No evidence for a major effect of two common polymorphisms of the catalase gene in type 1 diabetes susceptibility.

Type 1 diabetes (T1D) is a multifactorial disease, the genetic analysis of which has yielded few true positive linkage and association results. Replication of association in independent, large-sample studies is essential to further identify the genes involved in T1D. Two single nucleotide polymorphisms (SNPs) in the catalase gene have been reported to be associated with T1D. Major effects of two SNPs, C1167T (rs769217) and C(-262)T (rs1001179), of the catalase gene on T1D susceptibility have been reported previously in Russians from Moscow. We genotyped C1167T and C(-262)T in large family (1642 families) and British case-control (3530 cases and 3930 controls) collections and tested for association with T1D. We found no evidence of an association between T1D and C1167T or C(-262)T in either the family or case-control collections, or for the D11S2008 microsatellite polymorphism in families. However, we did find limited statistical evidence of an association at C1167T in USA families (P = 0.033; RR for 1167C = 1.23, 95% CI = 1.02-1.49) and C(-262)T in UK families (P = 0.046; RR for (-262)C = 0.86, 95% CI = 0.75-0.99). We found no evidence for a major effect of C1167T or C(-262)T on T1D susceptibility in two large sample collections. Limited statistical evidence of an association at C1167T in USA families and C(-262)T in UK families was found, but these results are likely to be false positives. The previously reported association of these SNPs may also have been a false positive, or a population specific association in Russians from Moscow.