Endometriosis is a topical problem of contemporary medicine. It is the presence of endometrioid overgrowth outside the endometrium that may be inside the womb (internal endometriosis) or outside the womb (external endometriosis) [1,2]. Endometriosis occurs in 12-50% of women during their reproductive years [1-3]. Most patients suffer pain, about half suffer from infertility, and many suffer from abnormalities of endocrine and immune status [1-3]. Hereditary predisposition plays a very impor­tant role among the factors that may cause endometriosis and dictates the necessity to identify genetic markers asso­ciated with this disease [1,4,5]. This has stimulated inves­tigations into the role of genes of the xenobiotic detoxica­tion system (environmental genes) in the pathogenesis of endometriosis [4,5,7-11]. Our investigations have indi­cated an association of functionally inferior alleles of phase 2 xenobiotic detoxication with endometriosis.

      Arylamine N-acetyltransferases (NAT) control phase 2 by acetylating many xenobiotics. NAT1 and NAT2 genes are located at 8p23.1-p21.3 [12,13]. Both genes are polymorphic, and there exist a lot of point mutations in the gene coding regions. NAT2 is a constitutional enzyme, which is expressed in the two phenotypes: rapid acetylat­ing and slow acetylating. Polymorphism of the NAT2 gene results from mononucleotide substitutions [12] that reduce the gene expression and enzyme activity [13-15]. Different combinations of NAT2 alleles are associated with the different acetylation and with predisposition to several diseases [10,11,16-18].

      The aims of this study were to conduct a clinical and epidemiological analysis of endometriosis in Bashkorto­stan, to uncover the association of possible molecular and genetic markers for this disease with its nosologic forms and therapy effectiveness.