 1GT.TG] [R389C;fSE408] Missense; frame shift AMN-C12 1661G.A R554H Missense AMN-C13 [1997A.C;2007C.G] [Y666S;H669Q] Missense AMN-C14 1755delG fsH586 Frame shift AMN1 529C.T Q177X Nonsense AMN2 1999C.G H667D Missense AMN3 1415delAG fsE471 Frame shift Fibroblast AMN4 337delC fsA112 Frame shift AMN5 310C.T R104C Missense AMN6 919C.T Q307X Nonsense AMN7 323C.T S108L Missense Brain All mutation designations conform to the nomenclature described by Antonarakis and den Dunnen (30,31). Login to comment

[hide] Mutational analysis of patients with X-linked adre... Hum Mutat. 1995;6(2):104-15. Kok F, Neumann S, Sarde CO, Zheng S, Wu KH, Wei HM, Bergin J, Watkins PA, Gould S, Sack G, et al.
Mutational analysis of patients with X-linked adrenoleukodystrophy.
Hum Mutat. 1995;6(2):104-15., [PMID:7581394]

Abstract [show]
Adrenoleukodystrophy (ALD) is an X-linked neurodegenerative disorder characterized by elevated very long chain fatty acid (VLCFA) levels, reduced activity of peroxisomal VLCFA-CoA ligase, and variable phenotypic expression. A putative gene for ALD was recently identified and surprisingly encodes a protein (ALDP) that belongs to a family of transmembrane transporters regulated or activated by ATP (the ABC proteins). We have examined genomic DNA from ALD probands for mutations in the putative ALD gene. We detected large deletions of the carboxyl-terminal portion of the gene in 4 of 112 probands. Twenty-five of the ALD probands whose ALD genes appeared normal by Southern blot analysis were surveyed for mutations by Single Strand Conformation Polymorphism (SSCP) procedures and DNA sequence analysis. SSCP variants were detected in 22 probands and none in 60 X-chromosomes from normal individuals. Mutations were detected in all of the ALD probands. The mutations were distributed throughout the gene and did not correlate with phenotype. Approximately half were non-recurrent missense mutations of which 64% occurred in CpG dinucleotides. There was a cluster of frameshift mutations in a small region of exon 5, including an identical AG deletion in 7 unrelated probands. These data strongly support the supposition that mutations in the putative ALD gene result in ALD.

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131 3' deletion 3' deletion 3' deletion 3' deletion R104C A141T R152C R182P Frameshift at AA 231 G277W R389H Spl mutation at AA 408 Q466 stop Frameshift at AA 470 Frameshift at AA 470 Frameshift at AA 472 Frameshift at AA 472 Frameshift at AA 472 Frameshift at AA 472 Frameshift at AA 472 Frameshift at AA 472 Frameshift at AA 472 G512S M566K S606L L516L R617H R660W - - Exons 3-10 Exons 7-10 Exons 8-10 Exons 7-10 33 Anglos 5 Scott 8 Anglos 7 Anglos 11 Jewish 36 Irish 51 Italian 37 Filipino 28 Anglos 23 Anglos 11 Anglos 8 Anglos 40 Italian 22 German 4 Anglos 5 black 8 Anglos 31 Anglos 10 Anglos 28 Anglos 22 Italian 8 German 35 German 7 Hispanic 28 German 24 Anglos 18 Jewish 9 Hispanic AMNa C E R ~ Cer Add' Cer AMN AMN AMN AMN Cer Cer Cer Add AMN AMN Cer Cer Cer AMN Add AMN AMN Cer AMN Cer AMN AMN AMN 5 Cer,AMN,Add 4 Cer,AMN 1 Cer 5 Cer,AMN,Add 1 4 2 1 2 2 5 Adopted 5 2 15 1 13 2 2 1 Cer AMN AMN,Add AMN Cer,AMN Cer,AMN Cer,AMN,Add ? Login to comment
189 Patient 22 has a G +A transition at nucleotide 1850resulting inthe substitution of histidine for a highly conserved arginine in the ATP binding domain, R617H. Login to comment
234 Four mutations were found within the ATP bind- ing domain, one in Walker A (G512S), one in Walker B (R617H), one in the highly conserved sequence preceding Walker B (S606L),and one in the middle of the domain. Login to comment

[hide] Identification of mutations in the putative ATP-bi... J Clin Invest. 1994 Aug;94(2):516-20. Fanen P, Guidoux S, Sarde CO, Mandel JL, Goossens M, Aubourg P
Identification of mutations in the putative ATP-binding domain of the adrenoleukodystrophy gene.
J Clin Invest. 1994 Aug;94(2):516-20., [PMID:8040304]

Abstract [show]
The recently identified adrenoleukodystrophy (ALD) gene is predicted to encode a peroxisomal protein of 745 amino acids that includes one domain for ATP-binding, termed nucleotide-binding fold (NBF). To determine whether mutations occur in the putative NBF of ALD protein, we analyzed by denaturing gradient gel electrophoresis (DGGE) exon 6 and 8 that encode most part of this domain in 50 ALD patients. Four amino acid substitutions, three frameshift mutations leading to premature termination signal, and a splicing mutation were identified. These amino acid substitutions occurred at residues highly conserved in other ATP-binding cassette (ABC) proteins. In addition, a nonsense mutation was detected in exon 4.

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48 Asterisks indicate the posi- *l I U13 | tion of the four missense mutations in ALD protein (ALDP): R518W substitution occurs at the same amino acid position as in the CFTR mutant S1255P, and S606L at the same position as in the S5491 or S549R CFTR mutants; R617C and R617H have no equivalents in CFTR mutants. Login to comment
93 The third missense mutation (G2236 -- A) involved the same codon (Arg617 -+ His or R617H) and was discovered in a patient who developed AMN with cerebral involvement at 33 years. Login to comment
96 Therefore, the R617H mutation presented by this patient is likely to be a de novo mutation. Login to comment
127 Three of them (S606L, R617C, and R617H) involve invariant residues in all ABC proteins studied so far (Fig. 1). Login to comment
145 Mutations Detected in the ALD Gene Name Nucleotide change Effect on coding sequence Exon Clinical phenotype R464X C - T at 1776 Arg - Stop at 464 4 AMN* 1937delC Deletion of C at 1937 Frameshift 6 cerebral ALD R518W CT at 1938 Arg-Trpat 518 6 AMN 2020 + I G - A G - A at 2020 + 1 5' splice signal Intron 6 ACMN2 2177delTA Deletion of TA at 2177 Frameshift 8 cerebral ALD S606L C - T at 2203 Ser - Leu at 606 8 Addison 2204delG Deletion of G at 2204 Frameshift 8 Addison R617C C - T at 2235 Arg - Cys at 617 8 cerebral ALD R617H G - A at 2236 Arg - His at 617 8 ACMN * Adrenomyeloneuropathy; tadrenomyeloneuropathy with cerebral involvement. Login to comment

[hide] [Adrenoleukodystrophy: structure and function of A... Yakugaku Zasshi. 2007 Jan;127(1):163-72. Takahashi N, Morita M, Imanaka T
[Adrenoleukodystrophy: structure and function of ALDP, and intracellular behavior of mutant ALDP with naturally occurring missense mutations].
Yakugaku Zasshi. 2007 Jan;127(1):163-72., [PMID:17202797]

Abstract [show]
Adrenoleukodystrophy (ALD) is an inherited disorder characterized by progressive demyelination of the central nervous system and adrenal dysfunction. The biochemical characterization is based on the accumulation of pathgnomonic amounts of saturated very long-chain fatty acid (VLCFA; C>22) in all tissues, including the brain white matter, adrenal glands, and skin fibroblasts, of the patients. The accumulation of VLCFA in ALD is linked to a mutation in the ALD (ABCD1) gene, an ABC subfamily D member. The ALD gene product, so-called ALDP (ABCD1), is thought to be involved in the transport of VLCFA or VLCFA-CoA into the peroxisomes. ALDP is a half-sized peroxisomal ABC protein and it has 745 amino acids in humans. ALDP is thought to be synthesized on free polysomes, posttranslationally transported to peroxisomes, and inserted into the membranes. During this process, ALDP interacts with Pex19p, a chaperone-like protein for intracellular trafficking of peroxisomal membrane protein (PMP), the complex targets Pex3p on the peroxisomal membranes, and ALDP is inserted into the membranes. After integration into the membranes, ALDP is thought to form mainly homodimers. Here, we chose nine arbitrary mutations of human ALDP with naturally occurring missense mutations and examined the intracellular behavior of their ALDPs. We found that mutant ALDP (S606L, R617H, and H667D) was degraded together with wild-type ALDP by proteasomes. These results suggest that the complex of mutant and wild-type ALDP is recognized as misfolded proteins and degraded by the protein quality control system associated with proteasomes. Further, we found fragmentation of mutant ALDP (R104C) on peroxisomes and it was not inhibited by proteasomes inhibitors, suggesting that an additional protease(s) is also involved in the quality control of mutant ALDP. In addition, mutation of ALDP (Y174C) suggests that a loop between transmembrane domains 2 and 3 is important for the targeting of ALDP to peroxisomes.

