FREQUÊNCIA DA VARIANTE GENÉTICA VAL66MET EM PACIENTES PORTADORES DE GLAUCOMA EM SALVADOR

Abstract

Glaucoma is a very common condition and its diagnosis is often difficult and late. BDNF is a neuropeptide whose trophic function helps protect retinal ganglion cells. Low levels of BDNF have been associated with glaucoma in several studies. In the search for elucidation of the pathophysiology of glaucoma, in this work, we described the frequency of a genetic variant, val66met (rs6265), in a population of glaucoma patients and associated the presence of this variant with the different phenotypes of the disease. To this end, a total of 200 patients were recruited at the Oftalmodiagnose clinic. Patients are followed up in this clinic by the Clinical Protocol and Therapeutic Guidelines for Glaucoma, in which patients receive regular monitoring of the disease and eye drops for its treatment. The diagnosis of primary open-angle glaucoma is made with intraocular pressure above 21 mmHg, papillary cupping above 0.5, and/or visual field defect. 8 ml of venous blood was obtained from each patient, plasma was separated for BDNF measurement via Luminex and the buffy coat was used to extract genomic DNA. Genotyping was performed through real-time PCR using Taqman technology in QuantStudio 12K equipment. The population had a mean age of 63.19 (11.18) years. 46.8% of patients had advanced / severe disease and 53.2% were classified as having an early / moderate disease. We found a low genotypic frequency (8.6%) of the variant allele (T) in relation to the most common one (C). We found no significant differences between glaucoma severity and allele frequencies. We tested BDNF plasma levels among cases and controls. Mean values were 17.01 (SD 3.92) pg/ml for cases and 365.46 (SD 111.59) pg/ml for controls. This difference was suggestive of statistical significance (p<0.01), despite the small number of samples already examined. Our study suggests that BDNF may be a biomarker for the diagnosis of glaucoma.