HLA genetics of insulin-dependent juvenile-onset diabetes mellitus in northern Finland.

HLA--A, B and C antigens were determined from 63 cases of juvenile-onset, insulin-dependent diabetes mellitus (IDDM) in northern Finland. There was a very strong association between IDDM and HLA--B8 and B15 antigens in this area where the incidence of IDDM is also high. Relative risks for B8 and B15 were 4.8 and 3.8, respectively. In a small group of subjects typed for HLA--D antigens Dw3 and Dw4 appeared to be stronger risk factors than associated B antigens, whereas Dw2 was almost totally absent in the patients. The effect of combinations of B8 and B15 antigens in unrelated patients and in diabetic families was analyzed. B8, B15 was found in 11 out of 63 unrelated diabetics; however, this did not differ significantly from the expected value. In diabetic families there was no increased rate of intra-HLA recombinations.