AN INVESTIGATION OF THE ASSOCIATION BETWEEN HLA-DQ HETERODIMERS AND TYPE-1 (INSULIN-DEPENDENT) DIABETES-MELLITUS IN 5 RACIAL GROUPS

The association between HLA-DQ crArg52-HLA-DQ beta non-Asp57 heterodim ers and type 1 (insulin-dependent) diabetes was compared in Japanese, Chinese, Caucasian, North Indian Asian, and Afro-Caribbean patients to determine their importance in disease susceptibility. The potential t o encode four Arg52-non-Asp57 DQ heterodimers, two in cis and two in t rans, was significantly associated with increased risk of type 1 diabe tes in all races except the Japanese, The possibility of encoding two Arg52-non-Asp57 heterodimers was also significantly associated with in creased risk of the disease in all races except the Japanese. The poss ibility of encoding one heterodimer was not significantly associated w ith type 1 diabetes in any of the races studied. Heterogeneity testing revealed significant differences in RR values for four, two, and one heterodimers in all races except the Japanese and significant differen ces in RR for four and two heterodimers when compared across the races . This, together with the lack of an association between Arg52-non-Asp 57 heterodimers and type 1 diabetes in the Japanese, suggests that, as suming the same genetic basis for disease in all races, the heterodime r is unlikely to be of primary importance in susceptibility to the dis ease.