Genetic factors of predisposition to endometriosis and response to its treatment

: The relative frequencies of the normal (+) and null (0) alleles of the glutathione-S-transferase M1 (GSTM1) gene, as well as those of the rapid (R) and slow (S) forms of N-acetyl transferase 2 (NAT-2), were studied in the Russian and French populations and in endometriosis (EM) patients. In the total Russian and French populations, the proportions of homozygotes for deletion in gene GstM1 (0/0) were 42.2 and 45.8%, respectively, whereas in Russian and French EM patients, these values were 58.6 and 76.9%, respectively. The differences in these proportions between the total population and subjects with EM were significant at the confidence levels of 0.98 (chi 2 = 5.45; P < 0.02) and 0.90 (chi 2 = 3.01; P < 0.1) for the French and Russian populations, respectively. The frequencies of allele S of the Nat-2 gene were also similar in the Russian and French populations (60 and 63.1%, respectively), with these frequencies being somewhat higher in EM patients (71.2 and 77.7%, respectively). In Russians, the proportion of EM patients who were homozygous for the R form of NAT-2 (R/R) was significantly lower (chi 2 = 5.1). Forty-three of the patients with external genital EM received complex treatment with the use of the interferon inducer Cyclopheron. In 17 patients, a pronounced positive dynamics was observed, and 29 patients exhibited an increased resistance to the immunomodulating therapy. These groups comprised 1 and 25 GstM1 0/0 homozygotes, respectively; the number of patients with the slow NAT-2 form was 13 (7 S/S and 6 S/R genotypes) and 29 (20 S/S and 9 S/R genotypes), respectively. The obtained data indicate that the GstM1 and Nat-2 genes are involved in the EM pathogenesis. Therefore, molecular screening for the GstM1 0 and Nat-2 S alleles would be a good prognostic test when prescribing the postoperative treatment for EM and predicting its effectiveness.