ABCMdb

ABCA4 p.Thr1428Met

ClinVar:	c.4283C>T , p.Thr1428Met N , Benign/Likely benign, not provided
Predicted by SNAP2:	A: N (72%), C: N (66%), D: N (66%), E: N (72%), F: D (91%), G: N (66%), H: N (78%), I: N (66%), K: N (78%), L: N (61%), M: D (66%), N: N (82%), P: N (66%), Q: N (66%), R: N (61%), S: N (87%), V: N (72%), W: D (71%), Y: N (53%),
Predicted by PROVEAN:	A: N, C: N, D: N, E: N, F: N, G: N, H: N, I: N, K: N, L: N, M: N, N: N, P: N, Q: N, R: N, S: N, V: N, W: N, Y: N,

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[hide] ABCA4 sequence variants in Chinese patients with a... Ophthalmologica. 2003 Mar-Apr;217(2):111-4. Baum L, Chan WM, Li WY, Lam DS, Wang PB, Pang CP
ABCA4 sequence variants in Chinese patients with age-related macular degeneration or Stargardt's disease.
Ophthalmologica. 2003 Mar-Apr;217(2):111-4., [PMID:12592048]

Abstract [show]
ABCA4 gene sequence alterations cause Stargardt's disease (STGD) and may cause some age-related macular degeneration (AMD). We sought to shed light on these associations among Hong Kong Chinese by genotyping 140 AMD, 18 STGD and 95 normal control subjects for 15 ABCA4 exons which were reported to often contain AMD- or STGD-associated mutations. Sequence alterations R212H, T1428M, V1433I, T1572M, I2166M, IVS6-5T>G and IVS33+1G>T were found in AMD patients. T1428M and R2040X occurred in STGD patients. Control subjects displayed all the above missense alterations but no splicing or nonsense changes. Therefore, ABCA4 splicing mutations may be associated with a small proportion of AMD cases.

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3 Sequence alterations R212H, T1428M, V1433I, T1572M, I2166M, IVS6-5T1G and IVS33+1G1T were found in AMD patients. Login to comment
4 T1428M and R2040X occurred in STGD patients. Login to comment
18 ABCA4 protein or splice sequence alterations in AMD and normal controls Sequence change AMD (140) Normal (95) Reports R212H 1 (1%) 1 (1%) polymorphism [18, 24] IVS6-5T1G 1 (1%) 0 (0%) novel T1428M 18 (13%) 15 (16%) rare in AMD [15] or common polymorphism [17] V1433I 1 (1%) 1 (1%) 1/150 STGD families and 0/220 normal controls [14]; 1/182 AMD, 0/96 normal controls and 0/374 STGD [38]; not segregated with AMD in families [13] T1572M 1 (1%) 1 (1%) novel IVS33+1G1T 1 (1%) 0 (0%) novel I2166M 2 (1%) 1 (1%) novel Table 2. Login to comment
19 ABCA4 protein sequence alterations in STGD and normal controls STGD (18) Normal (95) Reports T1428M 2 (11%) 15 (16%) rare in AMD [15] or common polymorphism [17] R2040X 2 (11%) 0 (0%) novel, but nearby truncations in STGD [14] to explore the possible link between ABCA4 alterations and AMD in a previously unexamined ethnic group, we selected 15 exons which had been reported to contain a high proportion of the known ABCA4 sequence changes in STGD and AMD [13, 15, 17, 19, 21], and we examined these exon coding regions and their splice sites for sequence changes in 140 AMD, 18 STGD and 95 elderly normal control subjects who were all unrelated Hong Kong residents, as well as in family members of some patients. Login to comment
40 T1428M appears to be a polymorphism. Login to comment

[hide] Differential occurrence of mutations causative of ... Hum Mutat. 2002 Mar;19(3):189-208. Pang CP, Lam DS
Differential occurrence of mutations causative of eye diseases in the Chinese population.
Hum Mutat. 2002 Mar;19(3):189-208., [PMID:11857735]

Abstract [show]
Ethnic differences and geographic variations affect the frequencies and nature of human mutations. In the literature, descriptions of causative mutations of eye diseases in the Chinese population are few. In this paper we attempt to reveal molecular information on genetic eye diseases involving Chinese patients from published and unpublished works by us and other groups. Our studies on candidate genes of eye diseases in the Chinese population in Hong Kong include MYOC and TISR for primary open angle glaucoma, RHO and RP1 for retinitis pigmentosa, ABCA4 and APOE for age-related macular degeneration, RB1 for retinoblastoma, APC for familial adenomatous polyposis with congenital hypertrophy of retinal pigment epithelium, BIGH3/TGFBI for corneal dystrophies, PAX6 for aniridia and Reiger syndrome, CRYAA and CRYBB2 for cataracts, and mtDNA for Leber hereditary optic neuropathy. We have revealed novel mutations in most of these genes, and in RHO, RP1, RB1, BIGH3, and PAX6 we have reported mutations that contribute to better understanding of the functions and properties of the respective gene products. We showed absence of MYOC does not necessarily cause glaucoma. No disease causative mutations have been identified in MYOC or ABCA4. There are similarities in the patterns of sequence alterations and phenotype-genotype associations in comparison with other ethnic groups, while the MYOC, RB1, APC, and PAX6 genes have more Chinese-specific sequence alterations. Establishment of a mutation database specific for the Chinese is essential for identification of genetic markers with diagnostic, prognostic, or pharmacological values.

