Investigation of DAZ and RBMY1 gene expression in human testis by quantitative real-time PCR

This study developed quantitative real-time PCR assays for the DAZ and RBMY1 genes to determine the copy number of RNA extracted from testicular biopsies from a cohort of normospermic controls (n=6) and azoospermic males (n=17) including two males with Y-chromosome microdeletions (AZFc and AZFb + c). All patients underwent testicular sperm extraction (TESE) for intracytoplasmic sperm injection (ICSI). Forty percent of the azoospermic cohort showed a significant reduction in the copies of at least one of the genes (DAZ P=0.003; RBMY1 P=0.009). The histopathology of these patients ranged from Sertoli cell only (SCO) to severe hypospermatogenesis with interstitial fibrosis. The patient with the AZFb + c deletion lacked expression of DAZ and RBMY1 and had a histopathology of SCO. The patient with the AZFc deletion had reduced expression of RBMY1 and no DAZ expression with a histopathology of spermatocyte arrest. The quantitative real-time PCR assays for DAZ and RBMY1 gave positive predictive values of 78% and 70%, respectively for the recovery of sperm from testicular biopsy.