To report in African Americans with type 1 diabetes the association of single-nucleotide polymorphisms in 193 candidate genes with diabetic retinopathy (DR) and/or its progression.
A custom panel of 1536 single-nucleotide polymorphisms located on 193 candidate genes for DR was genotyped in 437 African Americans with type 1 diabetes who participated in the New Jersey 725 study. Clinical evaluations at baseline and follow-up examinations included structured clinical interview, ocular examination, 7-field stereoscopic fundus photographs, and blood pressure measurements. Severity of DR was determined via masked grading of fundus photographs. Biological evaluations included blood and urine assays.
Single-nucleotide polymorphisms in 13 candidate genes for DR involved in glucose metabolism, angiogenesis, inflammation, neurotransmission, hypertension, and retinal development were significantly associated with the prevalence of severe DR. Three of these genes were also significantly associated with progression of DR. Adjusting for sex, duration of diabetes, glycosylated hemoglobin, systemic hypertension, and total cholesterol did not alter the results.
Our data support the role of genetic factors to account for severity and/or progression of DR in African Americans with type 1 diabetes and to identify several prime genes that likely contribute to the risk of DR.