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166 T1428M, a rare sequence change in Caucasians, occurs in about 8% of Japanese patients [Kuroiwa et al., 1999]. Login to comment
180 One patient, a 53-year-old woman, had a heterozygous splice site alteration, IVS33+1G>T, and a heterozygous missense alteration, T1428M. Login to comment

[hide] Genotype-phenotype analysis of ABCR variants in ma... Invest Ophthalmol Vis Sci. 2002 Feb;43(2):466-73. Bernstein PS, Leppert M, Singh N, Dean M, Lewis RA, Lupski JR, Allikmets R, Seddon JM
Genotype-phenotype analysis of ABCR variants in macular degeneration probands and siblings.
Invest Ophthalmol Vis Sci. 2002 Feb;43(2):466-73., [PMID:11818392]

Abstract [show]
PURPOSE: Single-copy variants of the autosomal recessive Stargardt disease (STGD1) gene ABCR (ABCA4) have been shown to confer enhanced susceptibility to age-related macular degeneration (AMD). To investigate the role of ABCR alleles in AMD further, genotype-phenotype analysis was performed on siblings of patients with AMD who had known ABCR variants. This genetically related population provides a cohort of subjects with similar age and ethnic background for genotype-phenotype comparison to the original probands. METHODS: All available siblings of 26 probands carrying probable disease-associated ABCR variants were examined clinically. Blood samples were collected from these siblings for genotype analysis to search for the ABCR variant alleles corresponding to the isofamilial proband. RESULTS: Nineteen of 33 siblings from 15 families carried the respective proband's variant ABCR allele. Some families exhibited concordance of ABCR alleles with macular degeneration phenotype, but others did not. Exudative AMD was uncommon among both probands and siblings. CONCLUSIONS: Although population studies have indicated that some ABCR variant alleles may enhance susceptibility to AMD, investigation of the extent of ABCR involvement by kindred analysis is complicated by a plethora of environmental and other hereditary factors not investigated in the current study that may also play important roles.

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52 AMD Grade of Probands Carrying Heterozygous ABCR Variants ABCR Variant Grade 1 Grade 2 Grade 3 Grade 4 Grade 5 E471K 0 0 1 1 0 P940R* 0 0 0 1 0 T1428M 0 0 1 0 0 R1517S 0 0 0 1 0 I1562T 0 0 1 1 0 G1578R 0 0 1 0 0 5196ϩ1G3A 0 0 1 0 0 R1898H 0 0 0 1 0 G1961E 0 0 2 4 0 L1970F 0 0 1 0 0 6519⌬11bp 0 0 0 1 0 D2177N 0 1 3 3 0 6568⌬C 0 0 0 0 1 Data are number of probands at each grade. Login to comment

[hide] Cosegregation and functional analysis of mutant AB... Hum Mol Genet. 2001 Nov 1;10(23):2671-8. Shroyer NF, Lewis RA, Yatsenko AN, Wensel TG, Lupski JR
Cosegregation and functional analysis of mutant ABCR (ABCA4) alleles in families that manifest both Stargardt disease and age-related macular degeneration.
Hum Mol Genet. 2001 Nov 1;10(23):2671-8., [PMID:11726554]

Abstract [show]
Mutations in ABCR (ABCA4) have been reported to cause a spectrum of autosomal recessively inherited retinopathies, including Stargardt disease (STGD), cone-rod dystrophy and retinitis pigmentosa. Individuals heterozygous for ABCR mutations may be predisposed to develop the multifactorial disorder age-related macular degeneration (AMD). We hypothesized that some carriers of STGD alleles have an increased risk to develop AMD. We tested this hypothesis in a cohort of families that manifest both STGD and AMD. With a direct-sequencing mutation detection strategy, we found that AMD-affected relatives of STGD patients are more likely to be carriers of pathogenic STGD alleles than predicted based on chance alone. We further investigated the role of AMD-associated ABCR mutations by testing for expression and ATP-binding defects in an in vitro biochemical assay. We found that mutations associated with AMD have a range of assayable defects ranging from no detectable defect to apparent null alleles. Of the 21 missense ABCR mutations reported in patients with AMD, 16 (76%) show abnormalities in protein expression, ATP-binding or ATPase activity. We infer that carrier relatives of STGD patients are predisposed to develop AMD.

