Steroid 5α-reductase 2 gene melting polymorphisms in male subjects with azoospermia or oligospermia

Objective: This study was designed to test the hypothesis that mutations in the gene for type 2 steroid 5α-reductase (SRD5A2) may be the cause of a phenotype characterized primarily by oligospermia or azoospermia. Study Design: Deoxyribonucleic acid from control subjects and subjects with oligospermia (n = 12) and azoospermia (n = 6) were evaluated for mutations in SRD5A2. Methods used for mutation analysis included polymerase chain reaction, Southern blotting, and denaturing gradient gel electrophoresis. Results: Denaturing gradient gel electrophoresis of all 5 amplified exons resulted in similar migration patterns in samples from both control and study subjects. Genomic deoxyribonucleic acid subjected to denaturing gradient gel electrophoresis after restriction digest revealed melting polymorphisms. Direct sequencing of the gene in a single patient with a unique melting polymorphism yielded a normal sequence. Conclusions: Melting polymorphisms for SRD5A2 were detected in a group of patients with oligospermia or azoospermia. Sequence analysis did not demonstrate functional mutations in the coding sequence of this gene. (Am J Obstet Gynecol 1999;180:1394-8.)