Is diabetic nephropathy inherited separately from diabetes?
A number of observations suggest that genes that predispose to diabetic nephropathy also predispose to type 2 diabetes. McCance et al. [19] have found that subjects had a greater risk of diabetes if their type 2 diabetic parents had established nephropathy, compared to those whose parents had diabetes without nephropathy. A parental history of type 2 diabetes is associated with increased risk of proteinuria in type 1 diabetic patients [43]. On the other hand, non-diabetic offspring of diabetic patients with nephropathy have a higher albumin excretion rate compared to non-diabetic offspring of diabetic patients without nephropathy [21]. Furthermore, Freedman et al. [44] have reported that African Americans with end-stage renal disease (ESRD) secondary to type 2 diabetes have a relative with ESRD more commonly than do type 2 diabetic patients without nephropathy. Non-diabetic renal disease also exhibits familial aggregation [45]. One way to reconcile these observations is to hypothesize
