Congenital Hearing Loss (Cx26)
What is congenital hearing loss?
Congenital hearing loss (also called sensorineural hearing loss) is a type of permanent, inherited hearing loss that can range from mild to severe (total deafness). The Eli screen tests for one type of congenital hearing loss, caused by the body not properly producing a protein called connexin 26. This protein is required for sending noise and sound signals from the ear to the brain, along the auditory nerve. Babies who are born with congenital hearing loss due to problems with connexin 26 lose the ability to hear before they can learn to speak.
How common is congenital hearing loss?
Congenital hearing loss related to the connexin 26 protein affects about 1 in every 5,000 babies in the United States each year.
What can be done for congenital hearing loss?
Identifying this condition early makes it possible to start treating the symptoms of hearing loss, and helps to minimize the long term effects. For mild cases, hearing aids can be fitted to assist in hearing. When the hearing loss is considered to be severe, one option is to undergo surgery to implant a device called a cochlear implant. Cochlear implants are different from hearing aids. While hearing aids simply make sounds louder for the ear to pick up, cochlear implants actually do the work of transmitting sound signals directly to the brain.
How is congenital hearing loss inherited?
Congenital hearing loss is caused by changes in the GJB2 gene. It is a recessive inherited condition, which means that a person must inherit two altered copies of the GJB2 gene, one from each parent, in order to have the disease. People who have only one copy of the altered GJB2 gene are called carriers, and are not expected to have symptoms of the condition. If a baby is identified as a carrier for congenital hearing loss through Eli screening, genetic counseling and additional testing in the parents is recommended.