THE SIGNIFICANCE OF A POSITIVE FAMILY HISTORY IN SOUTH-AFRICAN INDIANS WITH NON-INSULIN-DEPENDENT DIABETES (NIDDM)

A group of South African Indians with NIDDM participated in a study to evaluate the frequency of positive family histories of the disease an d to determine the relative contribution of maternal or paternal genet ic determinants, Information was elicited by means of an interview and recorded. Of the 1098 diabetic subjects studied 70% gave a positive f amily history of a first degree relative suffering from NIDDM, Three-g eneration transmission was recorded in 5.3% of the subjects. A signifi cantly greater proportion of probands (40%) had a mother with NIDDM th an those with a Father (26%). A positive family history in an offsprin g was more common in female probands (10.6%) than males (5.5%). Twice as many probands with 3 generation transmission had a maternal grandmo ther suffering from NIDDM (2.5%) compared with those who had a paterna l grandmother afflicted (1.2%,) (P <0.05), whereas the frequencies in the maternal (0.9%) and paternal (0.8%) grandfathers were similar. Thi s study has highlighted, not only the high prevalence of a positive fa mily history in South African Indians with NIDDM, but also a stronger maternal contribution to the putative gene responsible for the disease .