The contribution of genetic variations of airyl hydrocarbon receptor pathway genes to male factor infertility

Objective: To determine whether the polymorphisms in aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor repressor (AHRR), and aryl hydrocarbon receptor nuclear translocator (ARNT) genes are associated with male factor infertility. Design: An association study. Setting: University research laboratory and andrology clinic. Patient(s): The subjects were infertile Estonian men (n = 112) with azoospermia or oligozoospermia and controls (n = 212) with normal sperm parameters. Intervention(s): Blood samples were obtained for DNA extraction and genotyping. Main Outcome Measure(s): AHR (Arg554Lys), AHRR (Pro 185Ala), and ARNT (G/C allele) polymorphisms were genotyped using allele-specific polymerase chain reaction. Allele and genotype frequencies were compared between infertile men and controls and separately in the normozoospermia, oligozoospermia, and azoospermia groups. Result(s): The AHRR Ala185Ala genotype was implicated in susceptibility to male factor infertility. Ala/Ala genotype frequency increased in the following order: normozoospermia (18.0%), oligozoospermia (26.0%), azoospermia (42.1 %). Allele and genotype frequencies of AHR and ARNT polymorphisms were similar between cases and controls. Conclusion(s): We demonstrated that the AHRR Pro185Ala polymorphism contributed to a predisposition to male factor infertility in the Estonian population. A greater prevalence of the Ala/Ala genotype was found among infertile patients.