ANÁLISE DO POLIMORFISMO DO GENE CYP1A1m1 EM PACIENTES COM GLAUCOMA PRIMÁRIO DE ÂNGULO ABERTO DE UMA CLÍNICA OFTALMOLÓGICA EM GOIÂNIA, GO.

Abstract

Glaucoma encompasses a group of eye diseases characterized by retinal ganglion cell damage, optical nerve damage and visual field loss. It is a complex optic neuropathy of genetically heterogeneity which can lead to irreversible blindness. The visual field loss is a late manifestation symptom, therefore it is not a reliable symptom to detect glaucoma in its early stages. It is the second biggest cause of blindness worldwide, responsible for 12% of all the cases of complete vision loss, while cataracts are responsible for 48% of reversible blindness worldwide. A positive family history plays an important role as a risk factor for primary openangle glaucoma development. This is the most common form of glaucoma and it typically occurs after 40 years old of age. If the disease is neither detected nor treated properly the risk of blindness is higher. Patients with a positive family history or patients with mutations in genes that are known to be associated with glaucoma should have medical attention in order to prevent later complications. In this way it is extremely important to seek new genes that could be related to glaucoma. Up to this time three genes have been associated with primary open-angle glaucoma, the myocilin gene (MYOC), the optineurin gene (OPTN) and the repeat domain 36 gene (WDR36). The CYP1A1 gene, located at 15q22-q24, encodes an enzyme which is involved in the conversion of chemical substances into highly reactive species leading to unwanted cell damage, cell death or mutation. The m1 polimorphism is related to a high rate of enzyme activity and it comprises increased lung cancer susceptibility. The objective of this paper is to analyze the correlation of 100 patients with primary open-angle glaucoma and 52 normal controls by the RFLP method (Restriction Fragment Length polymorphism). The frequency of the homozygous wild-type (w1/w1) of CYP1A1 gene among patients with primary open-angle glaucoma (n=100) was 16%, for the genotype w1/m1 the frequency of was 77% and for m1/m1 it was 7%. Among the control group (n=52) the frequency of the homozygous wild-type (w1/w1) of CYP1A1 gene was 54%, the frequency of w1/m1 was 46% and m1/m1 was 0%. The qui-square test ( 2) considered the result statistically significant (P<0,0001), and this suggests that the CYP1A1m1 polymorphism is associated with primary open-angle glaucoma.