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116 To analyze the function of AMD-associated ABCR mutations, we characterized the effects of seven different missense mutations (D645N, T901A, T1428M, R1517S, I1562T, G1578R and L1970F) on protein expression and ATP binding. Login to comment

[hide] Simple and complex ABCR: genetic predisposition to... Am J Hum Genet. 2000 Oct;67(4):793-9. Epub 2000 Sep 1. Allikmets R
Simple and complex ABCR: genetic predisposition to retinal disease.
Am J Hum Genet. 2000 Oct;67(4):793-9. Epub 2000 Sep 1., [PMID:10970771]

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44 Another ABCR allele, T1428M, which is very rare in populations of European descent, is apparently frequent (~8%) in the Japanese general population (Kuroiwa et al. 1999). Login to comment

[hide] Molecular genetic analysis of ABCR gene in Japanes... Jpn J Ophthalmol. 2000 May-Jun;44(3):245-9. Fuse N, Suzuki T, Wada Y, Yoshida M, Shimura M, Abe T, Nakazawa M, Tamai M
Molecular genetic analysis of ABCR gene in Japanese dry form age-related macular degeneration.
Jpn J Ophthalmol. 2000 May-Jun;44(3):245-9., [PMID:10913642]

Abstract [show]
PURPOSE: To explore whether the mutation in the retina-specific ATP-binding cassette transporter (ABCR) gene, the Stargardt's disease gene, contributes to the prevalence of the dry form of age-related macular degeneration (dry AMD) in Japanese unrelated patients. METHODS: Twenty-five Japanese unrelated patients with dry AMD who were diagnosed by fluorescein angiography and indocyanine green angiography were chosen as the dry AMD group. None of these cases had apparent choroidal neovascularization. To detect the mutations in the ABCR gene, genomic DNA was extracted from leukocytes of peripheral blood, and 26 exons of the ABCR gene were amplified by polymerase chain reaction (PCR). All the PCR products were then directly sequenced. When a mutation was detected, the occurrence of a mutation was compared between these AMD patients and the control group. RESULTS: After direct sequencing, a point mutation in exon 29 was found in one of the 25 dry AMD patients. In addition, a polymorphism in exon 45 was found in two other patients, and three sequence variations in exon 23 were detected in all patients. The incidence in AMD patients in whom a mutation in exon 29 (4%) was detected was less than that in controls (5%). Screening of the intron-exon boundaries also led to the identification of intronic mutation in intron 33. CONCLUSION: In this study we found no relationship between allelic variation in the ABCR gene and the prevalence of dry AMD in Japanese unrelated patients.

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31 Mutations Found in ABCR* Gene in 26 Exons Examined in This Study Exon AMD† Stargardt`s Disease Exon AMD Stargardt`s Disease 11 E471K 29 T1428M 15 31 R1517S 16 G818E, G863A (D847H) 33 I1562T G1578R 17 34 N1614FS 18 35 19 V931M, 2884delC N965M, (R943Q) 36 5196ϩ1G→A 5041deL15 5196ϩ2T→C 20 40 R1898H R1898H 21 A1028V 42 G1961E G1961E 22 3211insGT, V1072A E1087K 43 L1970F 6006ϩ1G→T 23 R1129L 44 L2027F, R2038W (I2023I) 24 45 V2050L, R2077W (I2083I) 25 46 R2106C (V2094V) 27 48 6519⌬11bp D2177N 6568⌬C 6519⌬11bp 6709insG *ABCR: ATP-binding cassette transporter. Login to comment
55 Sequence Variations, Mutation, and Polymorphism in ABCR* Gene Detected in This Study Alteration Base Change Dry AMD† (n ϭ 25) Controls (n ϭ 40) P1116S CCC→TCC (homozygote) 25 (100%) 40 (100%) H1125L CAC→CTC (homozygote) 25 (100%) 40 (100%) Q1126L CAA→CTT (homozygote) 25 (100%) 40 (100%) T1428M ACG→ATG (heterozygote) 1 (4%) 2 (5%) Polymorphism I2083I ATC→ATT (heterozygote) 2 (8%) 0 (0%) Intron basechange Intron 33: 4773ϩ48C→T (heterozygote) 4 (16%) 4773ϩ48C→T (homozygote) 2 (8%) *ABCR: ATP-binding cassette transporter. Login to comment
58 Our results showed that the incidence of the T1428M mutation was 4% in Japanese dry AMD patients, but this mutation was found more frequently (5%) in the controls. Login to comment

[hide] Analysis of the Stargardt disease gene (ABCR) in a... Ophthalmology. 1999 Aug;106(8):1531-6. De La Paz MA, Guy VK, Abou-Donia S, Heinis R, Bracken B, Vance JM, Gilbert JR, Gass JD, Haines JL, Pericak-Vance MA
Analysis of the Stargardt disease gene (ABCR) in age-related macular degeneration.
Ophthalmology. 1999 Aug;106(8):1531-6., [PMID:10442900]

Abstract [show]
PURPOSE: Age-related macular degeneration (AMD) is a complex genetic disorder and the leading cause of severe vision loss in the elderly. The Stargardt disease gene (ABCR) has been proposed as a major genetic risk factor in AMD. The purpose of this study was to evaluate the authors' AMD population for the specific ABCR variants proposed previously as genetic risk factors for AMD. METHODS: The authors screened their AMD population (159 familial cases from 112 multiplex families and 53 sporadic cases) and 56 racially matched individuals with no known history of AMD from the same clinic population for evidence of the ABCR variants. Grading of disease severity was performed according to a standard protocol. Patients with extensive intermediate drusen or large soft drusen, drusenoid retinal pigment epithelial (RPE) detachments, geographic atrophy of the RPE, or evidence of exudative maculopathy were considered affected. Analysis for variants was performed by polymerase chain reaction amplification of individual exons of the ABCR gene with flanking primers and a combination of single-strand conformation polymorphism, heteroduplex analysis, and high-performance liquid chromatography. All abnormal conformers detected using these techniques were characterized by direct sequencing. RESULTS: The authors identified only two of the previously reported variants in their study population. Both variants occurred in sporadic cases, and none was found in familial cases or the randomly selected population. In addition, the authors identified several newly described polymorphisms and variants in both the AMD and control populations. CONCLUSIONS: Based on these initial findings, the authors suggest that ABCR is not a major genetic risk factor for AMD in their study population. Additional genetic studies are needed to more fully evaluate the role of ABCR in AMD.

