HLA-A2 and type 2 (insulin independent) diabetes mellitus in Pima Indians: an association of allele frequency with age.

In Pima Indians with Type 2 (insulin independent) diabetes mellitus, HLA-A2 allele frequencies were inversely associated with age, (0.72, 0.59, and 0.52 in those less than 35, 35 to 54, and 55 years old and over, respectively). This suggests that there may be a gene closely linked with the HLA-A locus which plays a role in the expression of diabetes in the Pimas by contributing to an earlier age of onset. HLA-A2 was found in 65% non-diabetic and 81% of 191 diabetic subjects (relative risk = 2.2).