CATSPER-Related Male Infertility – RETIRED CHAPTER, FOR HISTORICAL REFERENCE ONLY

NOTE: THIS PUBLICATION HAS BEEN RETIRED. THIS ARCHIVAL VERSION IS FOR HISTORICAL REFERENCE ONLY, AND THE INFORMATION MAY BE OUT OF DATE.

Clinical characteristics: CATSPER-related male infertility results from abnormalities in sperm and can be either CATSPER-related nonsyndromic male infertility (NSMI) or the deafness-infertility syndrome (DIS) when associated with non-progressive prelingual sensorineural hearing loss. Males with NSMI have infertility while females have no symptoms. Males with DIS have both infertility and hearing loss, while females have only hearing loss. Routine semen analysis typically identifies abnormalities in sperm number, morphology, and motility. Otologic examination and audiologic assessment can identify hearing loss.

Diagnosis/testing: The diagnosis of CATSPER-related NSMI is established in males by the identification of biallelic pathogenic variants in CATSPER1. The diagnosis of DIS is established in both males and females by the identification of biallelic contiguous-gene deletions at chromosome 15q15.3 that includes both CATSPER2 and STRC.

Management: Treatment of manifestations: For infertile males with DIS or CATSPER-related NSMI, assisted reproductive technologies such as intracytoplasmic sperm injection are likely to be an effective fertility option. For males with DIS, treatment of hearing loss is best achieved by fitting hearing aids for amplification and special educational assistance for school-age children.

Agents/circumstances to avoid: For individuals with DIS, exposure to loud noise.

Evaluation of relatives at risk: For sibs at risk for DIS, audiologic testing in infancy or early childhood to enable early management of hearing loss.

Genetic counseling: CATSPER-related NSMI and DIS are inherited in an autosomal recessive manner. When both parents are carriers for pathogenic variants, each child has a 25% chance of inheriting both pathogenic variants, a 50% chance of inheriting one pathogenic variant and being an asymptomatic carrier, and a 25% chance of inheriting neither pathogenic variant. Males who inherit two CATSPER1 pathogenic variants will be infertile; females who inherit two CATSPER1 pathogenic variants will have no signs/symptoms. Males who inherit two CATSPER2-STRC deletions will be infertile and deaf; females who inherit two CATSPER2-STRC deletions will be deaf. If the pathogenic variants have been identified in an affected family member, prenatal testing for at-risk pregnancies is possible through laboratories offering either prenatal testing for the gene of interest or custom testing.