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8 We found that mutant ALDP (S606L, R617H, and H667D) was degraded together with wild-type ALDP by proteasomes. Login to comment
20 R617H and H667D are located in Walker B region and in COOH-terminal region, respectively. Login to comment
28 ミスセンス変異を持つ ALDP の細胞内動態 ―一過性発現による解析 ALD 患者の持つ変異 ALDP の機能,細胞内局在性,細胞内における安定性を解析することは, ALDP の各ドメインの機能を知る上で有用な情報を提供すると思われる．特にミスセンス変異は,たった 1 つのアミノ酸変異による異常であるので特に興味深い．われわれは ALD 患者で報告されているミスセンス変異の中から,TMD から 4 つ(R104C, G116R, Y174C, S342P),NBD から 4 つ(Q544R, S606P, S606L, R617H),C 末端部位から 1 つ (H667D)を任意に選び(Fig. 1),その機能と細胞内動態を解析した．これらの実験は,大学院シンポジウムで報告したので,詳しく述べたいと思う． ALDP はペルオキシソームにおける極長鎖脂肪酸の b 酸化に関与していることが知られている．実際に ALD 患者由来の繊維芽細胞では極長鎖脂肪酸の b 酸化活性が正常な線維芽細胞と比べて約 50 ―70%程度減少している．そこで野生型及び変異型 ALDP の機能を確認するため,ALDP を発現していない ALD 患者由来線維芽細胞に,N 末端に His タグを付加した野生型と変異型 ALDP を一過性に発現し,［1-14 C]lignoceric acid を基質として極長鎖脂肪酸 b 酸化活性の測定を行った．その結果, ALDP 欠損線維芽細胞の極長鎖脂肪酸 b 酸化活性は,正常細胞の約 50%まで減少していたが,野生型 His-ALDP を発現させると正常と同程度にまで活性が回復した．このことから発現させた野生型 His-ALDP は ALDP と同等の機能を持つことが確認された．一方,9 種類のミスセンス変異 ALDP を発現した線維芽細胞では極長鎖脂肪酸 b 酸化活性の増加は認められなかった．よって,これらのミスセンス変異 ALDP は機能を欠くことが確認された．ついで,野生型及び変異型 His-ALDP を発現した ALD 患者線維芽細胞を回収し,変異型 ALDP の発現量を immunoblotting により定量化し解析した(Table 1)．なお ALDP の発現量は,ペルオキシソームの指標酵素であるカタラーゼの発現量で補正した．その結果,変異型 ALDP(R104C, G116R, Y174C, S342P, Q544R, S606P)は,野生型とほぼ同程度の発現量を示した．一方,変異型 ALDP (S606L, R617H, H667D)では発現量が野生型の発 167 Table 1. Login to comment
29 Expression and Localization of Missense ALDPs Mutant Transient Stable Expression Localization b-Oxidation Expression Localization Wild Z Px ＋ Z Px R104C, G116R S342P, Q544R S606P Z Px － Z Px Y174C Z mis － Z mis S606L ＋ Px －－－ R617H ± －－ na na H667D ＋－－－－ Wild and Mutant His-ALDPs or ALDP-GFPs were transiently expressed in X-ALD ˆbroblasts and stably expressed in CHO cells, respectively. Login to comment
36 1 現量と比べて約 50%程度減少していた．なお,各 ALDP ポジティブの細胞は約 30%程度であり,各細胞間での発現効率に有意な差は認められなかった．このことから,ALDP の発現量が減少していた 3 つの変異 ALDP は細胞内での安定性が低下していると推察された．また興味深いことに S606P と S606L は同じ部位の変異にも係わらず,置換したアミノ酸によって発現量には差が認められた．ついで,変異型 His-ALDP の細胞内局在を蛍光抗体法で確認した．変異型 ALDP(R104C, G116R, S342P, Q544R, S606P, S606L)では ALDP がカタラーゼの局在と一致したことから,正常にペルオキシソームへ局在していることが確認された．一方, 変異型 ALDP(Y174C, H667D)では局在が一致せず,ALDP が他の細胞内小器官へ間違って輸送されていると考えられた．変異型 ALDP(R617H) では ALDP の発現が認められなかった．変異型 ALDP(R104C, G116R, S342P, Q544R, S606P)では野生型とほぼ同程度のタンパク量が発現し,ペルオキシソームへの局在も確認されたので,これらの変異型 ALDP は合成されたのちに正常にペルオキシソームに運ばれるが,ペルオキシソーム膜においてその機能(ATP 結合・加水分解若しくは基質輸送)に異常を持つことが推察された．特に R104C, G116R, S342P は TMD に存在することから ALDP の基質輸送能が変化していると考えられる．一方, NBD に存在する Q544R, S606P は ATP 結合・加水分解に影響を与えている可能性が考えられる．また S606P, S606L は変異が同じ部位でも構造的に安定性が異なっていた．Roerig らは S606L の変異型 ALDP は,ATP との親和性が低下している一方で ATP 加水分解は正常に行われていると報告している．29) このことは ALDP と ATP の親和性が ALDP の安定性にも影響を及ぼしている可能性を示している．S606L と S606P の安定性の違いと機能の関係は ALDP の機能を知る上でも興味深い点であり, 今後さらに検討を行う必要がある．一方,Y174C の変異型 ALDP は正常に発現するにも係わらず, ペルオキシソームへ局在せず他の細胞内小器官へミスターゲッティングした．これまでにペルオキシソームへの局在化シグナルを欠くペルオキシソーム膜タンパク質は,非特異的にミトコンドリアや小胞体に移行することが知られている．30,31) よって, ALDP の TMD2―3 の間のループは,ペルオキシソームへの局在化に重要な役割を果たしている可能性が推察される．Pex19p 存在化での in vitro タンパク質翻訳系において,ALDP(Y174C)は Pex19p に結合できるので,ALDP の N 末端 67―164 に存在するペルオキシソーム移行に係わる領域が ALDP の何らかの構造変化によってマスクされるのかもしれない． 5. Login to comment
49 変異型 ALDP の分解過程の解析新生タンパク質が正し̄4;フォールディングを受けることは,そのタンパク質の正常な機能発現のために必須である．遺伝子変異などが存在すると,タンパク質がミスフォールディングされる．このミスフォールドタンパクが細胞外へ分泌されたり,細胞内に蓄積したりすると生体にとって極めて有害になるため,このようなタンパクはプロテアソーム,リソソーム等によって迅速に分解される．ちなみに,嚢胞性線維症の原因タンパク質 CFTR は細胞膜イオンチャネルとして機能する ABC タンパク質であるが,変異 CFTR は小胞体膜からプロテアソームにリクルートされ分解されることが報告されている．32,33) しかしながら,変異型 ALDP を始めとして,ペルオキシソーム膜タンパク質についての解析はほとんど行われていない．変異型 ALDP の一過性発現と安定過剰発現実験より,ALDP(S606L, R617H, H667D, R104C)は, プロテアーゼにより分解されていると推定された．そこで,ALDP-GFP(H667D)を発現している CHO 細胞に各種プロテアーゼ阻害剤を処理し,解析を行った．その結果,プロテアソーム阻害剤である lactacystin を処理した細胞では ALDP-GFP 及び ALDP のバンドが出現した ( Fig. 4 )．一方 , leupeptin, AEBSF, E64d には効果がなかった．また他のプロテアソーム阻害剤である MG132 も有効であった．さらにプロテアソーム阻害剤により分解を逃れた変異型 ALDP-GFP(H667D)の細胞内局在を蛍光抗体法で観察すると,ペルオキシソームに局在していることが確認された．一方,変異型 ALDP(R104C)のフラグメント化は上記プロテアーゼ処理では阻害されなかった．さらに ALD 患者由来細胞の内因性変異 ALDP の分解とプロテアソーム分解系の関与について確認するため,変異型 ALDP(R617H)を持つ患者由来線維芽細胞を用いてタンパク分解の阻害実験を行った．その結果,lactacystin と MG132 処理により, ALDP のバンドが出現した．以上の結果より,ペルオキシソーム膜上にはミスフォールドしたタンパク質を認識する仕組みが存在し,プロテアソーム及び他のプロテアーゼを介して排除していることが示唆された．一方,山田らは ALD 患者線維芽細胞を［35 S］メチオニンでパルスチェイスすることにより,変異型 ALDP(G512S, R660W)の分解が E-64 と leupepu- tin により抑制されることを報告している．34) 彼らの実験ではプロテアソーム阻害剤については実験していないので,プロテアソームの関与は不明であるが,変異型 ALDP の分解には,複数のプロテアーゼが関与している可能性がある． 7. Login to comment
52 Some mutant ALDPs (R104C, G116R, S342P, Q544R and S606P) are normally inserted into the peroxisomal membrane, and others were mislocalized (Y174C) or degraded by proteasome (S606L, R617H and H667D). Login to comment
