Objectives: The DFNA5 gene was identified in 1998 as a gene that causes an autosomal dominant form of hearing impairment. Five different DFNA5 mutations have been found; each results in skipping of exon 8 at the messenger RNA level. This finding indicates that DFNA5-associated hearing loss is attributable to a highly specific gain-of-function mutation. Interestingly, later reports revealed that DFNA5 also plays a role in tumor biology.
Methods: Recent data have shed more light on the biological function of DFNA5. Through a literature search, the current knowledge of this gene is reviewed.
Results: DFNA5 is the first gene for monogenic deafness that is known to involve apoptosis as a disease mechanism--a mechanism that was shown to be involved in frequent types of hearing loss caused by age, noise, or drugs. In line with its apoptosis-inducing properties, DFNA5 is a tumor suppressor gene with an important role in major types of tumors.
Conclusions: DFNA5 is a tumor suppressor gene that is involved in apoptosis pathways and as such performs a basic role in cell survival. In view of the known role of apoptosis in several forms of hearing loss, DFNA5 may be a player in the underlying disease mechanisms.