ABCC8 p.Arg74Gln
| Predicted by SNAP2: | A: N (53%), C: D (63%), D: D (80%), E: N (53%), F: D (63%), G: D (95%), H: N (82%), I: N (57%), K: N (87%), L: N (78%), M: N (57%), N: N (61%), P: N (53%), Q: N (66%), S: N (61%), T: N (61%), V: N (57%), W: D (91%), Y: D (75%), |
| 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] ABCC8 and KCNJ11 molecular spectrum of 109 patient... J Med Genet. 2010 Nov;47(11):752-9. Epub 2010 Aug 3. Bellanne-Chantelot C, Saint-Martin C, Ribeiro MJ, Vaury C, Verkarre V, Arnoux JB, Valayannopoulos V, Gobrecht S, Sempoux C, Rahier J, Fournet JC, Jaubert F, Aigrain Y, Nihoul-Fekete C, de Lonlay P
ABCC8 and KCNJ11 molecular spectrum of 109 patients with diazoxide-unresponsive congenital hyperinsulinism.
J Med Genet. 2010 Nov;47(11):752-9. Epub 2010 Aug 3., [PMID:20685672]
Abstract [show]
BACKGROUND: Congenital hyperinsulinism (CHI) is characterised by an over secretion of insulin by the pancreatic beta-cells. This condition is mostly caused by mutations in ABCC8 or KCNJ11 genes encoding the SUR1 and KIR6.2 subunits of the ATP-sensitive potassium (K(ATP)) channel. CHI patients are classified according to their responsiveness to diazoxide and to their histopathological diagnosis (either focal, diffuse or atypical forms). Here, we raise the benefits/limits of the genetic diagnosis in the clinical management of CHI patients. METHODS: ABCC8/KCNJ11 mutational spectrum was established in 109 diazoxide-unresponsive CHI patients for whom an appropriate clinical management is essential to prevent brain damage. Relationships between genotype and radiopathological diagnosis were analysed. RESULTS: ABCC8 or KCNJ11 defects were found in 82% of the CHI cases. All patients with a focal form were associated with a single K(ATP) channel molecular event. In contrast, patients with diffuse forms were genetically more heterogeneous: 47% were associated with recessively inherited mutations, 34% carried a single heterozygous mutation and 19% had no mutation. There appeared to be a predominance of paternally inherited mutations in patients diagnosed with a diffuse form and carrying a sole K(ATP) channel mutation. CONCLUSIONS: The identification of recessively inherited mutations related to severe and diffuse forms of CHI provides an informative genetic diagnosis and allows prenatal diagnosis. In contrast, in patients carrying a single K(ATP) channel mutation, genetic analysis should be confronted with the PET imaging to categorise patients as focal or diffuse forms in order to get the appropriate therapeutic management.
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102 J Med Genet 2010;47:752e759. doi:10.1136/jmg.2009.075416 Original article Table 2 Characteristics of ABCC8 and KCNJ11 mutations Gene Location Nucleotide sequence change Protein effect Occurrence Histopathological / radiological diagnosisz Genetic Statusy References ABCC8 Exon 1 c.62T/A p.Val21Asp 1 DPVS hmz Sandal et al, 200944 ABCC8 Exon 2 c.221G/A p.Arg74Gln 1 DH c-htz Flanagan et al, 200817 ABCC8 Exon 2 c.259_268del p.Cys87fs 1 FH This report ABCC8 Exon 3 c.403C/G p.Leu135Val 1 DH c-htz This report ABCC8 Exon 4 c.428G/A p.Trp143X 3 FH, DH, DPET c-htz (x2) This report ABCC8 Exon 4 c.496C/T p.Gln166X 1 DPET c-htz This report ABCC8 Exon 4 c.536A/G p.Tyr179Cys 2 FH, DPET hmz Damaj et al, 200845 ABCC8 Intron 4 c.580-1G/C p.?