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107 Number of Age-related Macular Degeneration (AMD) Cases with Variants* Mutation Duke (n ‫؍‬ 169)† D2177N 2 (1.2%) E471K 0 R1129L 0 T1428M 0 R1517S 0 I1562T 0 G1578R 0 5169 ϩ 1G 3 A 0 R1898H 0 G1961E 0 L1970F 0 6519⌬11bp 0 6568⌬C 0 Total 2 (1.2%) * Variants considered to be associated with the genetic etiology of AMD by Allikmets et al.31 † Independent cases are determined by counting 1 familial AMD case from each of the 112 families and adding the 57 sporadic AMD cases, for a total of 169 cases. Login to comment

[hide] Mutation of the Stargardt disease gene (ABCR) in a... Science. 1997 Sep 19;277(5333):1805-7. Allikmets R, Shroyer NF, Singh N, Seddon JM, Lewis RA, Bernstein PS, Peiffer A, Zabriskie NA, Li Y, Hutchinson A, Dean M, Lupski JR, Leppert M
Mutation of the Stargardt disease gene (ABCR) in age-related macular degeneration.
Science. 1997 Sep 19;277(5333):1805-7., [PMID:9295268]

Abstract [show]
Age-related macular degeneration (AMD) is the leading cause of severe central visual impairment among the elderly and is associated both with environmental factors such as smoking and with genetic factors. Here, 167 unrelated AMD patients were screened for alterations in ABCR, a gene that encodes a retinal rod photoreceptor protein and is defective in Stargardt disease, a common hereditary form of macular dystrophy. Thirteen different AMD-associated alterations, both deletions and amino acid substitutions, were found in one allele of ABCR in 26 patients (16%). Identification of ABCR alterations will permit presymptomatic testing of high-risk individuals and may lead to earlier diagnosis of AMD and to new strategies for prevention and therapy.

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99 Mutation AMD (n ϭ167) STGD (n ϭ 98) General population (n ϭ 220) E471K 2 (1.2%) NA 0 (0%) R1129L 1 (0.6%) 0 (0%)* 0 (0%) T1428M 1 (0.6%) 0 (0%) 0 (0%) R1517S 1 (0.6%) 0 (0%) 0 (0%) I1562T 2 (1.2%) 0 (0%) 0 (0%) G1578R 1 (0.6%) 0 (0%) 0 (0%) 5196ϩ1G 3 A 1 (0.6%) 0 (0%) 0 (0%) R1898H 1 (0.6%) 4 (4%) 0 (0%) G1961E 6 (3.6%) 8 (8%) 0 (0%) L1970F 1 (0.6%) 0 (0%) 0 (0%) 6519⌬11bp 1 (0.6%)† 1 (1%)† 0 (0%) D2177N 7 (4.2%) 0 (0%) 1 (0.45%) 6568⌬C 1 (0.6%) 0 (0%) 0 (0%) Totals 26 (16%) 13 (13%) 1 (0.45%) *A substitution to a different amino acid (R1129C) was detected in one STGD1 patient. Login to comment
96 Mutation AMD (n 5167) STGD (n 5 98) General population (n 5 220) E471K 2 (1.2%) NA 0 (0%) R1129L 1 (0.6%) 0 (0%)* 0 (0%) T1428M 1 (0.6%) 0 (0%) 0 (0%) R1517S 1 (0.6%) 0 (0%) 0 (0%) I1562T 2 (1.2%) 0 (0%) 0 (0%) G1578R 1 (0.6%) 0 (0%) 0 (0%) 519611G 3 A 1 (0.6%) 0 (0%) 0 (0%) R1898H 1 (0.6%) 4 (4%) 0 (0%) G1961E 6 (3.6%) 8 (8%) 0 (0%) L1970F 1 (0.6%) 0 (0%) 0 (0%) 6519D11bp 1 (0.6%)ߤ 1 (1%)ߤ 0 (0%) D2177N 7 (4.2%) 0 (0%) 1 (0.45%) 6568DC 1 (0.6%) 0 (0%) 0 (0%) Totals 26 (16%) 13 (13%) 1 (0.45%) *A substitution to a different amino acid (R1129C) was detected in one STGD1 patient. Login to comment

[hide] Analysis of the ABCA4 gene by next-generation sequ... Invest Ophthalmol Vis Sci. 2011 Oct 31;52(11):8479-87. doi: 10.1167/iovs.11-8182. Zernant J, Schubert C, Im KM, Burke T, Brown CM, Fishman GA, Tsang SH, Gouras P, Dean M, Allikmets R
Analysis of the ABCA4 gene by next-generation sequencing.
Invest Ophthalmol Vis Sci. 2011 Oct 31;52(11):8479-87. doi: 10.1167/iovs.11-8182., [PMID:21911583]

