P-70: Study of GTn-Repeat Expansion in Heme Oxygenase-1 Gene Promoter As Genetic Cause of Male Infertility

Background: The length of GT-repeats polymorphic region in the promoter of human Heme oxygenase-1 gene (HO-1) alters the level of its transcriptional activity in response to oxidative stresses. Decreased level of HO-1 protein in the seminal plasma has been reported to be associated with oligospermia and azoospermia in male infertility. This is the first study to investigate the association between GT-repeats expansion in promoter of HO-1 and male infertility. Materials and Methods: The allelic frequencies for different GT-repeats in the promoter of HO-1 gene were determined in 100 case and 100 normal control groups using PCR-PAGE, ABI fragment analysis genotyping and sequencing analysis. Results: All alleles were classified into S and L alleles.S alleles with < 27 specified as allele number 0 to 3 and L alleles > 27 repeats were specified as 4 to 6 alleles. The L allele frequency was significantly higher (54.5%) among case group than that in the normal controls (37.5%). Statistical analysis provide significant relationship between L alleles and male infertility (p<0.001). Conclusion: This study shows for the first time that GT-repeats expansion in promoter of the HO-1 gene is associated with oligospermia and azoospermia in male infertility among Iranian infertile cases.