Rare X-Linked Non-Syndromic Sensorineural Deafness Type Dfn, also known as x-linked non-syndromic sensorineural hearing loss type dfn, is related to deafness, x-linked 6 and deafness, x-linked 1. An important gene associated with Rare X-Linked Non-Syndromic Sensorineural Deafness Type Dfn is COL4A6 (Collagen Type IV Alpha 6 Chain).