ABCA1 p.Arg1851Gly
| Predicted by SNAP2: | A: D (66%), C: D (59%), D: D (80%), E: D (63%), F: D (71%), G: D (71%), H: N (53%), I: D (71%), K: N (97%), L: D (71%), M: D (63%), N: D (63%), P: D (80%), Q: D (63%), S: D (66%), T: D (59%), V: D (71%), W: D (63%), Y: D (66%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: N, F: D, G: D, H: D, I: D, K: N, L: D, M: D, N: D, P: D, Q: N, S: D, T: D, V: D, W: D, Y: D, |
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[hide] Novel polypyrimidine variation (IVS46: del T -39..... Circ Res. 2003 Nov 14;93(10):1006-12. Epub 2003 Oct 23. Hong SH, Rhyne J, Miller M
Novel polypyrimidine variation (IVS46: del T -39...-46) in ABCA1 causes exon skipping and contributes to HDL cholesterol deficiency in a family with premature coronary disease.
Circ Res. 2003 Nov 14;93(10):1006-12. Epub 2003 Oct 23., [PMID:14576201]
Abstract [show]
Recent studies have implicated mutations in the ATP-binding cassette transporter A1, ABCA1, as a cause of Tangier disease (TD) and familial hypoalphalipoproteinemia (FHA). We investigated a proband with very low levels of high-density lipoprotein cholesterol (HDL-C, 6 mg/dL) and a history of premature coronary heart disease (CHD). Sequencing of the ABCA1 gene revealed 2 distinct variants. The first mutation was a G5947A substitution (R1851Q). The second mutation was a single-nucleotide deletion of thymidine in a polypyrimidine tract located 33 to 46 bps upstream to the start of exon 47. This mutation does not involve the 3' acceptor splice site and is outside the lariat branchpoint sequence (IVS46: del T -39...-46). Amplification of cDNA obtained in cultured fibroblasts of the proband and affected family member revealed an abnormally spliced cDNA sequence with skipping of exon 47. These variants were not identified in over 400 chromosomes of healthy whites. Compound heterozygotes (n=4) exhibited the lowest HDL-C (11+/-5 mg/dL) and ApoA-I (35+/-15 mg/dL) compared with wild-type (n=25) (HDL-C 51+/-14 mg/dL; ApoA-I 133+/-21 mg/dL) (P<0.0005) or subjects affected with either R1851Q (n=6) (HDL-C 36+/-8; ApoA-I 117+/-19) or IVS46: del T -39...-46 (n=5) (HDL-C 31+9; ApoA-I 115+28 (P<0.01). These data suggest that polypyrimidine tract variation may represent a novel mechanism for altered splicing and exon skipping that is independent of traditional intronic variants as previously identified in acceptor/donor splice regions or the lariat branchpoint domain.
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100 between premature CHD and either increased carotid intimal-medial thickness or reduced ABCA1-mediated cholesterol efflux.25-27 The premature CHD identified in the proband extends previous observational data in normolipidemic indi- viduals1-3 and may not only reflect alterations in RCT but other recently identified antiatherogenic effects potentially subserved by HDL including reduced ischemic-reperfusion injury28 and improved vascular function.29 To date, only a small proportion of ABCA1 variants have been characterized in pivotal regions (eg, extracellular loop, transmembrane domain, nucleotide binding folds, C-terminus) that when altered, result in marked reduction in ABCA1 activity and/or function.6,7 The G5947A/ R1851Q mutation occurs within the extracellular loop proximal to the final transmembrane spanner and bears regional similarity to the C5946T/R1851X variant recently reported in a compound heterozygote with TD.30 Variants located within the extracellular loop (between amino acids 1370 to 1650) have been shown to adversely affect the interaction of ABCA1 and ApoA-I resulting in reduced cholesterol efflux.31 Whether distal variants (eg, N1800H, R1851G) exhibit similar interactions with ApoA-I has not been studied, but the marked reductions in HDL-C that have been observed in affected subjects suggest that binding may be similarly disrupted.
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ABCA1 p.Arg1851Gly 14576201:100:1172
status: NEW95 Ho Hong et al Exon Skipping in ABCA1 and HDL-C Deficiency between premature CHD and either increased carotid intimal-medial thickness or reduced ABCA1-mediated cholesterol efflux.25-27 The premature CHD identified in the proband extends previous observational data in normolipidemic indi- viduals1-3 and may not only reflect alterations in RCT but other recently identified antiatherogenic effects potentially subserved by HDL including reduced ischemic-reperfusion injury28 and improved vascular function.29 To date, only a small proportion of ABCA1 variants have been characterized in pivotal regions (eg, extracellular loop, transmembrane domain, nucleotide binding folds, C-terminus) that when altered, result in marked reduction in ABCA1 activity and/or function.6,7 The G5947A/ R1851Q mutation occurs within the extracellular loop proximal to the final transmembrane spanner and bears regional similarity to the C5946T/R1851X variant recently reported in a compound heterozygote with TD.30 Variants located within the extracellular loop (between amino acids 1370 to 1650) have been shown to adversely affect the interaction of ABCA1 and ApoA-I resulting in reduced cholesterol efflux.31 Whether distal variants (eg, N1800H, R1851G) exhibit similar interactions with ApoA-I has not been studied, but the marked reductions in HDL-C that have been observed in affected subjects suggest that binding may be similarly disrupted.
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ABCA1 p.Arg1851Gly 14576201:95:1232
status: NEW