Deafness-infertility syndrome

Other Names: Sensorineural deafness and male infertility

Sensorineural deafness and male infertility is a condition characterized by hearing loss and an inability to father children. Affected individuals have moderate to severe sensorineural hearing loss, which is caused by abnormalities in the inner ear. The hearing loss is typically diagnosed in early childhood and does not worsen over time. Males with this condition produce sperm that have decreased movement (motility), causing affected males to be infertile.

Epidemiology

The prevalence of sensorineural deafness and male infertility is unknown.

Cause

Sensorineural deafness and male infertility is caused by a deletion of genetic material on the long (q) arm of chromosome 15. The signs and symptoms of sensorineural deafness and male infertility are related to the loss of multiple genes in this region. The size of the deletion varies among affected individuals. Researchers have determined that the loss of a particular gene on chromosome 15, the STRC gene, is responsible for hearing loss in affected individuals. The loss of another gene, CATSPER2, in the same region of chromosome 15 is responsible for the sperm abnormalities and infertility in affected males. Researchers are working to determine how the loss of additional genes in the deleted region affects people with sensorineural deafness and male infertility.

Inheritance

Autosomal recessive inheritance, a 25% chance

Sensorineural deafness and male infertility is inherited in an autosomal recessive pattern, which means both copies of chromosome 15 in each cell have a deletion. The parents of an individual with sensorineural deafness and male infertility each carry one copy of the chromosome 15 deletion, but they do not show symptoms of the condition.

Males with two chromosome 15 deletions in each cell have sensorineural deafness and infertility. Females with two chromosome 15 deletions in each cell have sensorineural deafness as their only symptom because the CATSPER2 gene deletions affect sperm function, and women do not produce sperm.

Signs and symptoms

Affected individuals have moderate to severe sensorineural hearing loss, which is caused by abnormalities in the inner ear. The hearing loss is typically diagnosed in early childhood and does not worsen over time. Males with this condition produce sperm that have decreased movement (motility), causing affected males to be infertile. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Azoospermia(Absent sperm in semen)
• Male infertility
• Sensorineural hearing impairment

Diagnosis

Routine semen analysis typically identifies abnormalities in sperm number, morphology, and motility. Otologic examination and audiologic assessment can identify hearing loss.

Treatment

Infertility. No available treatment can reverse the morphologic and/or motility defects asthenospermia or asthenoteratospermia (low motility with increased number of abnormal forms). For infertile males, one option is to bypass these morphologic and motility abnormalities using assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI) . This approach has been used successfully in males with DIS.

Deafness. For males and females with DIS, treatment of hearing loss is best achieved by fitting hearing aids for amplification. For school-age children or adolescents, special educational assistance may also be warranted and, where possible, should be offered.

NIH genetic and rare disease info

• NIH info on Deafness-infertility syndrome

Deafness-infertility syndrome is a rare disease.