P1A1/P1A2 polymorphism of platelet glycoprotein IIIa receptor and microangiopathy in type 1 diabetes mellitus

Diabetes clusters renal and cardiovascular complications. Genes that influence factors affecting cardiovascular risk may be studied in relation to nephropathy. The gene encoding GPIIIa shows polymorphism (Pl(Al)/Pl(A2)); the Pl(A2) allele has been associated with cardiovascular events. In 368 type 1 diabetics we evaluated the relationship between GPIIIa gene polymorphism and diabetic nephropathy and retinopathy; 76 healthy controls were studied for comparison. A fragment of 247 bp (encompassing exon 2) was amplified by PCR. For the detection of the point mutation CDGE was employed. The allele frequency of pl(A2) was 11.6% in IDDM and 8.6% in controls. A1/A1 and A1/A2 genotypes occurred in 77% and 23% of IDDM, 83% and 17% of controls. The distribution of GPIIIa genotypes was: 177 (76%) A1/A1 and 57 (24%) A1/A2 in normoalbuminurics (n.234, 64%); 62 (79%) A1/A1 and 16(21%) A1/A2 in microalbuminurics (n. 78, 21%); 42 (75%) A1/A1 and 14 (25%) A1/A2 in macroalbuminuric patients (n. 56, 15%; chi(2)=0,16; p=0,68). As far as retinopathy is concerned the distribution of genotypes was: 96 (77%) A1/A1 and 28 (23%) A1/A2 in IDDM with no retinopathy (n. 124, 34%), 92 (77%) A1/A1 and 28 (23%) A1/A2 in patients with background retinopathy (n. 120, 32%), 96 (77%) A1/A1 and 28 (23%) A1/A2 in patients with proliferative retinopathy (n. 124, 34%; p=0,98). In a large cohort of Caucasian patients with type 1 diabetes, no association was observed between the Pl(A1)/Pl(A2) polymorphism of the GPIIIa and diabetic nephropathy and retinopathy.