Abstract [show]
PURPOSE: To find all possible disease-associated variants in coding sequences of the ABCA4 gene in a large cohort of patients diagnosed with ABCA4-associated diseases. METHODS: One hundred sixty-eight patients who had been clinically diagnosed with Stargardt disease, cone-rod dystrophy, and other ABCA4-associated phenotypes were prescreened for mutations in ABCA4 with the ABCA4 microarray, resulting in finding 1 of 2 expected mutations in 111 patients and 0 of 2 mutations in 57 patients. The next-generation sequencing (NGS) strategy was applied to these patients to sequence the entire coding region and the splice sites of the ABCA4 gene. Identified new variants were confirmed or rejected by Sanger sequencing and analyzed for possible pathogenicity by in silico programs and, where possible, by segregation analyses. RESULTS: Sequencing was successful in 159 of 168 patients and identified the second disease-associated allele in 49 of 103 (~48%) of patients with one previously identified mutation. Among those with no mutations, both disease-associated alleles were detected in 4 of 56 patients, and one mutation was detected in 10 of 56 patients. The authors detected a total of 57 previously unknown, possibly pathogenic, variants: 29 missense, 4 nonsense, 9 small deletions and 15 splice-site-altering variants. Of these, 55 variants were deemed pathogenic by a combination of predictive methods and segregation analyses. CONCLUSIONS: Many mutations in the coding sequences of the ABCA4 gene are still unknown, and many possibly reside in noncoding regions of the ABCA4 locus. Although the ABCA4 array remains a good first-pass screening option, the NGS platform is a time- and cost-efficient tool for screening large cohorts.

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68 (C) An example of a pedigree segregating a complex allele in which one variant (c.2894Ab0e;G, p.N965S) causes disease and the other, c.4283Cb0e;T, p.T1428M, is a benign polymorphism, although it was originally described as a rare mutation in patients of European descent. Login to comment

[hide] Clinical and molecular analysis of Stargardt disea... Am J Ophthalmol. 2013 Sep;156(3):487-501.e1. doi: 10.1016/j.ajo.2013.05.003. Fujinami K, Sergouniotis PI, Davidson AE, Wright G, Chana RK, Tsunoda K, Tsubota K, Egan CA, Robson AG, Moore AT, Holder GE, Michaelides M, Webster AR
Clinical and molecular analysis of Stargardt disease with preserved foveal structure and function.
Am J Ophthalmol. 2013 Sep;156(3):487-501.e1. doi: 10.1016/j.ajo.2013.05.003., [PMID:23953153]

Abstract [show]
PURPOSE: To describe a cohort of patients with Stargardt disease who show a foveal-sparing phenotype. DESIGN: Retrospective case series. METHODS: The foveal-sparing phenotype was defined as foveal preservation on autofluorescence imaging, despite a retinopathy otherwise consistent with Stargardt disease. Forty such individuals were ascertained and a full ophthalmic examination was undertaken. Following mutation screening of ABCA4, the molecular findings were compared with those of patients with Stargardt disease but no foveal sparing. RESULTS: The median age of onset and age at examination of 40 patients with the foveal-sparing phenotype were 43.5 and 46.5 years. The median logMAR visual acuity was 0.18. Twenty-two patients (22/40, 55%) had patchy parafoveal atrophy and flecks; 8 (20%) had numerous flecks at the posterior pole without atrophy; 7 (17.5%) had mottled retinal pigment epithelial changes; 2 (5%) had multiple atrophic lesions, extending beyond the arcades; and 1 (2.5%) had a bull's-eye appearance. The median central foveal thickness assessed with spectral-domain optical coherence tomographic images was 183.0 mum (n = 33), with outer retinal tubulation observed in 15 (45%). Twenty-two of 33 subjects (67%) had electrophysiological evidence of macular dysfunction without generalized retinal dysfunction. Disease-causing variants were found in 31 patients (31/40, 78%). There was a higher prevalence of the variant p.Arg2030Gln in the cohort with foveal sparing compared to the group with foveal atrophy (6.45% vs 1.07%). CONCLUSIONS: The distinct clinical and molecular characteristics of patients with the foveal-sparing phenotype are described. The presence of 2 distinct phenotypes of Stargardt disease (foveal sparing and foveal atrophy) suggests that there may be more than 1 disease mechanism in ABCA4 retinopathy.