53 170 Vol. 127 (2007) その結果より,ミスセンス変異 ALDP は以下に示すように 4 種類の細胞内動態を持つことが示された(Fig. 5)．1) 野生型と同様にペルオキシソームに局在するがその機能が阻害されている変異 (R104C, G116R, S342P, Q544R, S606P),2) ペルオキシソームへの局在化に障害がある変異(Y174C), 3) 変異によりタンパク質の安定性が低下しプロテアソームでの分解を受けるが,一部ペルオキシソームに局在する変異(S606L),4) 変異によりタンパク質の安定性が低下しプロテアソームで選択的に分解を受け,細胞内でほとんど確認できない変異 (R617H, H667D)の 4 種類のパターンである．発現量も局在化も正常な変異では,ABC タンパク質としての機能に直接関与している機能ドメインの障害が起こっていると推察される．この中で G116R, S342P は TMD に位置しており,基質の認識や輸送に障害があると推察される．また Q544R, S606P は ATP との結合・加水分解に関与する NBD に位置している．このような変異は,ALDP の ABC タンパク質としての機能を解析するために有益と考えられる．発現量は正常だが局在化に異常が認められた Y174C は,TMD2 と 3 の間のループ 2 に位置しており,この領域が ALDP のペルオキシソームへのターゲッティングに必要であることを示している． ALDP のターゲッティングに必要な領域は 67―164 番目のアミノ酸に存在することが報告されている．20) このことから,Y174C の変異による構造変化のため,ターゲッティングシグナルがマスクされているのかもしれない．このタイプの変異は ALDP のペルオキシソームへの局在化を調べる上で重要と考えられる． ALDP の変異で最も多いミスセンス変異ではその多くが細胞内で分解を受けている．R617H 及び H667D では発現量の著しい低下が認められる．特に安定発現した CHO では immunoblot で検出できなかった．ミスフォールドタンパク質の分解システムの 1 つにプロテアソームによる分解系がある．このタンパク質分解は,生物の様々な高次機能の制御や環境ストレスに応答した恒常性の維持(ストレス応答,タンパク質の品質管理など)に必須な役割を担っている．しかし,小胞体を経由して合成される分泌タンパク質や膜タンパク質に比べて,小胞体を経由しない細胞内タンパク質の品質管理機構はあまり報告されていない．ALDP は遊離のポリソームから直接ペルオキシソームに輸送されるが,この過程でどのように R617H, H667D などの変異が認識され,プロテアソーム系が働いているか興味深い． 171171No. Login to comment
27 df;b9;bb;f3;b9;᜕ᶒఔᢝ௸ ALDP Ĳe;d30;Pde;ᑁ4d5;ɦb; ߟe00;Έe;ឋ˿a;Ife;Ĳb;ఐĴb;Ye3;᪆ ALD <a3;ὅĲe;ᢝ௸᜕ᶒ ALDP Ĳe;a5f;Pfd;,d30;Pde;ᑁc40;ᙠ ឋ,d30;Pde;ᑁĲb;İa;௫Ĵb;b89;b9a;ឋఔYe3;᪆௳Ĵb;௭௼Ĳf;, ALDP Ĳe;ᔜc9;e1;a4;f3;Ĳe;a5f;Pfd;ఔMe5;Ĵb;e0a;௻ᨵᵨĲa;<c5;ᛇ ఔ?d0;f9b;௳Ĵb;௼əd;Ĵf;Ĵc;Ĵb;&#ff0e;ᱯĲb;df;b9;bb;f3;b9;᜕ᶒĲf;,ıf; ௷ıf; 1 ௸Ĳe;a2;df;ce;⏚᜕ᶒĲb;ఐĴb;ᶒe38;௻௢Ĵb;Ĳe;௻ᱯĲb; ‐ᕡdf1;௤&#ff0e;Ĵf;Ĵc;Ĵf;Ĵc;Ĳf; ALD <a3;ὅ௻ᛇȠa;௯Ĵc;௺௤Ĵb; df;b9;bb;f3;b9;᜕ᶒĲe;e2d;İb;఑,TMD İb;఑ 4 ௸(R104C, G116R, Y174C, S342P) ,NBD İb;఑ 4 ௸(Q544R, S606P, S606L, R617H) ,C ʠb;aef;Ze8;f4d;İb;఑ 1 ௸ (H667D)ఔefb;ɢf;Ĳb;⍶ఁ(Fig. 1) ,ıd;Ĳe;a5f;Pfd;௼d30;Pde; ᑁ4d5;ɦb;ఔYe3;᪆௱ıf;&#ff0e;௭Ĵc;఑Ĳe;b9f; a13;Ĳf;,ᜧb66;▾b7;f3;dd; b8;a6;e0;௻ᛇȠa;௱ıf;Ĳe;௻,a73;௱İf;ff0;ఇıf;௤௼əd;௦&#ff0e; ALDP Ĳf;da;eb;aa;ad;b7;bd;fc;e0;Ĳb;İa;௫Ĵb;ᬿ╩⒴ᾦPaa; ⏚Ĳe; b ⏚ᓄĲb;_a2;e0e;௱௺௤Ĵb;௭௼İc;Me5;఑Ĵc;௺௤Ĵb;&#ff0e; b9f;ωb;Ĳb; ALD <a3;ὅᵫᩭĲe;e4a;dad;Rbd;d30;Pde;௻Ĳf;ᬿ╩⒴ᾦPaa; ⏚Ĳe; b ⏚ᓄd3b;ឋİc;b63;e38;Ĳa;dda;dad;Rbd;d30;Pde;௼bd4;ఇ௺d04; 50 ߟ70%a0b;ea6;e1b;c11;௱௺௤Ĵb;&#ff0e;ıd;௭௻[ce;˯f;ɂb;5ca;ఁ᜕ᶒɂb; ALDP Ĳe;a5f;Pfd;ఔNba;a8d;௳Ĵb;ıf;ఉ,ALDP ఔ˿a;Ife;௱௺ ௤Ĳa;௤ ALD <a3;ὅᵫᩭdda;dad;Rbd;d30;Pde;Ĳb;,N ʠb;aef;Ĳb; His bf;b0;ఔed8;4a0;௱ıf;[ce;˯f;ɂb;௼᜕ᶒɂb; ALDP ఔe00;Έe;ឋĲb; ˿a;Ife;௱, &#ff3b;1-14 C]lignoceric acid ఔ9fa;cea;௼௱௺ᬿ╩⒴ ᾦPaa;⏚ b ⏚ᓄd3b;ឋĲe;e2c;b9a;ఔʹc;௷ıf;&#ff0e;ıd;Ĳe;d50;ʧc;, ALDP b20;ʀd;dda;dad;Rbd;d30;Pde;Ĳe;ᬿ╩⒴ᾦPaa;⏚ b ⏚ᓄd3b;ឋ Ĳf;,b63;e38;d30;Pde;Ĳe;d04; 50%ĳe;௻e1b;c11;௱௺௤ıf;İc;,[ce;˯f; ɂb; His-ALDP ఔ˿a;Ife;௯ıb;Ĵb;௼b63;e38;௼Ȝc;a0b;ea6;Ĳb;ĳe;௻ d3b;ឋİc;8de;fa9;௱ıf;&#ff0e;௭Ĳe;௭௼İb;఑˿a;Ife;௯ıb;ıf;[ce;˯f;ɂb; His-ALDP Ĳf; ALDP ௼Ȝc;b49;Ĳe;a5f;Pfd;ఔᢝ௸௭௼İc;Nba; a8d;௯Ĵc;ıf;&#ff0e;e00;Ab9;,9 a2e;ϙe;Ĳe;df;b9;bb;f3;b9;᜕ᶒ ALDP ఔ˿a;Ife;௱ıf;dda;dad;Rbd;d30;Pde;௻Ĳf;ᬿ╩⒴ᾦPaa;⏚ b ⏚ᓄd3b; ឋĲe;ᜉ4a0;Ĳf;a8d;ఉ఑Ĵc;Ĳa;İb;௷ıf;&#ff0e;ఐ௷௺,௭Ĵc;఑Ĳe;df; b9;bb;f3;b9;᜕ᶒ ALDP Ĳf;a5f;Pfd;ఔb20;İf;௭௼İc;Nba;a8d;௯Ĵc; ıf;&#ff0e; ௸௤௻,[ce;˯f;ɂb;5ca;ఁ᜕ᶒɂb; His-ALDP ఔ˿a;Ife;௱ ıf; ALD <a3;ὅdda;dad;Rbd;d30;Pde;ఔ8de;5ce;௱,᜕ᶒɂb; ALDP Ĳe;˿a;Ife;[cf;ఔ immunoblotting Ĳb;ఐĴa;b9a;[cf;ᓄ௱Ye3;᪆௱ ıf;(Table 1) &#ff0e;Ĳa;İa; ALDP Ĳe;˿a;Ife;[cf;Ĳf;,da;eb;aa;ad; b7;bd;fc;e0;Ĳe;ᢣa19;⏗d20;௻௢Ĵb;ab;bf;e9;fc;bc;Ĳe;˿a;Ife;[cf;௻Xdc; b63;௱ıf;&#ff0e;ıd;Ĳe;d50;ʧc;,᜕ᶒɂb; ALDP(R104C, G116R, Y174C, S342P, Q544R, S606P)Ĳf;,[ce;˯f;ɂb;௼ĳb;ĳc; Ȝc;a0b;ea6;Ĳe;˿a;Ife;[cf;ఔ̙a;௱ıf;&#ff0e;e00;Ab9;,᜕ᶒɂb; ALDP (S606L, R617H, H667D)௻Ĳf;˿a;Ife;[cf;İc;[ce;˯f;ɂb;Ĳe;˿a; 167 Table 1. Login to comment
34 167 No. 1 Ife;[cf;௼bd4;ఇ௺d04; 50%a0b;ea6;e1b;c11;௱௺௤ıf;&#ff0e;Ĳa;İa;,ᔜ ALDP dd;b8;c6;a3;d6;Ĳe;d30;Pde;Ĳf;d04; 30%a0b;ea6;௻௢Ĵa;,ᔜ d30;Pde;╹௻Ĳe;˿a;Ife;4b9;᳛Ĳb;ᨵɢf;Ĳa;dee;Ĳf;a8d;ఉ఑Ĵc;Ĳa;İb;௷ ıf;&#ff0e;௭Ĳe;௭௼İb;఑,ALDP Ĳe;˿a;Ife;[cf;İc;e1b;c11;௱௺௤ ıf; 3 ௸Ĳe;᜕ᶒ ALDP Ĳf;d30;Pde;ᑁ௻Ĳe;b89;b9a;ឋİc;f4e;e0b;௱ ௺௤Ĵb;௼?a8;bdf;௯Ĵc;ıf;&#ff0e;ĳe;ıf;‐ᕡdf1;௤௭௼Ĳb; S606P ௼ S606L Ĳf;Ȝc;௲Ze8;f4d;Ĳe;᜕ᶒĲb;ఊfc2;Ĵf;఑ıa;,f6e;?db;௱ ıf;a2;df;ce;⏚Ĳb;ఐ௷௺˿a;Ife;[cf;Ĳb;Ĳf;dee;İc;a8d;ఉ఑Ĵc;ıf;&#ff0e; ௸௤௻,᜕ᶒɂb; His-ALDP Ĳe;d30;Pde;ᑁc40;ᙠఔVcd;ᐝ ᢙf53;cd5;௻Nba;a8d;௱ıf;&#ff0e;᜕ᶒɂb; ALDP(R104C, G116R, S342P, Q544R, S606P, S606L)௻Ĳf; ALDP İc;ab;bf; e9;fc;bc;Ĳe;c40;ᙠ௼e00;Qf4;௱ıf;௭௼İb;఑,b63;e38;Ĳb;da;eb;aa;ad; b7;bd;fc;e0;ఆc40;ᙠ௱௺௤Ĵb;௭௼İc;Nba;a8d;௯Ĵc;ıf;&#ff0e;e00;Ab9;, ᜕ᶒɂb; ALDP(Y174C, H667D)௻Ĳf;c40;ᙠİc;e00;Qf4;ıb; ıa;,ALDP İc;ed6;Ĳe;d30;Pde;ᑁc0f;ᘤb98;ఆ╹⍟௷௺f38;〈௯ Ĵc;௺௤Ĵb;௼ὃ௨఑Ĵc;ıf;&#ff0e;᜕ᶒɂb; ALDP(R617H) ௻Ĳf; ALDP Ĳe;˿a;Ife;İc;a8d;ఉ఑Ĵc;Ĳa;İb;௷ıf;&#ff0e;᜕ᶒɂb; ALDP(R104C, G116R, S342P, Q544R, S606P)௻ Ĳf;[ce;˯f;ɂb;௼ĳb;ĳc;Ȝc;a0b;ea6;Ĳe;bf;f3;d1;af;[cf;İc;˿a;Ife;௱,da;eb; aa;ad;b7;bd;fc;e0;ఆĲe;c40;ᙠఊNba;a8d;௯Ĵc;ıf;Ĳe;௻,௭Ĵc;఑Ĳe; ᜕ᶒɂb; ALDP Ĳf;ᔠᡂ௯Ĵc;ıf;Ĳe;௵Ĳb;b63;e38;Ĳb;da;eb;aa;ad; b7;bd;fc;e0;Ĳb;Έb;௾Ĵc;Ĵb;İc;,da;eb;aa;ad;b7;bd;fc;e0;̳c;Ĳb;İa;௤ ௺ıd;Ĳe;a5f;Pfd;(ATP d50;ᔠfb;4a0;c34;ᑖYe3;Re5;௱İf;Ĳf;9fa;cea;f38; 〈)Ĳb;ᶒe38;ఔᢝ௸௭௼İc;?a8;bdf;௯Ĵc;ıf;&#ff0e;ᱯĲb; R104C, G116R, S342P Ĳf; TMD Ĳb;b58;ᙠ௳Ĵb;௭௼İb;఑ ALDP Ĳe;9fa;cea;f38;〈Pfd;İc;᜕ᓄ௱௺௤Ĵb;௼ὃ௨఑Ĵc;Ĵb;&#ff0e;e00;Ab9;, NBD Ĳb;b58;ᙠ௳Ĵb; Q544R, S606P Ĳf; ATP d50;ᔠfb;4a0;c34; ᑖYe3;Ĳb;f71;aff;ఔe0e;௨௺௤Ĵb;5ef;Pfd;ឋİc;ὃ௨఑Ĵc;Ĵb;&#ff0e;ĳe;ıf; S606P, S606L Ĳf;᜕ᶒİc;Ȝc;௲Ze8;f4d;௻ఊEcb;⌼ḄĲb;b89;b9a; ឋİc;ᶒĲa;௷௺௤ıf;&#ff0e;Roerig ఑Ĳf; S606L Ĳe;᜕ᶒɂb; ALDP Ĳf;,ATP ௼Ĳe;Yaa;Ȥc;ឋİc;f4e;e0b;௱௺௤Ĵb;e00;Ab9;௻ ATP 4a0;c34;ᑖYe3;Ĳf;b63;e38;Ĳb;ʹc;Ĵf;Ĵc;௺௤Ĵb;௼ᛇȠa;௱௺௤ Ĵb;&#ff0e; 29) ௭Ĳe;௭௼Ĳf; ALDP ௼ ATP Ĳe;Yaa;Ȥc;ឋİc; ALDP Ĳe;b89;b9a;ឋĲb;ఊf71;aff;ఔ5ca;ĳc;௱௺௤Ĵb;5ef;Pfd;ឋఔ̙a;௱௺௤ Ĵb;&#ff0e;S606L ௼ S606P Ĳe;b89;b9a;ឋĲe;⍟௤௼a5f;Pfd;Ĳe;_a2;fc2; Ĳf; ALDP Ĳe;a5f;Pfd;ఔMe5;Ĵb;e0a;௻ఊ‐ᕡdf1;௤Fb9;௻௢Ĵa;, eca;f8c;௯఑Ĳb;ʳc;a0e;ఔʹc;௦fc5;⌕İc;௢Ĵb;&#ff0e;e00;Ab9;,Y174C Ĳe;᜕ᶒɂb; ALDP Ĳf;b63;e38;Ĳb;˿a;Ife;௳Ĵb;Ĳb;ఊfc2;Ĵf;఑ıa;, da;eb;aa;ad;b7;bd;fc;e0;ఆc40;ᙠıb;ıa;ed6;Ĳe;d30;Pde;ᑁc0f;ᘤb98;ఆdf; b9;bf;fc;b2;c3;c6;a3;f3;b0;௱ıf;&#ff0e;௭Ĵc;ĳe;௻Ĳb;da;eb;aa;ad;b7; bd;fc;e0;ఆĲe;c40;ᙠᓄb7;b0;ca;eb;ఔb20;İf;da;eb;aa;ad;b7;bd;fc;e0; ̳c;bf;f3;d1;af;cea;Ĳf;,Ϗe;ᱯᶒḄĲb;df;c8;b3;f3;c9;ea;a2;ఌc0f;Pde; f53;Ĳb;Ofb;ʹc;௳Ĵb;௭௼İc;Me5;఑Ĵc;௺௤Ĵb;&#ff0e; 30,31) ఐ௷௺, ALDP Ĳe; TMD2ߟ3 Ĳe;╹Ĳe;eb;fc;d7;Ĳf;,da;eb;aa;ad;b7; bd;fc;e0;ఆĲe;c40;ᙠᓄĲb;[cd;⌕Ĳa;f79;ᒘఔʧc;ıf;௱௺௤Ĵb;5ef;Pfd; ឋİc;?a8;bdf;௯Ĵc;Ĵb;&#ff0e;Pex19p b58;ᙠᓄ௻Ĳe; in vitro bf;f3; d1;af;cea;ffb;a33;cfb;Ĳb;İa;௤௺,ALDP(Y174C)Ĳf; Pex19p Ĳb;d50;ᔠ௻İd;Ĵb;Ĳe;௻,ALDP Ĳe; N ʠb;aef; 67ߟ164 Ĳb;b58;ᙠ௳Ĵb;da;eb;aa;ad;b7;bd;fc;e0;Ofb;ʹc;Ĳb;fc2;Ĵf;Ĵb;♚9df;İc; ALDP Ĳe;f55;఑İb;Ĳe;Ecb;⌼᜕ᓄĲb;ఐ௷௺de;b9;af;௯Ĵc;Ĵb; Ĳe;İb;ఊ௱Ĵc;Ĳa;௤&#ff0e; 5. Login to comment
46 ᜕ᶒɂb; ALDP Ĳe;ᑖYe3;Έe;a0b;Ĳe;Ye3;᪆ Ab0;˯f;bf;f3;d1;af;cea;İc;b63;௱௤d5;a9;fc;eb;c7;a3;f3;b0;ఔ5d7;௫ Ĵb;௭௼Ĳf;,ıd;Ĳe;bf;f3;d1;af;cea;Ĳe;b63;e38;Ĳa;a5f;Pfd;˿a;Ife;Ĳe;ıf;ఉ Ĳb;fc5;♐௻௢Ĵb;&#ff0e;΋a;f1d;b50;᜕ᶒĲa;௽İc;b58;ᙠ௳Ĵb;௼,bf;f3; d1;af;cea;İc;df;b9;d5;a9;fc;eb;c7;a3;f3;b0;௯Ĵc;Ĵb;&#ff0e;௭Ĳe;df;b9;d5; a9;fc;eb;c9;bf;f3;d1;af;İc;d30;Pde;᜜ఆᑖccc;௯Ĵc;ıf;Ĵa;,d30;Pde;ᑁ Ĳb;Tc4;a4d;௱ıf;Ĵa;௳Ĵb;௼˯f;f53;Ĳb;௼௷௺ᬿఉ௺ᨵbb3;Ĳb;Ĳa;Ĵb; ıf;ఉ,௭Ĳe;ఐ௦Ĳa;bf;f3;d1;af;Ĳf;d7;ed;c6;a2;bd;fc;e0;,ea;bd; bd;fc;e0;b49;Ĳb;ఐ௷௺fc5;΅f;Ĳb;ᑖYe3;௯Ĵc;Ĵb;&#ff0e;௵Ĳa;ĳf;Ĳb;,8a2; Pde;ឋdda;dad;Kc7;Ĳe;țf;8e0;bf;f3;d1;af;cea; CFTR Ĳf;d30;Pde;̳c;a4;aa; f3;c1;e3;cd;eb;௼௱௺a5f;Pfd;௳Ĵb; ABC bf;f3;d1;af;cea;௻௢Ĵb; İc;,᜕ᶒ CFTR Ĳf;c0f;Pde;f53;̳c;İb;఑d7;ed;c6;a2;bd;fc;e0;Ĳb; ea;af;eb;fc;c8;௯Ĵc;ᑖYe3;௯Ĵc;Ĵb;௭௼İc;ᛇȠa;௯Ĵc;௺௤ Ĵb;&#ff0e; 32,33) ௱İb;௱Ĳa;İc;఑,᜕ᶒɂb; ALDP ఔ;cb;ఉ௼௱ ௺,da;eb;aa;ad;b7;bd;fc;e0;̳c;bf;f3;d1;af;cea;Ĳb;௸௤௺Ĳe;Ye3;᪆ Ĳf;ĳb;௼క௽ʹc;Ĵf;Ĵc;௺௤Ĳa;௤&#ff0e; ᜕ᶒɂb; ALDP Ĳe;e00;Έe;ឋ˿a;Ife;௼b89;b9a;Έe;ᒖ˿a;Ife;b9f; a13; ఐĴa;,ALDP (S606L, R617H, H667D, R104C) Ĳf;, d7;ed;c6;a2;fc;bc;Ĳb;ఐĴa;ᑖYe3;௯Ĵc;௺௤Ĵb;௼?a8;b9a;௯Ĵc;ıf;&#ff0e; ıd;௭௻,ALDP-GFP(H667D)ఔ˿a;Ife;௱௺௤Ĵb; CHO d30;Pde;Ĳb;ᔜa2e;d7;ed;c6;a2;fc;bc;σb;bb3;ᒐఔ3e6;ᳮ௱,Ye3; ᪆ఔʹc;௷ıf;&#ff0e;ıd;Ĳe;d50;ʧc;,d7;ed;c6;a2;bd;fc;e0;σb;bb3;ᒐ௻௢ Ĵb; lactacystin ఔ3e6;ᳮ௱ıf;d30;Pde;௻Ĳf; ALDP-GFP 5ca;ఁ ALDP Ĳe; d0; f3; c9; İc; 3fa; Ife; ௱ ıf; ( Fig. 4 ) &#ff0e; e00; Ab9; , leupeptin, AEBSF, E64d Ĳb;Ĳf;4b9;ʧc;İc;Ĳa;İb;௷ıf;&#ff0e;ĳe; ıf;ed6;Ĳe;d7;ed;c6;a2;bd;fc;e0;σb;bb3;ᒐ௻௢Ĵb; MG132 ఊᨵ4b9; ௻௢௷ıf;&#ff0e;௯఑Ĳb;d7;ed;c6;a2;bd;fc;e0;σb;bb3;ᒐĲb;ఐĴa;ᑖYe3; ఔ⌫Ĵc;ıf;᜕ᶒɂb; ALDP-GFP(H667D)Ĳe;d30;Pde;ᑁc40; ᙠఔVcd;ᐝᢙf53;cd5;௻Yb3;bdf;௳Ĵb;௼,da;eb;aa;ad;b7;bd;fc;e0;Ĳb; c40;ᙠ௱௺௤Ĵb;௭௼İc;Nba;a8d;௯Ĵc;ıf;&#ff0e;e00;Ab9;,᜕ᶒɂb; ALDP (R104C) Ĳe;d5;e9;b0;e1;f3;c8;ᓄĲf;e0a;a18;d7;ed;c6;a2;fc; bc;3e6;ᳮ௻Ĳf;σb;bb3;௯Ĵc;Ĳa;İb;௷ıf;&#ff0e; ௯఑Ĳb; ALD <a3;ὅᵫᩭd30;Pde;Ĳe;ᑁ8e0;ឋ᜕ᶒ ALDP Ĳe;ᑖYe3;௼d7;ed;c6;a2;bd;fc;e0;ᑖYe3;cfb;Ĳe;_a2;e0e;Ĳb;௸௤௺Nba;a8d; ௳Ĵb;ıf;ఉ,᜕ᶒɂb; ALDP(R617H)ఔᢝ௸<a3;ὅᵫ ᩭdda;dad;Rbd;d30;Pde;ఔᵨ௤௺bf;f3;d1;af;ᑖYe3;Ĳe;σb;bb3;b9f; a13;ఔʹc; ௷ıf;&#ff0e;ıd;Ĳe;d50;ʧc;,lactacystin ௼ MG132 3e6;ᳮĲb;ఐĴa;, ALDP Ĳe;d0;f3;c9;İc;3fa;Ife;௱ıf;&#ff0e;ee5;e0a;Ĳe;d50;ʧc;ఐĴa;,da; eb;aa;ad;b7;bd;fc;e0;̳c;e0a;Ĳb;Ĳf;df;b9;d5;a9;fc;eb;c9;௱ıf;bf;f3;d1; af;cea;ఔa8d;b58;௳Ĵb;ed5;d44;ĳf;İc;b58;ᙠ௱,d7;ed;c6;a2;bd;fc;e0;5ca; ఁed6;Ĳe;d7;ed;c6;a2;fc;bc;ఔecb;௱௺᣸◀௱௺௤Ĵb;௭௼İc;̙a; ᖂ௯Ĵc;ıf;&#ff0e; e00;Ab9;,c71;ᵪ఑Ĳf; ALD <a3;ὅdda;dad;Rbd;d30;Pde;ఔ &#ff3b;35 S&#ff3d; e1;c1; aa;cb;f3;௻d1;eb;b9;c1;a7;a4;b9;௳Ĵb;௭௼Ĳb;ఐĴa;,᜕ᶒɂb; ALDP (G512S, R660W) Ĳe;ᑖYe3;İc; E-64 ௼ leupepu- tin Ĳb;ఐĴa;ᢓᑴ௯Ĵc;Ĵb;௭௼ఔᛇȠa;௱௺௤Ĵb;&#ff0e; 34) f7c;఑ Ĳe;b9f; a13;௻Ĳf;d7;ed;c6;a2;bd;fc;e0;σb;bb3;ᒐĲb;௸௤௺Ĳf;b9f; a13;௱ ௺௤Ĳa;௤Ĳe;௻,d7;ed;c6;a2;bd;fc;e0;Ĳe;_a2;e0e;Ĳf;e0d;ʔe;௻௢Ĵb; İc;,᜕ᶒɂb; ALDP Ĳe;ᑖYe3;Ĳb;Ĳf;,⋋ᦪĲe;d7;ed;c6;a2;fc; bc;İc;_a2;e0e;௱௺௤Ĵb;5ef;Pfd;ឋİc;௢Ĵb;&#ff0e; 7. Login to comment

