Promoter polymorphism at the tumour necrosis factor/lymphotoxin-alpha locus is associated with type of diabetes but not with susceptibility to sight-threatening diabetic retinopathy

<strong>AIM:</strong> To investigate, in a large cohort of 2494 individuals with diabetes mellitus, whether functional single nucleotide polymorphisms in the promoter region of <i>tumour necrosis factor (TNF)</i> and <i>lymphotoxin-alpha (LTA)</i> genes are associated with type of diabetes or presence of diabetic retinopathy.<p></p> <p><strong>METHODS:</strong> A total of 334 type 1 diabetes and 999 type 2 diabetes participants with sight-threatening diabetic retinopathy, and 260 type 1 diabetes and 901 type 2 diabetes participants with no diabetic retinopathy or minimal non-proliferative diabetic retinopathy, were genotyped for two single nucleotide polymorphisms (rs1800629 and rs361525).</p> <p><strong>RESULTS:</strong> The A allele of rs1800629 was associated with type 1 diabetes (p < 0.001; odds ratio = 0.62). After adjustment for age, sex, diabetes duration, HbA1c, hypertension and nephropathy, no significant association was found between rs1800629 or rs361525 and sight-threatening diabetic retinopathy.</p> <p><strong>CONCLUSION:</strong> An association between the A allele of rs1800629 and type of diabetes was found. No association was found between two promoter variants of <i>TNF</i> and <i>LTA</i>, and diabetic retinopathy in a large cohort of Caucasian patients with type 1 diabetes and type 2 diabetes.</p>