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141 Allele Frequencies of 72 ABCA4 Variants Identified in a Comparison Groupa With the Typical Stargardt Disease (140 Patients Without Evidence of Foveal Sparing on Autofluorescence Imaging) Exon Nucleotide Substitution and Amino Acid Change Number of Alleles Allele Frequency 2 c.71G>A, p.Arg24His 1 0.36% 2 c.161G>A, p.Cys54Tyr 3 1.07% 3 c.223T>G, p.Cys75Gly 1 0.36% 5 c.455G>A, p.Arg152Gln 1 0.36% 5 c.454C>T, p.Arg152* 1 0.36% 5 c.466 A>G, p.Ile156Val 2 0.71% 6 c.634C>T, p. Arg212Cys 3 1.07% 6 c.656G>C, p.Arg219Thr 1 0.36% 6 c.666_678delAAAGACGGTGCGC, p.Lys223_Arg226delfs 2 0.71% 6 c.768G>T, Splicing site 4 1.42% 8 c.1037A>C, p.Lys346Thr 1 0.36% 10 c.1222C>T, p.Arg408* 3 1.07% 12 c.1622T>C, p.Leu541Pro 2 0.71% 12 c.1648 G>T, p.Gly550* 1 0.36% 13 c.1804C>T, p.Arg602Trp 1 0.36% 13 c.1817G>A, p.Gly606Asp 1 0.36% 13 c.1922G>C, p.Cys641Ser 1 0.36% Int 13 c.1937&#fe;1G>A, Splicing site 2 0.71% 14 c.1957C>T, p.Arg653Cys 2 0.71% 17 c.2588G>C, p.Gly863Ala 19 6.79% 18 c.2701A>G, p.Thr901Ala 1 0.36% 19 c.2791G>A, p.Val931Met 2 0.71% 19 c.2894A>G, p.Asn965Ser 1 0.36% 20 c.2966T>C, p.Vla989Ala 3 1.07% 20 c.2971G>C, p.Gly991Arg 2 0.71% 21 c.3056C>T, p.Thr1019Met 1 0.36% 21 c.3113C>T, p.Ala1038Val 3 1.07% 21 c.3064G>A, p.Glu1022Lys 2 0.71% 22 c.3211_3212insGT, p.Ser1071Cysfs 6 2.14% 22 c.3259G>A, p.Glu1087Lys 4 1.43% 22 c.3292C>T, p.Arg1098Cys 1 0.36% 22 c.3322C>T, p.Arg1108Cys 5 1.79% 22 c.3323G>A, p.Arg1108His 1 0.36% 23 c.3364G>A, p.Glu1122Lys 1 0.36% 23 c.3386G>A, p.Arg1129His 1 0.36% 24 c.3602T>G, p.Leu1201Arg 3 1.07% 27 c.3898C>T, p.Arg1300* 2 0.71% 28 c.4139C>T, p.Pro1380Leu 14 5.00% 28 c.4222T>C, p.Trp1408Arg 1 0.36% 28 c.4234C>T, p.Gly1412* 1 0.36% 28 c.4253&#fe;5G>T, Splice site 1 0.36% 28 c.4253&#fe;4C>T, Splice site 1 0.36% 29 c.4283C>T, p.Thr1428Met 1 0.36% 29 c.4319T>C, p.Phe1440Ser 1 0.36% 29 c.4462T>C, p.Cys1488Arg 1 0.36% 30 c.4469G>A, p.Cys1490Tyr 5 1.79% 30 c.4537_4538insC, p.Gly1513Profs 1 0.36% 31 c.4577C>T, p.Thr1526Met 2 0.71% 33 c.4715C>T, p.Thr1572Met 1 0.36% Continued on next page TABLE 3. Login to comment

[hide] ABCA4 gene screening by next-generation sequencing... Invest Ophthalmol Vis Sci. 2013 Oct 11;54(10):6662-74. doi: 10.1167/iovs.13-12570. Fujinami K, Zernant J, Chana RK, Wright GA, Tsunoda K, Ozawa Y, Tsubota K, Webster AR, Moore AT, Allikmets R, Michaelides M
ABCA4 gene screening by next-generation sequencing in a British cohort.
Invest Ophthalmol Vis Sci. 2013 Oct 11;54(10):6662-74. doi: 10.1167/iovs.13-12570., [PMID:23982839]

Abstract [show]
PURPOSE: We applied a recently reported next-generation sequencing (NGS) strategy for screening the ABCA4 gene in a British cohort with ABCA4-associated disease and report novel mutations. METHODS: We identified 79 patients with a clinical diagnosis of ABCA4-associated disease who had a single variant identified by the ABCA4 microarray. Comprehensive phenotypic data were obtained, and the NGS strategy was applied to identify the second allele by means of sequencing the entire coding region and adjacent intronic sequences of the ABCA4 gene. Identified variants were confirmed by Sanger sequencing and assessed for pathogenicity by in silico analysis. RESULTS: Of the 42 variants detected by prescreening with the microarray, in silico analysis suggested that 34, found in 66 subjects, were disease-causing and 8, found in 13 subjects, were benign variants. We detected 42 variants by NGS, of which 39 were classified as disease-causing. Of these 39 variants, 31 were novel, including 16 missense, 7 splice-site-altering, 4 nonsense, 1 in-frame deletion, and 3 frameshift variants. Two or more disease-causing variants were confirmed in 37 (47%) of 79 patients, one disease-causing variant in 36 (46%) subjects, and no disease-causing variant in 6 (7%) individuals. CONCLUSIONS: Application of the NGS platform for ABCA4 screening enabled detection of the second disease-associated allele in approximately half of the patients in a British cohort where one mutation had been detected with the arrayed primer extension (APEX) array. The time- and cost-efficient NGS strategy is useful in screening large cohorts, which will be increasingly valuable with the advent of ABCA4-directed therapies.