[hide] A family with combined mutations of the hemophilia... Neurogenetics. 2008 Jul;9(3):215-8. Epub 2008 May 15. Fogel BL, Young P, Thompson AR, Perlman S
A family with combined mutations of the hemophilia A and X-linked adrenoleukodystrophy genes.
Neurogenetics. 2008 Jul;9(3):215-8. Epub 2008 May 15., [PMID:18481121]

Abstract [show]
X-linked adrenoleukodystrophy and hemophilia A are two distinct, potentially devastating, genetic diseases whose corresponding genes are located in close proximity on the X chromosome. Here we report a family with members affected with both conditions, only the second such family ever reported. Although a structural genomic rearrangement involving both genes was initially predicted to underlie this extremely rare phenotype, genotyping revealed the unlikely occurrence of two individual point mutations. Given the impact of this result on the heritability of the two disorders within the family, this case illustrates the significance of performing detailed molecular analysis in patients with multiple genetic disorders.

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56 The R617H mutation, in exon 8, lies within the ATP-binding domain [6] and results in complete absence of the protein in fibroblast cell lines by immunofluorescence detection, presumably through protein destabilization [6]. Login to comment
57 Table 1 The clinical phenotypes of the proband and other family members are shown IV-16 IV-15 III-10 III-4 Age 19 22 51 61 Onset age (ALD) 17 asymp asymp asymp Cognition - - - - Dysarthria - - - - CN/Bulbar palsies - - - - Visual loss - - - - Pes cavus + + + - Amyotrophy distal - - - Weakness distal - - - ↓ Touch/pain - - - - ↓ Vibration + + + - ↓ Temperature + - - - ↓ Proprioception + - - - Leg spasticity + + + - Hyper-reflexia + + + - Extensor plantars + + + - Ataxia - - - - Gait spastic - - - EPS - - - - Bladder dysfunction + - - - Epilepsy - - - - Factor VIII 5% 4% np 5% C26:0 (μmol/L) 2.37 2.84 1.54 0.73 ACTH (pg/mL) 728 144 11 9 F8 Mutation np np np L1929P ABCD1 Mutation R617H R617H R617H - EMG AOC np np np NCS ASM np np np MRI DWM np np np Plus sign indicates a feature is present, minus sign indicates normal function or absence of the specified finding, downwards arrow indicates reduced sensation. Login to comment
67 Of interest, a recent molecular analysis of 21 ALD Portuguese families did not identify the R617H mutation [13] suggesting that the ALD mutations in these two families are distinct, although it is unclear if any members from the original family described with hemophilia A were included in the analysis. Login to comment
58 Table 1 The clinical phenotypes of the proband and other family members are shown IV-16 IV-15 III-10 III-4 Age 19 22 51 61 Onset age (ALD) 17 asymp asymp asymp Cognition - - - - Dysarthria - - - - CN/Bulbar palsies - - - - Visual loss - - - - Pes cavus + + + - Amyotrophy distal - - - Weakness distal - - - ࢑ Touch/pain - - - - ࢑ Vibration + + + - ࢑ Temperature + - - - ࢑ Proprioception + - - - Leg spasticity + + + - Hyper-reflexia + + + - Extensor plantars + + + - Ataxia - - - - Gait spastic - - - EPS - - - - Bladder dysfunction + - - - Epilepsy - - - - Factor VIII 5% 4% np 5% C26:0 (bc;mol/L) 2.37 2.84 1.54 0.73 ACTH (pg/mL) 728 144 11 9 F8 Mutation np np np L1929P ABCD1 Mutation R617H R617H R617H - EMG AOC np np np NCS ASM np np np MRI DWM np np np Plus sign indicates a feature is present, minus sign indicates normal function or absence of the specified finding, downwards arrow indicates reduced sensation. Login to comment
68 Of interest, a recent molecular analysis of 21 ALD Portuguese families did not identify the R617H mutation [13] suggesting that the ALD mutations in these two families are distinct, although it is unclear if any members from the original family described with hemophilia A were included in the analysis. Login to comment

