Genetic cause of hearing loss in aging

Researchers at Indiana University School of Medicine have taken a step toward understanding the genetics that make people more susceptible to the loss of hearing as they age.

In a study of 50 pairs of fraternal twins with hearing loss, the scientists uncovered evidence linking the hearing loss to a particular region of DNA that previously was tied to a hereditary form of progressive deafness that begins much earlier in life.

The work is believed to be the first genomic screening in search of genes associated with hearing loss using a sample of elderly people drawn from the general population. The 50 sets of twins were drawn from a group of twins who are veterans of World War II and the Korean War.

The results suggest "that this region may contain an important locus for hearing loss in the general population," said Terry E. Reed, Ph.D., professor of medical and molecular genetics at the IU School of Medicine.

The region of DNA identified by the IU study, a section of chromosome 3 named DFNA18, was implicated in a 2001 study of hereditary deafness in a large German family. It's possible the two studies are pointing to the same gene or genes, with variation in the genes resulting in differences in susceptibility to hearing loss, Dr. Reed said.