FAMILIAL AGGREGATION OF TYPE-2 (NON-INSULIN-DEPENDENT) DIABETES-MELLITUS IN SOUTH-INDIA ABSENCE OF EXCESS MATERNAL TRANSMISSION

The family histories of 976 South Indian Type 2 diabetic patients were recorded in a questionnaire-based survey to establish whether the exc ess maternal transmission of Type 2 diabetes reported in low prevalenc e Europid populations was also evident in this medium prevalence popul ation. In 450 families (46.1 %), no parental history of diabetes was r eported. In 423 families with one parent diabetic, 222 fathers (52.5 % ) and 201 (47.5 %) mothers were diabetic. In the remaining 103 (10.6 % ) families, both parents were diabetic. In contrast to previous studie s, we found no evidence for substantial maternal excess in the transmi ssion of diabetes (325 diabetic fathers vs 304 mothers; p = 0.4; p = 0 .07 when compared using life table methods). The age of diagnosis of d iabetes in probands was lower than that of their diabetic parents (p < 0.001): furthermore increasing parental history of diabetes was assoc iated with an earlier diagnosis of diabetes in probands (p < 0.001). T hese results emphasize the extensive familial aggregation of Type 2 di abetes in this population but fail to replicate the evidence for exces s maternal transmission evident in lower prevalence Europid population s, suggesting ethnic differences in the extent of this phenomenon.