کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3368347 1592314 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The MHC type 1 diabetes susceptibility gene is centromeric to HLA-DQB1
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی
پیش نمایش صفحه اول مقاله
The MHC type 1 diabetes susceptibility gene is centromeric to HLA-DQB1
چکیده انگلیسی

HLA-DQB1 is widely considered to be the major histocompatibility complex (MHC) susceptibility gene for type 1 diabetes (T1D). However, since inheritance of the gene in T1D is recessive, the presence of the protective HLA-DQB1*0602 allele with normal nucleotide sequence in some patients raises the question of whether HLA-DQB1 is not the susceptibility locus itself but merely a good marker. HLA-DQB1*0602 is part of a conserved extended haplotype (CEH) [HLA-B7, SC31, DR2] (B7, DR2) with fixed DNA over more than 1 Mb of genomic DNA that normally carries a protective allele at the true susceptibility locus. We postulated that, in patients with HLA-DQB1*0602, the protective allele at the susceptibility locus has been replaced by a susceptibility allele through an ancient crossover at meiosis centromeric to HLA-DQB1. We analyzed single nucleotide polymorphisms (SNPs) distinguishing the HLA-DQA2 (the first expressed gene centromeric to HLA-DQB1) allele on the normal HLA-B7, DR2 CEH from those on susceptibility CEHs in T1D patients and controls with HLA-DQB1*0602. All but 1 of 20 healthy control HLA-DQB1*0602 haplotypes had identical (consensus) first intron HLA-DQA2 5-SNP haplotypes. Fifteen of 19 patients with HLA-DQB1*0602 were homozygous for 1 or more HLA-DQA2 SNPs differing from consensus HLA-DQA2 SNPs, providing evidence of crossover involving the HLA-DQA2 locus. The remaining 4 patients were heterozygous at all positions and therefore uninformative. The loss of dominant protection usually associated with HLA-DQB1*0602 haplotypes is consistent with a locus centromeric to HLA-DQB1 being a major determinant of MHC-associated susceptibility, and perhaps the true T1D susceptibility locus.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Autoimmunity - Volume 30, Issue 4, June 2008, Pages 266–272
نویسندگان
, , , , , , ,