Non-insulin-dependent diabetes mellitus and the 5' hypervariable region of the insulin gene in two South African Indian families.

The hypervariable region 5' to the human insulin gene has been characterised in two South African Indian families, each having two generations of individuals affected with non-insulin-dependent diabetes mellitus (NIDDM). Southern blot analysis, with the restriction endonuclease Pvu II and plasmid phins 310 as a probe, was used. In family 1, class 1 alleles (0.87, 0.79, 0.72 and 0.68 kilobase (kb)) were found at this locus but no linkage with NIDDM was shown. In family 2 a class 3 (2.51 kb) and two class 1 alleles (0.89, 0.76) were found. The 0.89 kb allele appears to be segregating with NIDDM in this family.