Association Between Endometriosis And Polymorphisms Of NAT2 Gene

BACKGROUNDEndometriosis is a common benign disease whose etiology is still unknown. However, there is increasing evidence that genetic susceptibility is a risk factor for the development of the disease. It is generally accepted that endometriosis is inherited as a complex genetic trait, like diabetes or asthma, in which multiple gene loci interact with each other and the environment to produce the disease phenotype. A number of candidate genes have been studied to date. Genes encode for enzymes involved in the metabolism and detoxification of toxins have also been studied, based on data suggesting that chronic exposure to dioxin is a risk factor for pathogenesis disease.An association between endometriosis and polymorphisms in N-acetyltransferase 2 (NAT2) gene has been reported in American (Bischoff et al, 1998), French women (Baranova et al, 1999) and UK population (Nakago et al, 2001). NAT2 is involved in the initial biotransformation metabolism of aromatic amines and hydrazines and catalyses the transfer of acetyl group from acetyl CoA to the nitrogenof the substrate. The NAT2 gene locus has been mapped to 8p21.3-23.1. Reduced NAT2 activity associated with Ml, M2, M3, may be an aetiological factor of endometriosis or the polymorphism may be in linkage disequilibrium with this disease susceptibility allele.The aim of this study is to determine whether the polymorphisms M1, M2, M3, are associated with endometriosis in Chinese population. Therefore, we may regard these mutations as the candidate marker for the diagnosis of endometriosis.MATERIALS AND METHODS1. Clinical specimen and DNA isolationGenomic DNA was extracted from blood lymphocytes of 75 Chinese women undergoing laproscopy and laprorectomy for endometriosis in Women's hospital, School of Medicine, Zhejiang University. The control group consisted of 80 women who underwent reananstomosis, sterility and treatment of ectopic pregnancy or leiomyoma without pelvic endometriosis and adenomyosis evidenced by laproscopy or laprorectomy.2. Polymerase chain reactionsPolymerase chain reactions (PCR) were performed in a system of total volume of 50 1 in a multiplex reaction. Amplification protocol consisted of: initial denature at 94℃ for 5 min, followed by 35 cycles of 94℃ for 1 min, 60℃ for 1 min, and 72 ℃ for 1 min, with a final elongation of 72℃ for 10 min.3. Detection of the Ml, M2, M3 polymorphismsFollowing PCR amplification, digestions of PCR products with the restriction enzyme Kpn I , Taq I and BamH I were carried out to detect the substitutions C481A, G590A, G857A respectively. The products of digestion were separated on 2% agarose gels, stained with ethidium bromide and visualized under ultraviolet light.4. Statistical analysisComparisons of frequency were analyzed using x2 analysis and confidence intervals.RESULTSNAT2 allele frequency and the genotype frequency had no significant difference between the endometriosis patients and controls.CONCLUSIONSThere is likely no association between the NAT2 gene polymorphism and endometriosis in Chinese women.