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ABCC8 p.Arg74Gln 20685672:102:355
status: NEW105 3 FH (x2), DPET htzP Flanagan et al, 2008 ABCC8 Exon 12 c.1732_1746dup15 p.Ala578_Leu582dup5 1 DPET htzP Flanagan et al, 200817 ABCC8 Exon 12 c.1738C/T p.Leu580Phe 1 DPET hmz This report ABCC8 Exon 12 c.1792C/T p.Arg598X 2 FH, DH c-htz Flanagan et al, 200817 ABCC8 Intron 13 c.1923+5G/T p.?
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ABCC8 p.Arg74Gln 20685672:105:322
status: NEW[hide] Genetic heterogeneity in familial hyperinsulinism. Hum Mol Genet. 1998 Jul;7(7):1119-28. Nestorowicz A, Glaser B, Wilson BA, Shyng SL, Nichols CG, Stanley CA, Thornton PS, Permutt MA
Genetic heterogeneity in familial hyperinsulinism.
Hum Mol Genet. 1998 Jul;7(7):1119-28., [PMID:9618169]
Abstract [show]
Familial hyperinsulinism (HI) is a disorder characterized by dysregulation of insulin secretion and profound hypoglycemia. Mutations in both the Kir6.2 and sulfonylurea receptor (SUR1) genes have been associated with the autosomal recessive form of this disorder. In this study, the spectrum and frequency of SUR1 mutations in HI and their significance to clinical manifestations of the disease were investigated by screening 45 HI probands of various ethnic origins for mutations in the SUR1 gene. Single-strand conformation polymorphism (SSCP) and nucleotide sequence analyses of genomic DNA revealed a total of 17 novel and three previously described mutations in SUR1 . The novel mutations comprised one nonsense and 10 missense mutations, two deletions, three mutations in consensus splice-site sequences and an in-frame insertion of six nucleotides. One mutation occurred in the first nucleotide binding domain (NBF-1) of the SUR1 molecule and another eight mutations were located in the second nucleotide binding domain (NBF-2), including two at highly conserved amino acid residues within the Walker A sequence motif. The majority of the remaining mutations was distributed throughout the three putative transmembrane domains of the SUR1 protein. With the exception of the 3993-9G-->A mutation, which was detected on 4.5% (4/88) disease chromosomes, allelic frequencies for the identified mutations varied between 1.1 and 2.3% for HI chromosomes, indicating that each mutation was rare within the patient cohort. The clinical manifestations of HI in those patients homozygous for mutations in the SUR1 gene are described. In contrast with the allelic homogeneity of HI previously described in Ashkenazi Jewish patients, these findings suggest that a large degree of allelic heterogeneity at the SUR1 locus exists in non-Ashkenazi HI patients. These data have important implications for genetic counseling and prenatal diagnosis of HI, and also provide a basis to further elucidate the molecular mechanisms underlying the pathophysiology of this disease.
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63 Mutations within the SUR1 gene Patient Exon or intron Nucleotide changea Codona predicted effect Domainb Restriction site change Frequency (%) HI chromosomes (n = 88) Segregation demonstrated Frequency 200 normal chromosomes A1 exon 2 221G→A R74Q Tm PstI 1 (1.1%) NA 0 B2d exon3 375C→G H125Q Tm DdeIc 1 (1.1%) NA 0 C3e exon 4 563A→G N188S Tm TspRI 1 (1.1%) yes 0 D4 exon 6 949delC 317fs/ter Tm Bsp1286I 1 (1.1%) yes 0 E5 exon 8 1216A→G N406D Tm XcmI 1 (1.1%) NA 0 F6f intron 10 1630+1G→T aberrant splicing Tm BsrI 2 (2.3%) yes 0 G7 exon 12 1773C→G F591L Tm BsoF1 1 (1.1%) no 0 H8 exon 13 1893delT 631fs/ter Tm BstNI 1 (1.1%) yes 0 F6f intron 15 2117-1G→A aberrant splicing NBF-1 PstI 1 (1.1%) yes 0 I9 exon 24 2860C→T Q954X - BstNI 1 (1.1%) yes 0 J10g exon 28 3416C→Th T1139M Tm NlaIII 1 (1.1%) yes 0 K11 exon 29 3644G→A R1215Q Tm NciI 1 (1.1%) yes 0 J10g intron 32 3992-9G→Ai aberrant splicing NBF-2 NciI 4 (4.5%) yes 0 C3e intron 32 3992-3C→G aberrant splicing NBF-2 AvaI 1 (1.1%) yes 0 L12 exon 34 4135G→C G1379R NBF-2 EagI 1 (1.1%) yes 0 M13 exon 34 4144G→A G1382S NBF-2 BglI 1 (1.1%) yes 0 B2d exon 34 4162delTTCi,j delF 1388 NBF-2 BseRI 1 (1.1%) yes 0 J10g exon 34 4181G→Ah R1394H NBF-2 DraIII 1 (1.1%) yes 0 N14 exon 35 4310G→Ai aberrant splicing NBF-2 MspI 1 (1.1%) yes 0 O15 exon 37 4525insCGGCTT insertion of AlaSer ft d 1508 NBF-2 PvuIIk 1 (1.1%) yes 0 after codon 1508 aNucleotide and codon positions are according to the full-length human SUR1 cDNA sequence incorporating the alternative splicedform of exon 17 (GenBank accession nos L78208 and L78216).
