Diabetic nephropathy (defined as urinary albumin excretion greater than 300 mg/24 hr) was found in 7 out of 21 siblings to patients with nephropathy and 3 out of 30 siblings to normoalbuminuric patients (P less than 0.04).
In one set, the probands (n = 11) had no evidence of diabetic nephropathy, with normal creatinine clearance and a urinary albumin excretion rate below 45 mg per day.
It has been recently reported that in type 1 diabetes the insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme gene is associated with the presence of diabetic nephropathy.
Insertion/deletion polymorphism in the angiotensin-I-converting enzyme gene is associated with coronary heart disease in IDDM patients with diabetic nephropathy.
Lack of relationship between an insertion/deletion polymorphism in the angiotensin I-converting enzyme gene and diabetic nephropathy and proliferative retinopathy in IDDM patients.
Genotypic abnormalities of the renin-angiotensin system have been suggested as a risk factor for the development of diabetic nephropathy and proliferative retinopathy.
Studies have shown an association of diabetic nephropathy and ischaemic heart disease with angiotensin converting enzyme gene polymorphism in subjects with diabetes.