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56 40 c.4926C>G p.S1642R DC c.5041_5055del GTGGTTGCCATCTGC p.V1681_C1685del DC 2 41 c.4956T>G p.Y1652* DC 1 42 c.5018&#fe;2T>C Splice site DC 1 43 c.5461-10T>C DC c.6385A>G p.S2129G PDC 2 44 c.5461-10T>C DC 1 45 c.5461-10T>C DC 1 46 c.5461-10T>C DC 1 47 c.5461-10T>C DC 1 48 c.5461-10T>C DC 1 49 c.5461-10T>C DC 1 50 c.5461-10T>C DC 1 51 c.5585-1G>A Splice site DC 1 52 c.5714&#fe;5G>A Splice site DC c.6209C>G p.T2070R DC 2 53 c.5882G>A p.G1961E DC c.2686A>G p.K896E B 1 54 c.5882G>A p.G1961E DC c.3050&#fe;1G>C Splice site DC 2 55 c.5882G>A p.G1961E DC c.3392delC/3393C>G p.A1131Gfs DC 2 56 c.5882G>A p.G1961E DC c.4539&#fe;2T>G Splice site DC 2 57 c.5882G>A p.G1961E DC c.4552A>C p.S1518R DC 2 58 c.5882G>A p.G1961E DC c.5899-2delA Splice site DC 2 59 c.5882G>A p.G1961E DC 1 60 c.6079C>T p.L2027F DC c.1906C>T p.Q636* DC 2 61 c.6079C>T p.L2027F DC c.3322C>T p.R1108C DC 2 Allele 2 (p.R1108C) was APEX-false-negative 62 c.6079C>T p.L2027F DC c.3370G>T p.D1124Y DC 2 63 c.6079C>T p.L2027F DC 1 64 c.6089G>A p.R2030Q DC c.4326C>A p.N1442K DC 2 65 c.6445C>T p.R2149* DC 1 66 c.6709A>C p.T2237P DC c.5899-3_5899-2delTA Splice site DC 2 67 c.2971G>C p.G991R B c.4538A>G p.Q1513R DC 1 68 c.3602T>G p.L1201R B c.1749G>C p.K583N DC 1 69 c.3602T>G p.L1201R B c.1982_1983insG p.A662fs DC 1 70 c.3602T>G p.L1201R B c.2972G>T p.G991V DC 1 71 c.4685T>C p.I1562T B c.3289A>T p.R1097* DC 1 72 c.6320G>A p.R2107H B c.2510T>C p.L837P DC 1 73 c.6320G>A p.R2107H B c.4352&#fe;1G>A Splice site DC 1 74 c.2701A>G p.T901A B 0 75 c.3602T>G p.L1201R B 0 76 c.4283C>T p.T1428M B 0 77 c.466A>G p.I156V B 0 78 c.466A>G p.I156V B 0 79 c.4715C>T p.T1572M B 0 Putative novel variants are shown in italics. Login to comment
62 Hum Var Score (0-1) Site Wt CV Mt CV CV % Variation 3 c.161G>A p.C54Y 1 1 [ [ Lewis RA, et al. 11 Tol. 0.11 PRD 0.994 No change 1/13006 db SNP (rs150774447) 3 c.223T>G p.C75G 1 2 [ [ Lewis RA, et al. 11 Del. NA POD 0.603 No change ND 5 c.466A>G p.I156V 2 77, 78 [ [ Papaioannou M, et al. 16 Tol. 0.46 B 0.003 No change 16/13006 db SNP (rs112467008) Benign 6 c.655A>T p.R219* 1 11 [ Xi Q, et al. 27 ND 6 c.740A>C p.N247T 1 3 [ [ APEX Del. NA B 0.135 No change ND 6 c.768G>T Splice site 1 4 [ [ Klevering BJ, et al. 22 Tol. 0.56 NA Don. 70.4 58 Site broken (17.51) ND 9 c.1222C>T p.R408* 1 5 [ [ Webster AR, et al. 7 ND 12 c.1726G>C p.D576H 1 36 [ Downs K, et al. 25 POD 0.688 Acc. 68.1 39.1 Site broken (42.54) 1/13006 13 c.1804C>T p.R602W 1 6 [ [ Lewis RA, et al. 11 Del. 0.00 B 0.129 No change ND db SNP (rs 6179409) 13 c.1805G>A p.R602Q 1 7 [ [ Webster AR, et al. 7 Del. 0.04 PRD 0.513 Acc. 48.9 77.9 New site (&#fe;59.14) 2/13006 db SNP (rs61749410) 13 c.1906C>T p.Q636* 3 12, 13, 60 [ Zernant J, et al. 5 No change 1/13006 db SNP (rs145961131) 13 c.1922G>C p.C641S 1 8 [ [ Stenirri S, et al. 24 Del. 0.00 No change ND db SNP (rs61749416) 14 c.1957C>T p.R653C 2 9, 10 [ [ Rivera A, et al. 17 Del. 0.00 PRD 0.999 No change ND db SNP (rs61749420) 17 c.2588G>C p.G863A/ p.DelG863 5 11, 12, 13, 14, 15 [ [ Lewis RA, et al. 11 / Maugeri A, et al. 29 Del. 0.00 PRD 0.996 No change 68/13006 db SNP (rs76157638) 18 c.2701A>G p.T901A 1 74 [ [ APEX Tol. 0.82 B 0.008 23/13006 db SNP (rs139655975) Benign 19 c.2894A>G p.N965S 1 16 [ [ Lewis RA, et al. 11 Del. 0.03 PRD 0.981 Acc. 53.4 82.3 New site (&#fe;54.26) ND db SNP (rs201471607) 20 c.2971G>C p.G991R 1 67 [ [ Yatsenko AN, et al. 13 Del. 0.02 PRD 0.999 No change 28/13006 db SNP (rs147484266) Benign 22 c.3064G>A p.E1022K 2 17, 18 [ [ Webster AR, et al. 7 Del. 0.00 PRD 1.000 No change ND db SNP (rs61749459) 22 c.3208_3209insGT p.S1071fs 5 19, 20, 21, 22, 25 [ [ APEX ND False-negative in APEX in patient 25 22 c.3292C>T p.R1098C 1 23 [ [ Rivera A, et al. 17 Del. NA PRD 0.999 No change ND 22 c.3322C>T p.R1108C 3 16, 24, 61 [ [ Rozet JM, et al. 10 Del. 0.00 PRD 0.986 No change 1/13006 db SNP (rs61750120) False-negative in APEX in patients 16 and 61 23 c.3386G>A p.R1129H 1 25 [ Zernant J, et al. 5 PRD 0.989 No change ND False-negative in NGS in patient 25 24 c.3602T>G p.L1201R 4 72, 73, 74, 79 [ [ Lewis RA, et al. 11 Tol. 0.37 B 0.052 Don. 61.3 73.7 New site (20.08) 416/13006 db SNP (rs61750126) Benign 28 c.4139C>T p.P1380L 7 30, 31, 32, 33, 34, 35, 36 [ [ Lewis RA, et al. 11 Del. 0.01 B 0.377 No change 2/13006 db SNP (rs61750130) 28 c.4234C>T p.Q1412* 1 33 [ [ Rivera A, et al. 17 ND db SNP (rs61750137) 29 c.4283C>T p.T1428M 1 76 [ [ APEX Tol. 0.15 B 0.010 No change 2/13006 db SNP (rs1800549) Benign 29 c.4319T>C p.F1440S 1 34 [ [ Lewis RA, et al. 11 Del. 0.00 POD 0.744 No change ND dbSNP (rs61750141) 29 c.4326C>A p.N1442K 1 64 [ Zernant J, et al. 5 Tol. NA POD 0.374 No change ND 29 c.4328G>A p.R1443H 1 35 [ [ Rivera A, et al. 17 Del. 0.02 PRD 0.999 No change 1/13006 dbSNP (rs61750142) IVS29 c.4352&#fe;1G>A Splice site 1 73 [ Zernant J, et al. 5 Don. 82.3 55.4 WT site broken (32.62) ND 30 c.4469G>A p.C1490Y 2 36, 37 [ [ Lewis RA, et al. 11 Del. 0.00 PRD 0.994 No change ND dbSNP (rs61751402) 30 c.4538A>G p.Q1513R 1 67 [ Webster AR, et al. 7 Tol. NA Benign 0.043 Acc. 91.7 62.8 Site broken (31.55) ND T ABLE 3. Continued Exon/ IVS Nucleotide Substitution Protein Change/ Effect N of Alleles Identified Pt Method Previous Report SIFT Polyphen 2 HSF Matrix Allele Freq. by EVS Reference Comment APEX NGS Pred. Tol. Index (0-1) Pred. Login to comment

