Evaluation of VEGF gene polymorphisms and proliferative diabetic retinopathy in Mexican population.
OBJECTIVE
To assess if the included vascular endothelial growth factor (VEGF) polymorphisms rs3025035, rs3025021 and rs2010963 are associated to proliferative retinopathy in a Mexican population with type 2 diabetes mellitus (T2DM).


METHODS
A case-control study was conducted in adult individuals with T2DM associated to proliferative retinopathy or non-proliferative retinopathy from Oct. 2014 to Jun. 2015 from the Retina Department of the Asociation to Prevent Blindness in Mexico. The selected patients were adults with a diagnosis of T2DM ≥5y. All subjects had a comprehensive ocular examination and the classification of the retinopathy severity was made considering the Early Treatment Diabetic Retinopathy Study (ETDRS) standardization protocols. Genomic DNA was extracted from whole fresh blood. All samples were genotyped by qPCR for selected VEGF polymorphisms. Hardy-Weinberg equilibrium was calculated by comparing Chi-square values between the expected and the observed values for genotype counts.


RESULTS
In total 142 individuals were enrolled, 71 individuals with T2DM and associated proliferative retinopathy and 71 individuals with non-proliferative retinopathy. One-sided Fisher's exact test was performed for rs3025021 [OR (95% CI)=0.44(0.08-2.2);P=0.25] and rs2010963 [OR (95% CI)=0.63(0.25-1.6);P=0.23]. The minor allelic frequencies obtained were 26% for rs3025021, 10% for rs3025035 and 61% for rs2010963. The pairwise linkage disequilibrium between the three SNP was assessed, and was as follows: rs3025021vsrs3025035: D'=1.0,r2=0.1043,P≤0.0001; rs3025021vsrs2010963: D'=0.442,r2=0.0446,P=0.149; rs3025035vsrs2010963: D'=0.505,r2=0.0214,P=0.142.


CONCLUSIONS
This is the first analysis involving VEGF polymorphisms and proliferative diabetic retinopathy in a Mexican population. A major finding of the present study is that none of the polymorphisms studied was significantly associated with proliferative retinopathy. Based on these results, we can infer that different populations have different associations for the same polymorphisms.
Biomedical Research Department, Autonomous University of Queretaro, Queretaro 76170, Mexico; Research Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Roberto
R
Gonzalez-Salinas
Biomedical Research Department, Autonomous University of Queretaro, Queretaro 76170, Mexico.
Maria C
MC
Garcia-Gutierrez
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Gerardo
G
Garcia-Aguirre
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Virgilio
V
Morales-Canton
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Raul
R
Velez-Montoya
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Vidal R
VR
Soberon-Ventura
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Victoria
V
Gonzalez
Retina Department, Asociation to Prevent Blindness in Mexico, Mexico City 04030, Mexico.
Rodrigo
R
Lechuga
Biomedical Research Department, Autonomous University of Queretaro, Queretaro 76170, Mexico.
Pablo
P
Garcia-Solis
Biomedical Research Department, Autonomous University of Queretaro, Queretaro 76170, Mexico.
David G
DG
Garcia-Gutierrez
Retina Department, General Hospital of Queretaro (ISSSTE), Queretaro 76000, Mexico.
Marco Vinicio
MV
Garcia-Solis
Universidad La Salle School of Medicine, Mexico City 06140, Mexico.
Manuel
M
Saenz de Viteri
Biomedical Research Department, Autonomous University of Queretaro, Queretaro 76170, Mexico.
Juan C
JC
Solis-S
VEGF polymorphism; non-proliferative diabetic retinopathy; proliferative diabetic retinopathy; rs2010963; rs3025021; rs3025035