Researchers Kathleen Arnos, Ph.D., retired professor of biology and director of the Genetics Program at Gallaudet University, and Ian Krantz, M.D., attending physician in the Division of Genetics at the Children’s Hospital of Philadelphia, are pushing for increased genetic testing to identify the cause of hearing loss in patients, especially pediatric patients.
According to Kratz, “Hearing loss is one of the most genetically heterogeneous diagnoses in humans, with hundreds of genes that can each result in hearing loss when changed or mutated.”
While sequencing the first human genome took over 10 years and cost $1 billion, genome sequencing can now be performed in just a few days for under $1,000, making it more accessible to those who could benefit.
A genetic diagnosis of hearing loss can also “enable the clinician to counsel the patient regarding the expected progression of hearing loss and map out a strategy for follow-up testing and intervention, including devices, educational strategies, etc.,” according to Sherri Jones, Ph.D., Chair of the Department of Special Education and Communication Disorders at University of Nebraska-Lincoln.
Genetic sequencing can be especially advantageous for newborns who exhibit symptoms of hearing loss; Arnos and Krantz named several examples of families who benefited.
One twelve-year-old boy had bilateral sensorineural hearing loss and also experienced vision and balance problems. Full genome sequencing revealed he had a rare recessive disorder called Brown-Vialetto-Van Laere syndrome. This disorder presents in childhood with hearing loss, but left untreated, it can progress to more severe neurologic difficulties. The child’s younger sister also tested positive, though she was asymptomatic, and both children were started on medication to halt the boy’s progression and prevent symptoms in his sister.
Another example is a four-month-old girl who was referred to an audiologist after failing her newborn hearing screening. She was diagnosed with profound sensorineural hearing loss, and genetic testing revealed Jervell and Large-Nielsen syndrome, which can cause hearing loss and heart arrhythmia. The child was then treated for hearing loss and referred to a cardiologist.
“There is no doubt that ensuring that genetic testing is more consistently used with audiologic newborn hearing screening will improve identification and outcomes of newborns with hearing loss,” Arnos said. “Clearly genetic testing and evaluation has become part of the diagnostic process of a child with hearing loss.”
“Someday in the future, when all newborns are screened for these types of genetic changes, we may be able to prevent these types of treatable forms of hearing loss from happening,” Krantz added.
If you or a loved one is experiencing difficulty with hearing or balance, call 863-386-9111 to schedule a visit with an audiologist today. These medical practitioners can help you identity any hearing symptoms that may be linked to broader health issues, and ensure you have complete information about your health.