[hide] Molecular diagnosis of putative Stargardt disease ... PLoS One. 2014 Apr 24;9(4):e95528. doi: 10.1371/journal.pone.0095528. eCollection 2014. Zhang X, Ge X, Shi W, Huang P, Min Q, Li M, Yu X, Wu Y, Zhao G, Tong Y, Jin ZB, Qu J, Gu F
Molecular diagnosis of putative Stargardt disease by capture next generation sequencing.
PLoS One. 2014 Apr 24;9(4):e95528. doi: 10.1371/journal.pone.0095528. eCollection 2014., [PMID:24763286]

Abstract [show]
Stargardt Disease (STGD) is the commonest genetic form of juvenile or early adult onset macular degeneration, which is a genetically heterogeneous disease. Molecular diagnosis of STGD remains a challenge in a significant proportion of cases. To address this, seven patients from five putative STGD families were recruited. We performed capture next generation sequencing (CNGS) of the probands and searched for potentially disease-causing genetic variants in previously identified retinal or macular dystrophy genes. Seven disease-causing mutations in ABCA4 and two in PROM1 were identified by CNGS, which provides a confident genetic diagnosis in these five families. We also provided a genetic basis to explain the differences among putative STGD due to various mutations in different genes. Meanwhile, we show for the first time that compound heterozygous mutations in PROM1 gene could cause cone-rod dystrophy. Our findings support the enormous potential of CNGS in putative STGD molecular diagnosis.

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142 One previous study of STGD in the Chinese population, screened part of ABCA4 coding sequence (15 exons) and identified two relatively common mutations: T1428M and R2040X [21]. Login to comment