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 excess maternal transmission of Type 2 diabetes reported in low prevalence Europid populations was also evident in this medium prevalence population. In 450 families (46.1%), no parental history of diabetes was reported. 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 studies, we found no evidence for substantial maternal excess in the transmission 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 diabetes in probands was lower than that of their diabetic parents (p < 0.001): furthermore increasing parental history of diabetes was associated with an earlier diagnosis of diabetes in probands (p < 0.001). These results emphasize the extensive familial aggregation of Type 2 diabetes in this population but fail to replicate the evidence for excess maternal transmission evident in lower prevalence Europid populations, suggesting ethnic differences in the extent of this phenomenon.
Viswanathan
M
M
Diabetes Research Centre, Madras, India.
McCarthy
M I
MI
Snehalatha
C
C
Hitman
G A
GA
Ramachandran
A
A
D000328:Adult; D017668:Age of Onset; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics* / Q000401:mortality; D005220:Fathers; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D007194:India; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D009035:Mothers; D009679:Nuclear Family; D010375:Pedigree