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Journal of Ophthalmology
Volume 2010 (2010), Article ID 861291, 9 pages
http://dx.doi.org/10.1155/2010/861291
Research Article

Identification of Diabetic Retinopathy Genes through a Genome-Wide Association Study among Mexican-Americans from Starr County, Texas

1Human Genetics Center, School of Public Health, The University of Texas Health Science Center at Houston, P.O. Box 20186, Houston, TX 77225, USA
2Valley Retina Institute, McAllen, TX 78503, USA
3Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
4Division of Endocrinology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
5Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA

Received 18 December 2009; Revised 22 May 2010; Accepted 14 July 2010

Academic Editor: Kavita Hegde

Copyright © 2010 Yi-Ping Fu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

To identify genetic loci for severe diabetic retinopathy, 286 Mexican-Americans with type 2 diabetes from Starr County, Texas, completed physical examinations including fundus photography for diabetic retinopathy grading. Individuals with moderate-to-severe non-proliferative and proliferative diabetic retinopathy were defined as cases. Direct genotyping was performed using the Affymetrix GeneChip Human Mapping 100 K Set, and SNPs passing quality control criteria were used to impute markers available in HapMap Phase III Mexican population (MXL) in Los Angeles, California. Two directly genotyped markers were associated with severe diabetic retinopathy at a P-value less than .0001: SNP rs2300782 ( 𝑃 = 6 . 0 4 × 1 0 5 ) mapped to an intron region of CAMK4 (calcium/calmodulin-dependent protein kinase IV) on chromosome 5, and SNP rs10519765 ( 𝑃 = 6 . 2 1 × 1 0 5 ) on chromosomal 15q13 in the FMN1 (formin 1) gene. Using well-imputed markers based on the HapMap III Mexican population, we identified an additional 32 SNPs located in 11 chromosomal regions with nominal association with severe diabetic retinopathy at P-value less than .0001. None of these markers were located in traditional candidate genes for diabetic retinopathy or diabetes itself. However, these signals implicate genes involved in inflammation, oxidative stress and cell adhesion for the development and progression of diabetic retinopathy.