Alport Syndrome is a genetic disease characterized by progressive hearing loss, as well as kidney disease and eye abnormalities. In Alport syndrome, a mutation in one of the genes that encode for the structural protein type 4 collagen causes problems in how the protein is made and functions.
Why is hearing affected by Alport syndrome?
Type 4 collagen is important in forming the organ of Corti (part of the cochlea), the portion of the inner ear that transforms sounds into electrical signals sent to the brain via auditory nerves. Structural abnormalities caused by the mutations lead to hearing loss, which can develop into profound deafness in some patients.
Approximately 80% of boys with Alport syndrome will develop hearing loss, often by their teenage years. Hearing loss is less frequent in girls and generally occurs later in life.
Living with hearing loss
Hearing loss is never present at birth in people with Alport. Rather, signs of hearing loss typically start to appear in late childhood or early adolescence, often before kidney symptoms are detected. Patients will have difficulty hearing and understanding what people are saying, especially over background noise.
Not being able to hear can be devastating and isolating. It can make school difficult, and hearing loss in children has been linked to developmental and behavior problems. Many patients will be able to use hearing aids. Others may find learning a sign language to be helpful. It is recommended that children begin learning sign language as soon as their hearing loss is detected.
At school, hearing loss is usually first noticed as a child’s difficulty in hearing what the teacher is saying and following lessons. A hearing test, using headphones, should be performed to assess the range of sounds that a patient can hear.
Not all types of Alport syndrome cause hearing loss, but the progression of hearing loss can correlate with worsening of kidney problems, so it is recommended that patients get their hearing checked frequently.
Most Alport syndrome patients are good candidates for hearing aids. At this time, no treatment can slow or reverse the progression of hearing loss for Alport syndrome, though the Alport Syndrome Foundation is raising funds to support research into potential treatments.
A kidney transplant, if necessary because of damage was done to this organ by the disease, will not affect the progression of hearing loss.