Deafness, Congenital, with Onychodystrophy, Autosomal Dominant, also known as ddod syndrome, is related to deafness, onychodystrophy, osteodystrophy, impaired intellectual development, and seizures syndrome and nail disorder, nonsyndromic congenital, 9. An important gene associated with Deafness, Congenital, with Onychodystrophy, Autosomal Dominant is ATP6V1B2 (ATPase H+ Transporting V1 Subunit B2). Affiliated tissues include skin and eye, and related phenotypes are severe sensorineural hearing impairment and absent fingernail