[hide] Suppression of peroxisomal membrane protein defect... Hum Mol Genet. 1998 Feb;7(2):239-47. Braiterman LT, Zheng S, Watkins PA, Geraghty MT, Johnson G, McGuinness MC, Moser AB, Smith KD
Suppression of peroxisomal membrane protein defects by peroxisomal ATP binding cassette (ABC) proteins.
Hum Mol Genet. 1998 Feb;7(2):239-47., [PMID:9425230]

Abstract [show]
X-Linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disorder characterized by reduced peroxisomal very long chain fatty acid (VLCFA) beta-oxidation. The X - ALD gene product (ALDP) is a peroxisomal transmembrane protein with an ATP binding cassette (ABC). ALDP and three other ABC proteins (PMP70, ALDR, P70R) localize to the peroxisomal membrane. The function of this family of peroxisomal membrane proteins is unknown. We used complementation studies to begin analysis of their role in VLCFA beta-oxidation and on the peroxisomal membrane. Expression of either ALDP or PMP70 restores VLCFA beta-oxidation in X-ALD fibroblasts, indicating overlapping functions. Their expression also restores peroxisome biogenesis in cells that are deficient in the peroxisomal membrane protein Pex2p. Thus it is likely that complex protein interactions are involved in the function and biogenesis of peroxisomal membranes that may contribute to disease heterogeneity.

