POLYMORPHISM OF GSTM1 AND GSTT1 GENES IN WORKERS OF FERROUS METALLURGY WITH PROFESSIONAL FLUOROSIS

Abstract

The aim of the present work was to study genetic risk factors for the development of professional fluorosis in workers of Novokuznetsk aluminum factory, the presence of which is associated with the risk of professional dental fluorosis and resistance to it. The study involved 79 male workers of Novokuznetsk aluminum factory Ltd. "RUSAL" of 35-60 years. The control group (212 people) consisted of healthy individuals working for the same company and without fluorosis. The material for the study were the venous blood samples. Polymorphism of null-alleles of genes encoding transferase phase 2 biotransformation of xenobiotics - GSTT1 and GSTM1 was studied. In this study DNA was isolated by phenolhloroformnym method performing polymerase chain reaction amplification products electrophoresed on agarose gel, and the products were visualized under ultraviolet light. The frequencies of alleles and genotypes in groups of patients and healthy subjects were compared using the χ² test with Yates correction for continuity. The association of different genotypes (or combinations thereof) was estimated by the magnitude of the disease odds ratio (OR). The frequencies of alleles and phenotypes in our sample were studied on an aluminum factory workers and were already comparable to previously published data on Russian Federation and Siberian federal district. Analysis of differences in genotype frequencies between patients with fluorosis and those of the control group using χ² criteria and OR shows that the largest contribution to the risk of developing the disease is making by null-allele of the GSTT1 gene (GSTT1(-)), as well as the "double zero" - a combination of GSTT1(-) and GSTM1(-). On the other hand the holders GSTT1(+)) as well as combinations of genotypes GSTT1(+) / GSTM1(-) are the most resistant to this disease genotype. The obtained data can be used in the formation of risk groups for development of fluorosis, for timely diagnosis and prevention of loss of workers' health.