title: Effect of polymorphism in insulin locus and HLA on type 1 diabetes in four ethnic groups in Israel.
abstract: This study examined a possible association of the insulin (INS) gene with type 1 diabetes (T1D) in patients and controls from four ethnic groups in Israel. We analyzed the distribution of -23HphI single nucleotide polymorphism (SNP) T/A alleles that correspond to INS variable number of tandem repeat short class I alleles (26-63 repeats) and class III alleles (141-209 repeats), respectively. The -23HphI T/T genotype was found to be positively associated with T1D in three Jewish groups (Yemenites: 93.9% patients vs 68.8% controls, P = 0.0002; Ashkenazi: 80.6% vs 50.8%, P < 10(-4); Ethiopians: 75% vs 40.5%, P = 0.002). The Yemenite healthy controls have the highest frequency of T allele from all Jewish groups studied (83.5% vs 68.8% in Ashkenazi and 64.3% in Ethiopians). The high frequency of a susceptibility allele in the Yemenites is in line with the high incidence of T1D in this population. No association was observed between T1D and the INS gene in Israeli Arabs studied (70.6% vs 66.7%). Variable incidence of T1D among different ethnicities in Israel is largely attributed to heterogeneous genetics. Human leukocyte antigen (HLA) results of our previous studies describing the susceptibility and protective haplotypes were used for combined analysis to determine possible interaction between the HLA and INS loci. Only in the Ashkenazi group such interaction was presented with statistical significance.
authors.affiliation: The Lautenberg Center for General and Tumor Immunology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: G
authors.initials: G
authors.lastname: Benedek
authors.forename: C
authors.initials: C
authors.lastname: Brautbar
authors.forename: P
authors.initials: P
authors.lastname: Vardi
authors.forename: N
authors.initials: N
authors.lastname: Sharon
authors.forename: N
authors.initials: N
authors.lastname: Weintrob
authors.forename: A
authors.initials: A
authors.lastname: Zung
authors.forename: S
authors.initials: S
authors.lastname: Israel
mesh_terms: D000293:Adolescent; D000483:Alleles; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology* / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006239:Haplotypes; D006801:Humans; D007328:Insulin / Q000235:genetics*; D007557:Israel; D018598:Minisatellite Repeats; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007328:Insulin