Newly discovered gene mutation is linked to hereditary deafness

Researchers led by geneticists at the Miller School have discovered a new gene mutation that causes hearing loss. Their study, which focused on a large Turkish family in which six individuals have been affected by hereditary deafness, identified a mutated form of the gene FAM65B as a cause of sensorineural hearing loss.

The research also demonstrates that FAM65B is a previously unrecognized component of the inner ear that is required for hearing.

“Hearing loss is the most common human sensory problem,” said Tekin. “We hope that identifying a new genetic cause of this disorder will lead to a better understanding of the molecular components of normal hearing.”

Hearing loss, which affects approximately 1 in 500 newborns, most often results from mutations of single genes that perform specific functions in the inner ear, where sound waves are converted to electrical signals. This process originates in the stereocilia — “hairs” projecting from cochlear hair cells that interconnect to form the hair bundle. Most of the approximately 50 previously identified hair bundle proteins are the products of genes that, when mutated, lead to hearing loss.

Researchers in this study, who conducted a genetic analysis of the subject family, identified a mutated form of FAM65B — a protein previously unassociated with hearing — as the cause. Further characterization of the protein product of FAM65B in rodents and zebrafish has confirmed the findings of the family study. Miller School of Medicine