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ABCC8 p.Arg74Gln 9618169:63:249
status: NEW200 A model for SUR1 (29) predicts that the remaining seven missense mutations (Arg74Gln, His125Gln, Asn188Ser, Asn406Asp, Phe591Leu, Thr1139Met, Arg1215Gln) are located either within transmembrane segments or are present on the extracellular or cytoplasmic loops connecting adjacent trans- membranehelices.Theidentificationofthesemissensemutations in HI patients provides a basis for further studies to elucidate the functions of these transmembrane domains in SUR1 and KATP channel activity.
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ABCC8 p.Arg74Gln 9618169:200:76
status: NEW203 The functional significance of the Arg74Gln and Asn406Asp mutations upon SUR1 regulation of KATP channel activity are currently unknown.
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ABCC8 p.Arg74Gln 9618169:203:35
status: NEW[hide] Mutation spectra of ABCC8 gene in Spanish patients... Hum Mutat. 2006 Feb;27(2):214. Fernandez-Marmiesse A, Salas A, Vega A, Fernandez-Lorenzo JR, Barreiro J, Carracedo A
Mutation spectra of ABCC8 gene in Spanish patients with Hyperinsulinism of Infancy (HI).
Hum Mutat. 2006 Feb;27(2):214., [PMID:16429405]
Abstract [show]
Hyperinsulinism of Infancy (HI) is a clinical disorder characterized by deregulation of insulin secretion that leads to profound hypoglycemia. Mutations in genes encoding the ATP-regulated potassium channels of the pancreatic beta-cell, namely ABCC8 (SUR1) and KCNJ11 (Kir6.2), are the major genetic known cause of the disease. To elucidate the genetic etiology of HI in the uncharacterized Spanish population, we conducted extensive sequencing analysis of the ABCC8 (83.5Kb) and KCNJ11 (1.7Kb) genes in 34 Spanish HI patients. Mutations in ABCC8 were detected for both alleles in 13 patients, while ten patients carried only one mutation in one of the ABCC8 alleles. We have detected 22 novel and seven previously described mutations in ABCC8, approximately 60% of them lead to a premature termination signal, which would result in truncated SUR1 proteins. No mutations were found in the KCNJ11 gene. In addition, we report for the first time a 3914bp macrodeletion associated with the HI disorder. The potential pathogenicity of several additional variants is discussed. The spatial pattern of three pathological mutations suggests possible geographical founder effects. This work reveals for first time the involvement of KATP channels in the pathogenesis of an important proportion (approximately 68%) of Spanish HI patients. The spectrum of mutations in Spanish HI patients provides an important tool for diagnosis and prognosis of HI patients in the Spanish population, as well as for genetic counseling of HI families.
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107 Although R74W was found for first time in our population, Nestorowicz et al. (1998) described a different amino acid change at the same codon (R74Q).
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ABCC8 p.Arg74Gln 16429405:107:143
status: NEW