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184 Mutant ALDP cDNAs were generated by TA cloning (Invitrogen) of RT-PCR products generated from RNA isolated from patient fibroblast cell lines harboring either the R617H mutation that both destablizes and inactivates ALDP or the missense mutation R591Q that inactivates ALDP without altering stability of the protein (5). Login to comment
183 Mutant ALDP cDNAs were generated by TA cloning (Invitrogen) of RT-PCR products generated from RNA isolated from patient fibroblast cell lines harboring either the R617H mutation that both destablizes and inactivates ALDP or the missense mutation R591Q that inactivates ALDP without altering stability of the protein (5). Login to comment
185 Mutant ALDP cDNAs were generated by TA cloning (Invitrogen) of RT-PCR products generated from RNA isolated from patient fibroblast cell lines harboring either the R617H mutation that both destablizes and inactivates ALDP or the missense mutation R591Q that inactivates ALDP without altering stability of the protein (5). Login to comment

[hide] Functional hot spots in human ATP-binding cassette... Protein Sci. 2010 Nov;19(11):2110-21. Kelly L, Fukushima H, Karchin R, Gow JM, Chinn LW, Pieper U, Segal MR, Kroetz DL, Sali A
Functional hot spots in human ATP-binding cassette transporter nucleotide binding domains.
Protein Sci. 2010 Nov;19(11):2110-21., [PMID:20799350]

Abstract [show]
The human ATP-binding cassette (ABC) transporter superfamily consists of 48 integral membrane proteins that couple the action of ATP binding and hydrolysis to the transport of diverse substrates across cellular membranes. Defects in 18 transporters have been implicated in human disease. In hundreds of cases, disease phenotypes and defects in function can be traced to nonsynonymous single nucleotide polymorphisms (nsSNPs). The functional impact of the majority of ABC transporter nsSNPs has yet to be experimentally characterized. Here, we combine experimental mutational studies with sequence and structural analysis to describe the impact of nsSNPs in human ABC transporters. First, the disease associations of 39 nsSNPs in 10 transporters were rationalized by identifying two conserved loops and a small alpha-helical region that may be involved in interdomain communication necessary for transport of substrates. Second, an approach to discriminate between disease-associated and neutral nsSNPs was developed and tailored to this superfamily. Finally, the functional impact of 40 unannotated nsSNPs in seven ABC transporters identified in 247 ethnically diverse individuals studied by the Pharmacogenetics of Membrane Transporters consortium was predicted. Three predictions were experimentally tested using human embryonic kidney epithelial (HEK) 293 cells stably transfected with the reference multidrug resistance transporter 4 and its variants to examine functional differences in transport of the antiviral drug, tenofovir. The experimental results confirmed two predictions. Our analysis provides a structural and evolutionary framework for rationalizing and predicting the functional effects of nsSNPs in this clinically important membrane transporter superfamily.

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50 Disease-associated nsSNPs at Three Structural Hotspots in Human ABC Transporter NBDs Gene Disease Position ARA motif ABCB11 BRIC2 A570T ABCD1 X-ALD A616V CFTR CF A559T ABCC6 PXE R765Q ABCC8 HHF1 R841G ABCC8 HHF1 R1493Q ABCC8 HHF1 R1493W ABCD1 X-ALD R617C ABCD1 X-ALD R617G ABCD1 X-ALD R617H CFTR CF R560K CFTR CF R560S CFTR CF R560T ABCA1 HDLD1 A1046D ABCB4 ICP A546D C-loop 1 motif ABCC8 HHF1 D1471H ABCC8 HHF1 D1471N CFTR CBAVD G544V ABCC8 HHF1 G1478R C-loop2 motif ABCA4 STGD1 H2128R ABCC8 HHF1 K889T ABCD1 X-ALD R660P ABCD1 X-ALD R660W ABCA1 HDLD2 M1091T ABCA4 STGD1 E2131K ABCA12 LI2 E1539K ABCA4 STGD1 and CORD3 E1122K CFTR CF L610S ABCC8 HHF1 L1543P ABCA1 Colorectal cancer sample; somatic mutation A2109T ABCC9 CMD1O A1513T ABCD1 X-ALD H667D CFTR CF A613T ABCA1 HDLD2 D1099Y ABCD1 X-ALD T668I CFTR CF D614G ABCA4 STGD1 R2139W ABCA4 STGD1 R1129C ABCA4 ARMD2, STGD1, and FFM R1129L Disease abbreviations are as follows: BRIC2, benign recurrent intrahepatic cholestasis type 2; X-ALD, X-linked adrenoleukodystrophy; CF, cystic fibrosis; PXE, Pseudoxanthoma elasticum; HHF1, familial hyperinsulinemic hypoglycemia-1; HDLD1, high density lipoprotein deficiency type 1; ICP, intrahepatic cholestasis of pregnancy; CBAVD, congenital bilateral absence of the vas deferens; STGD1, Stargardt disease type 1; HDLD2, high density lipoprotein deficiency type 2; LI2, ichthyosis lamellar type 2; CORD3, cone-rod dystrophy type 3; CMD1O, cardiomyopathy dilated type 1O; ARMD2, age-related macular degeneration type 2; FFM, fundus flavimaculatus. Login to comment

[hide] Mutations, clinical findings and survival estimate... PLoS One. 2012;7(3):e34195. doi: 10.1371/journal.pone.0034195. Epub 2012 Mar 29. Pereira Fdos S, Matte U, Habekost CT, de Castilhos RM, El Husny AS, Lourenco CM, Vianna-Morgante AM, Giuliani L, Galera MF, Honjo R, Kim CA, Politei J, Vargas CR, Jardim LB
Mutations, clinical findings and survival estimates in South American patients with X-linked adrenoleukodystrophy.
PLoS One. 2012;7(3):e34195. doi: 10.1371/journal.pone.0034195. Epub 2012 Mar 29., [PMID:22479560]

Abstract [show]
In this study, we analyzed the ABCD1 gene in X-linked adrenoleukodystrophy (X-ALD) patients and relatives from 38 unrelated families from South America, as well as phenotypic proportions, survival estimates, and the potential effect of geographical origin in clinical characteristics. METHODS: X- ALD patients from Brazil, Argentina and Uruguay were invited to participate in molecular studies to determine their genetic status, characterize the mutations and improve the genetic counseling of their families. All samples were screened by SSCP analysis of PCR fragments, followed by automated DNA sequencing to establish the specific mutation in each family. Age at onset and at death, male phenotypes, genetic status of women, and the effect of family and of latitude of origin were also studied. RESULTS: We identified thirty-six different mutations (twelve novel). This population had an important allelic heterogeneity, as only p.Arg518Gln was repeatedly found (three families). Four cases carried de novo mutations. Intra-familiar phenotype variability was observed in all families. Out of 87 affected males identified, 65% had the cerebral phenotype (CALD). The mean (95% CI) ages at onset and at death of the CALD were 10.9 (9.1-12.7) and 24.7 (19.8-29.6) years. No association was found between phenotypic manifestations and latitude of origin. One index-case was a girl with CALD who carried an ABCD1 mutation, and had completely skewed X inactivation. CONCLUSIONS: This study extends the spectrum of mutations in X-ALD, confirms the high rates of de novo mutations and the absence of common mutations, and suggests a possible high frequency of cerebral forms in our population.

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24 Family/Index case Phenotype at diagnosis Mutation Exon/IVS Mutation type Effect on protein (cDNA) Effect on protein (mRNA) Protein localization Origin of mutations Origin of family 1/Female asymptomatic p.Gly512Ser (Feigenbaum V et al. 1996) E6 Missense c.1534G.A GGC.AGC NBF de novo Southern Brazil 2/Female asymptomatic p.Ser606Leu (Fanen P et al., 1994) E8 Missense c.1817C.T UCG.UUG NBF Inherited Southern Brazil 3/Male AMN p.Trp601X (Gartner J et al.,1998) E8 Stop codon c.1802C.A Truncated NBF Inherited Southern Brazil 4/Female asymptomatic p.Arg617His (Fanen P et al., 1994) E8 Missense c.1850G.A CGC.CAC NBF ND Southern Brazil 5/Male AMN p.Pro623Leu # E9 Missense c.1868C.T CCC.CUC NBF Inherited Southern Brazil 6/Male AO p.Trp326X (Barcelo A et al, 1996) E2 Stop codon c.978G.A Truncated TMD Inherited Southern Brazil 8/Female asymptomatic p.Glu577X # E7 Stop codon c.1729G.T Truncated NBF Inherited Southern Brazil 9/Male asymptomatic p.Arg554His (Smith KD et al., 1999) E7 Missense c.1661G.A CGU.CAU NBF Inherited Southern Brazil 10/Male CALD p.Arg518Gln (Imamura A et al., 1997) E6 Missense c.1553G.A CGG.CAG NBF Inherited Southern Brazil 11/Male AO p.Tyr33_Pro34fsX34 # E1A Frameshift+stop codon c.99_102delC Truncated - Inherited Southern Brazil 12/Female asymptomatic p.Gly266Arg (Fuchs S et al., 1994) E7 Missense c.1653insG Truncated TMD ND Southern Brazil 20/Male CALD p.Arg538fs # E6 Frameshift c.1614_1615dup27 Elonged NBF de novo Southern Brazil 21/Male CALD p.Ala232fsX64 # E2 Frameshift+stop codon c.696_697del11 Truncated TMD Inherited Southern Brazil 22/Male CALD p.Trp137fsX57 # E1B Frameshift+stop codon c.411_412insC Truncated TMD Inherited Northern Brazil 23/Male asymptomatic p.Trp679X (Waterham HR et al, 1998) E10 Stop codon c.2037G.A Truncated NBF ND Southern Brazil 24/Male AO p.Tyr296Cys (Takano H et al., 1999) E2 Missense c.887A.G UAU.UGU TMD Inherited Southern Brazil 27/Male CALD p.Leu628Glu # E9 Missense c.1883T.A CUG.GAG NBF Inherited Southern Brazil 29/Male CALD p.Pro546fsX? Login to comment

