Up to date, a total of four mutations in DFNA5 have been reported to lead to hearing impairment, all of them result in skipping of exon 8 at the mRNA level.
Up to date, a total of four mutations in DFNA5 have been reported to lead to hearing impairment, all of them result in skipping of exon 8 at the mRNA level.
The transfection experiments in mammalian cell lines support our hypothesis that the hearing impairment associated with DFNA5 is caused by a "gain of function" mutation and that mutant DFNA5 has a deleterious new function.
Because no other mutation in any other part of DFNA5 has ever been described, this finding might indicate that exon 8 of DFNA5 is indispensable for the development of hearing impairment.
Yeast cells tolerated expression of wild-type DFNA5, while expression of the mutant DFNA5 allele, which is responsible for nonsyndromic autosomal dominant hearing impairment, led to cell cycle arrest.