Analysis of the AhR, ARNT, and AhRR gene polymorphisms: genetic contribution to endometriosis susceptibility and severity

OBJECTIVE: To explore whether polymorphisms in AhR, ARNT, and AhRR contribute to endometriosis susceptibility and severity. DESIGN: Case control study. SETTING: Hospital. PATIENT(S): One hundred thirty-eight Japanese women with or without endometriosis, diagnosed endoscopically. INTERVENTION(S): Endoscopic laparoscopy, with blood samples for genotyping obtained before the laparoscopic examination for genomic DNA extraction from peripheral leukocytes. MAIN OUTCOME MEASURE(S): AhR, ARNT, and AhRR polymorphisms were genotyped using real-time polymerase chain reaction (PCR) analysis. Odds ratios and 95% confidence intervals were calculated for AhR, ARNT, and AhRR genotypes to evaluate the risk of endometriosis. Associations between these polymorphisms and stage of endometriosis were also examined. RESULT(S): The C/G + G/G genotypes at codon 185 of AhRR showed a statistically significant association with risk of endometriosis (adjusted odds ratio, 2.53; 95% confidence interval, 1.16-5.55). Furthermore, a statistically significant trend associated the C/G + G/G genotypes with the clinical stage of endometriosis. No statistically significant association was observed between AhR codon 554 or ARNT codon 189 polymorphisms and endometriosis. CONCLUSION(S): AhRR codon 185 polymorphism was associated with susceptibility to and severity of endometriosis in Japanese women.