Genetic Hearing Loss Testing

Project Details

Project Background:
Congenital hearing loss is the most frequent birth defect in the United States, affecting about 3 newborn infants per 1,000 births. The term congenital hearing loss implies that the hearing loss is present at birth. It can include hereditary hearing loss or hearing loss due to other factors present either in utero (prenatal) or at the time of birth. About 95% of all newborns in the U.S. are screened for hearing loss, however, about twice as many young children have later-onset hearing loss, resulting in many children not getting identified during the newborn screening procedure.

It is estimated that 50% of congenital and late-onset hearing loss is caused by well-known genetic mutations and another 20% is estimated to be caused by congenital cytomegalovirus infection (CMV). The Connexion 26, deletion 35G gene has already been identified in the search for genetic causes of deafness, but testing for it requires expensive DNA sequencing.

A sensitive, accurate and reasonably priced test for genetic mutations and CMV infection would significantly improve the detection of early hearing loss. Because 30% of genetic hearing loss is caused by a single disease or condition (syndromic), testing for the most common mutations during the newborn period would also improve the chances of detecting genetic syndrome associations.

Research Focus:
The goal of this research project is to develop a genetic testing procedure that can be used in hospital laboratories to detect the most common genetic mutations that cause hearing loss in infants and young children. The most common genetic mutation causing hearing loss is very difficult to detect by current genetic testing and involves DNA sequencing which costs over $300 per sample.

This research project will use new advanced technology to see if it is possible to test this mutation for about $50 per sample. Such inexpensive testing will allow for all newborn babies to be tested and can have an immediate impact in the early neurodevelopment of a child by allowing for the placement of hearing assistance technology.