Introduction: Autosomal recessive syndromic hearing loss that results from contiguous gene deletions is uncommon. We describe three families with a novel syndrome characterized by deafness and infertility.
Methods: The families were ascertained through a genetics clinic at The Welfare Science and Rehabilitation University in Iran. Linkage to chromosome 15q15.3 was established by a genome-wide scan. Candidate genes in the linked region were screened by direct sequencing. To define deletion breakpoints, we used site-specific nucleotide dosage analysis.
Results: The families do not share identical deletions, although in each family the deleted region of chromosome 15q15.3 is about 100 kb and involves four genes -KIAA0377, CKMT1B, STRC and CATSPER2 - each of which has a telomeric duplicate.
Discussion: Deafness-Infertility Syndrome (DIS) is caused by large contiguous gene deletions of chromosome 15q15.3. A large tandem repeat in this region underlies the mechanism by which these deletions occur. The deleted genes include CATSPER2 and STRC, which are expressed in sperm and the inner ear respectively, consistent with the phenotype in affected persons.
- Deafness-Infertility Syndrome (DIS)
- contiguous gene deletion
- syndromic hearing loss