CATSPER2 and deafness: Three unrelated cases with bilateral, symmetrical, postlingual, moderate and stable HL (33416, 37112 and 37439) presented biallelic contiguous-gene deletions at chromosome 15q15.3 that included both CATSPER2 and STRC. This deletion causes deafness–infertility syndrome (DIS) in males due to CATSPER haploinsufficiency results in sperm abnormalities [78].