Ophthalmic Genetics, 28:77–81, 2007 Copyright c  Informa Healthcare ISSN: 1381-6810 (print) / 1744-5094 (online) DOI: 10.1080/13816810701209669 RESEARCH ARTICLE Intron 4 VNTR of Endothelial Nitric Oxide Synthase (eNOS) Gene and Diabetic Retinopathy in Type 2 Patients in Southern India Satagopan Uthra SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India Rajiv Raman Shri Baghawan Mahavir Vitreo-Retinal Services, Chennai, India Bickol N. Mukesh Sankara Nethralaya Diabetic Retinopathy Project, Medical & Vision Research Foundations, Chennai, India Padmaja Kumari R Shri Baghawan Mahavir Vitreo-Retinal Services, Chennai, India Pradeep G. Paul Sankara Nethralaya Diabetic Retinopathy Project, Medical & Vision Research Foundations, Chennai, India Praveena Lakshmipathy SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India Perumal Gnanamoorthy Sankara Nethralaya Diabetic Retinopathy Project, Medical & Vision Research Foundations, Chennai, India Tarun Sharma Shri Baghawan Mahavir Vitreo-Retinal Services, Chennai, India Catherine A. McCarty Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA Govindasamy Kumaramanickavel SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India A 27-bp variable number tandem repeat (VNTR) in intron 4 of endothelial nitric oxide synthase (eNOS) gene has been associated with the risk for developing diabetic retinopathy (DR) in various ethnic populations. Hundred and eighty seven patients with retinopathy (cases; DR+) and 188 patients without retinopathy (controls: DR−) from southern India who had type 2 diabetes mellitus (T2DM) for more than 10 years, were included in the study. We could neither find significant allelic association with clinical severity of DR nor with macular edema. Our results suggest lack of association of intron 4 VNTR of eNOS gene with DR in southern India. Keywords Diabetic retinopathy; hypoxia, eNOS; intronic VNTR; type 2 diabetes Received; accepted 10 January 2007. Address correspondence to Dr. Govindasamy Kumaramanickavel, SN ONGC Department of Genetics and Molecular Biology, Vision Re- search Foundation, Sankara Nethralaya, 18, College Road, Chennai 600 006, India; Tel: 91-44-42271807; Fax: 91-44-28254180; E-mail: gkumarmvel@rediffmail.com 77