March 14, 2013 — Researchers at the Medical College of Wisconsin in Milwaukee, Wisconsin, have received a grant from the American Hearing Research Foundation to conduct a pilot study of genetic hearing screening for newborns at the Children’s Hospital of Wisconsin to ensure the test can be performed and results shared with the parents in a timely and meaningful way. The ultimate goal is for the genetic hearing screening to become a standard part of newborn testing at hospitals throughout the United States.
Christina L. Runge, PhD, Associate Professor, Otolaryngology & Communication Sciences and Physiology at the Medical College of Wisconsin, Milwaukee, and colleagues will investigate the feasibility of a multi-institutional, multi-disciplinary genetic hearing screening program for newborns. The screening will look for the most common genetic markers known to cause hearing loss at birth or predispose children to permanent hearing loss from environmental factors. To watch a video about the research, go to the AHRF’s YouTube page.
Congenital hearing loss affects approximately one in 1,000 babies born in the United States each year, and it is estimated that half of the cases are genetic, or inherited. Since 2009, universal screening of newborns for hearing loss has been standard in all 50 states, and currently 97% of newborns are screened for hearing loss at the time of birth by measuring an infant’s responses to sound stimuli. However, these tests are only able to identify hearing loss present at the time of the screening, and they do not provide information about the cause of hearing loss. Several forms of hearing loss develop later in life, but so far, children at risk for these kinds of inherited hearing loss are not routinely tested and identified before the hearing problems start. By developing an effective protocol to genetically test newborns for mutations known to contribute to hearing loss at birth or later in life, appropriate follow up procedures, interventions and therapies can be started earlier in children who are at risk.
“The genetic markers of hearing loss we test for cause progressive and profound hearing loss, some of which would not necessarily be caught by the newborn physiological hearing screening performed soon after birth. Even if hearing loss was identified this way, we would not know the cause. By testing for these markers, we could have more information that would help us make the most appropriate treatment recommendations for the child. For example, we may identify children who might be candidates for treatments like cochlear implants. There is a relationship between the age of implantation and the ability to develop language skills; therefore, the earlier we can identify these children to get them involved in therapy and fully assess their treatment options, the better,” says Dr. Runge.
The screening will look for the most common mutations linked to congenital hearing loss and those that predispose patients to permanent hearing loss from environmental causes, such as certain ototoxic medications (medications that damage hearing cells in the inner ear). “It is well known that people who carry a specific genetic mutation are much more susceptible to medication-induced hearing loss,” says Dr. Runge. “Some antibiotics used to treat serious illnesses are known to cause significant permanent hearing loss, so knowing whether you have this genetic marker can be critical for your health care. A physician may be able to use a different antibiotic and hearing would be preserved.”