catechol-o-methyltransferase (comt) gene (val158met) and brain-derived neurotropic factor (bdnf) (val66met) genes polymorphism in schizophrenia: a case-control study

Objective: several studies have shown that some polymorphisms of genes encoding catechol-o-methyltransferase (comt), the key enzyme in degrading dopamine, and norepinephrine and the human brain-derived neurotropic factor (bdnf), a nerve growth factor, are strong candidates for risk of schizophrenia (scz). in the present study, we aimed at examining the effects of comt val158met (g>a) and bdnf val66met (g>a) polymorphisms on scz risk in a sample of iranian population. method: this case- control study included 92 scz patients and 92 healthy controls (hcs). genotyping of both variants (comt val158met (g>a) and bdnf val66met (g>a)) were conducted using amplification refractory mutation system-polymerase chain reaction (arms-pcr). results: the findings revealed that the comt val158met (g>a) polymorphism was not associated with the risk/protective of scz in all models (or=0.630, 95%ci=0.299-1.326, p=0.224, ga vs. gg, or=1.416, 95%ci=0.719-2.793, p=0.314, aa vs. gg, or=1.00, 95%ci=0.56-1.79, p=1.00 ga+aa vs. gg, or=1.667, 95%ci=0.885-3.125, p=0.11, aa vs. gg+ga, or=1.247, 95%ci=0.825-1.885, p=0.343, a vs. g,). however, bdnf val66met (g>a) variant increased the risk of scz (or = 2.008 95%ci = 1.008-4.00, p = 0.047, ga vs. gg, or = 3.876 95%ci = 1.001-14.925, p = 0.049. aa vs. gg, or = 2.272. 95%ci = 1.204-4.347, p = 0.011, ga+aa vs. gg, or = 2.22 95%ci = 1.29-3.82. p = 0.005, a vs. g). conclusion: the results did not support an association between comt val158met (g>a) variant and risk/protective of scz. moreover, it was found that bdnf val66met (g>a) polymorphism may increase the risk of scz development. further studies and different ethnicities are recommended to confirm the findings.