Non-invasive genetic diagnosis of male infertility using spermatozoal RNA: KLHL10mutations in oligozoospermic patients impair homodimerization

Infertility affects an estimated 7% of men worldwide, nearly a quarter of whom are diagnosed as idiopathic. The genetic etiologies of idiopathic male infertility are unknown, partly due to lack of simple diagnostic techniques. Moreover, the transmission risk of such genetic defects to offspring born from assisted reproductive techniques is increasingly becoming a concern for physicians and infertile couples. We explored the feasibility of obtaining full-length mRNAs from transcriptionally inert human spermatozoa in semen as a noninvasive diagnostic tool for identifying germline mutations in candidate infertility-associated genes. The efficacy of reverse-transcription PCR on spermatozoal RNA from infertile patients with wide-ranging sperm concentrations varied between 91 and 99% for multiple haploid germ cell-expressed genes. Using this methodology, we identified seven oligozoospermic patients with missense and splicing mutations in the germ cell-specific gene, KLHL10. Three of 270 (1.1%) severely oligozoospermic patients (