Genetic Variation in the Testis-Specific HASPIN Gene Encoding a Serine/Threonine Protein Kinase in Infertile Japanese Males

HASPIN is a serine/threonine protein kinase predominantly expressed during spermatogenesis and localized in the nucleus. The HASPIN gene is conserved from yeast to mammals and plants. To investigate any possible associations between HASPIN polymorphisms and impaired spermatogenesis in Japanese males, we screened for mutations in the HASPIN coding sequence (CDS) using DNA from 282 sterile male patients and 262 fertile male volunteers. Polymorphisms were found at 10 positions within the HASPIN CDS. Among these 10 polymorphisms, 5 were found only in the infertile group, 3 of which were nonsynonymous. These polymorphisms found only in the infertile patients may be a cause of male infertility and thus valuable candidates for further study of this condition.