RESUMEN
PURPOSE: To investigate whether the G6721T polymorphism (rs.7003908) of the non-homologous end-joining DNA repair XRCC7 gene contributes to the development of exudative age-related macular degeneration (ARMD). METHODS: The present case-control study consisted of 111 patients with exudative ARMD and 112 sex frequency-matched healthy controls that were randomly selected from unrelated volunteers in the same clinic. Genotypes were determined by the Restriction Fragment Length Polymorphism (PCR-RFLP) based method. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ARMD risk associated with polymorphism of XRCC7. In all analysis the GG genotype was considered to be the reference genotype. RESULTS: There was no significant association between genotypes of XRCC7 and susceptibility to ARMD. Considering the significant difference in age distribution between cases and controls, age was used as a covariate in further analysis. After ORs were adjusted for age, the same result was observed. In the next step we stratified our subjects into outdoor and indoor groups according to their job titles. The outdoor and indoor patients were occupationally exposed to sunlight and not exposed to sunlight, respectively. Our present study showed that among indoor subjects there was no association between XRCC7 polymorphism and susceptibility to ARMD. However, among outdoor subjects, the GT + TT genotypes compared to the GG genotype increased the risk of ARMD (OR, 3.13; 95% CI, 1.04-9.39; p = 0.042). CONCLUSIONS: Our study revealed that the T allele of the G6721T polymorphism of XRCC7 increased the risk of ARMD among outdoor subjects.
Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , ADN/genética , Proteína Quinasa Activada por ADN/genética , Exposición a Riesgos Ambientales , Exudados y Transudados , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Genotipo , Degeneración Macular/genética , Proteínas Nucleares/genética , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Phenylketonuria [PKU] is one of the most common metabolic inborn diseases caused by mutations in the phenylalanine hydroxylase [PAH] gene. This gene is linked to a variable number of tandem repeats [VNTR] region which is a polymorphic marker that facilitates the implementation of prenatal diagnosis and carrier screening. In this study, VNTR with 13 repeats that has not been reported previously was observed in 2 PKU families from Fars province, south of Iran. This allele showed 4% frequency in normal individuals