[hide] Granny trips down: is she carrying the big bad wol... Neurol Sci. 2013 Nov;34(11):2077-9. doi: 10.1007/s10072-012-1108-8. Epub 2012 May 17. Tremolizzo L, Patassini M, Uziel G, Castellotti B, Gellera C, Ferrarese C, Appollonio I
Granny trips down: is she carrying the big bad wolf?
Neurol Sci. 2013 Nov;34(11):2077-9. doi: 10.1007/s10072-012-1108-8. Epub 2012 May 17., [PMID:22592565]

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21 In fact, genetic analysis of the ABCD1 gene demonstrated the presence of the mutation p.R617H within exon 8. Login to comment

[hide] Progression rate of myelopathy in X-linked adrenol... Metab Brain Dis. 2015 Oct;30(5):1279-84. doi: 10.1007/s11011-015-9672-2. Epub 2015 Apr 30. Habekost CT, Pereira FS, Vargas CR, Coelho DM, Torrez V, Oses JP, Portela LV, Schestatsky P, Felix VT, Matte U, Torman VL, Jardim LB
Progression rate of myelopathy in X-linked adrenoleukodystrophy heterozygotes.
Metab Brain Dis. 2015 Oct;30(5):1279-84. doi: 10.1007/s11011-015-9672-2. Epub 2015 Apr 30., [PMID:25920484]

Abstract [show]
X-linked adrenoleukodystrophy heterozygote women can present adult onset myeloneuropathy and little is known about its natural history. We aimed to describe the progression rate of the neurological impairment in the prospective follow-up of our cohort and to look for prognostic factors. The neurological scales Japanese Orthopaedic Association (JOA) and Severity Score System for Progressive Myelopathy (SSPROM) were applied at baseline in 29 symptomatic carriers and in follow-up visits. Age at onset, disease duration, X inactivation pattern, determination of the allele expressed, plasma levels of the very long chain fatty acids and of the neuron-specific enolase, and somato-sensory evoked potentials, were taken at baseline. The slope of the linear regression of both JOA and SSPROM versus disease duration since the first symptom was estimated using mixed modeling. JOA and SSPROM decreased 0.42 and 1.87 points per year, respectively (p < 0.001). None of the parameters under study influenced these rates. We estimated that the number of carriers per arm needed in a future 12 month trial with 80% power and a 50% reduction in disease progression would be 225 women for JOA and 750 for SSPROM. The progression rates of the studied neurological scales were small, did not depend on any modifier factor known, and reflected the characteristically slow worsening of symptoms in X-ALD heterozygotes. Better biomarkers are still necessary for future studies.

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46 Primers for exons 3, 6, 7 and 8, where the mutations carried by those with skewed inactivation patterns - p.Arg401Trp, p.Arg518Gln, p.Glu577X and p.Arg617His - are located, were used to amplify the cDNA. Login to comment

[hide] Eight novel mutations in the ABCD1 gene and clinic... World J Pediatr. 2015 Nov;11(4):366-73. doi: 10.1007/s12519-015-0044-0. Epub 2015 Oct 11. Chu SS, Ye J, Zhang HW, Han LS, Qiu WJ, Gao XL, Gu XF
Eight novel mutations in the ABCD1 gene and clinical characteristics of 25 Chinese patients with X-linked adrenoleukodystrophy.
World J Pediatr. 2015 Nov;11(4):366-73. doi: 10.1007/s12519-015-0044-0. Epub 2015 Oct 11., [PMID:26454440]

Abstract [show]
BACKGROUND: X-linked adrenoleukodystrophy (X-ALD) is a fatal neurodegenerative disease caused by mutations in the adenosine triphosphate-binding cassette D1 (ABCD1) gene. This study aimed to retrospectively investigate the clinical characteristics of 25 patients with X-ALD including members of large pedigrees, to analyze ABCD1 gene mutations, the effect of gene novel variants on ALD protein (ALDP) structure and function, and to expand gene mutation spectrum of Chinese patients. METHODS: Twenty-five male patients diagnosed with X-ALD were enrolled in this study. The clinical characteristics of the patients were retrospectively summarized by reviewing medical records or telephone consultation. ABCD1 gene mutations were analyzed. The pathogenicity of novel missense variants was analyzed using cobalt constraint-based multiple protein alignment tool, polymorphism phenotyping, sorting intolerant from tolerant, Align-Grantham variation and Grantham deviation, and Swiss-Program Database Viewer 4.04 software, respectively. RESULTS: Childhood cerebral form ALD (CCALD) is the most common phenotype (64%) in the 25 patients with X-ALD. The progressive deterioration of neurological and cognitive functions is the main clinical feature. The demyelination of the brain white matter and elevated plasma very long chain fatty acids (VLCFAs) were found in all patients. Different phenotypes were also presented within family members of the patients. Twenty-two different mutations including 8 novel mutations in the ABCD1 gene were identified in the 25 patients. Of the mutations, 63.6% were missense mutations and 34.8% located in exon 1. The amino acid residues of three novel missense mutations in eight species were highly conserved, and were predicted to be "probably" damaging to ALDP function. The other five novel mutations were splice, nonsense, deletion or duplication mutations. CONCLUSIONS: CCALD is the most common phenotype (64%) in our patients with X-ALD. Eight novel mutations in the ABCD1 gene identified are disease-causing mutations. Brain magnetic resonance imaging and plasma VLCFA determination should be performed for the patients who present with progressive deterioration of neurological development.

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111 However, some X-ALD males remain asymptomatic and one-third of heterozygous women remain free of clinical symptoms during their Patient number Exon Nucleotide change Amino acid change Protein localization References P1 2 c.1017G>T p.Trp339Cys TMD Novel P2 8 c.1850G>A p.Arg617His NBD Fanen et al, 1994[12] P4 1 c.892G>C p.Gly298Arg TMD Novel P5, P6 5 c.1415_16delAG p.Gln472Argfs*83 TMD to NBD Barcelo et al, 1994[13] P7 1 c.532C>T p.Gln178* TMD Novel P8 1 c.473T>C p.Leu158Pro TMD The peroxisomal diseases laboratory (unpublished) P10 6 c.1552C>T p.Arg518Trp NBD Fanen et al, 1994[12] P11 3 c.1202G>A p.Arg401Gln TMD to NBD Fuchs et al, 1994[14] P12 1 c.887A>G p.Tyr296Cys TMD Takano et al, 1999[15] P13 1 c.893G>A p.Gly298Asp TMD Lachtermacher et al, 2000[16] P14 1 c.310C>T p.Arg104Cys TMD Kok et al, 1995[17] P15 IVS 8 c.1866-10G>A p.Pro623fs* NBD Kemp et al, 1995[18] P16 5 c.1428C>A p.Cys476* NBD Novel P17 5 c.1421T>C p.Ile474Thr NBD Shimozawa et al, 2011[19] P18 6 c.1538A>G p.Lys513Arg NBD Piti&#e9;-Salp&#e9;tri&#e8;re Hospital (unpublished) P19 1 c.310C>T p.Arg104Cys TMD Kok et al, 1995[17] P20 6 c.1544C>A p.Ser515Tyr NBD Novel P21 2 c.901-1G>A p.Val301fs* TMD Kemp et al, 2001[20] P22 2 c.974T>C p.Leu325Pro TMD The peroxisomal diseases laboratory (unpublished) P23 3 c.1182delG p.Ala395Leufs*15 TMD to NBD Novel P24 1 c.424delC p.Leu142Serfs*56 TMD Novel P25 7 c.1759_1761dup p.Ile588His NBD Novel Table 2. Login to comment