Inherited form of hearing loss stems from gen...( ANN ARBOR Mich. Pat Phalin learned ...),Health

ANN ARBOR, Mich. Pat Phalin learned she had hearing loss at 30, when she volunteered to give hearing tests at her local school. The pupils heard sounds she could not hear.

Her husband Larry, a genealogy enthusiast, saw a pattern in his wife's family history. Her mother, grandfather and great-grandfather had severe hearing loss as adults. One of the Phalins' children had hearing problems before he reached school age.

The hearing loss must be hereditary, Larry Phalin thought, though his wife's family didn't seem to realize it. "They blamed it on everything else under the sun: They worked in loud factories, they listened to loud music. One got hit by a tractor," he says.

Phalin, who lives near Chicago, heard 14 years ago that scientists were seeking families for studies of hereditary hearing loss. He got in touch with Marci Lesperance, M.D., now a hearing researcher at the University of Michigan Health System.

That contact sent Lesperance and her colleagues on a decade-long search. In 2001, her lab identified chromosome 12 as the one containing the responsible gene. Finally, after considering dozens of genes on this chromosome that could possibly play a role, they were able to identify one gene mutation that explains a previously unknown form of hereditary hearing loss.

In results published online today in the American Journal of Hearing Genetics, Lesperance and researchers in Iowa, France and Germany report they have identified a mutation in a gene, SLC17A8, that accounts for a form of hearing loss that diminishes one's ability to hear high-frequency sounds. The severity of the mutation's effects varies among individuals. The loss may occur early or later in life.

The researchers show that the mutation accounts for hearing loss in the Phalin family and another unrelated extended family in Iowa. Since the exact mutation occurs in two families that appear completely unrelated, the mutation may be an
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