Autosomal Recessive Inheritance
Read this page to find out how parents with normal hearing can have a child with genetic hearing loss.
You might think, “How can my child have a genetic hearing loss if both his father and I have normal hearing?”
Very often when there is genetic hearing loss, both parents have normal hearing. They may not even know of anyone in their families with hearing loss. This is possible when each parent has just one recessive gene for hearing loss. If 1 of their children gets 2 recessive genes (1 from each parent), he would have hearing loss.
Here’s a picture that shows how it works. In this picture the small “d” stands for the recessive gene for hearing loss. The large “D” stands for the dominant gene, which means no hearing loss. Each parent has “Dd,” which means no hearing loss. A child would only have hearing loss if he got “dd.” Each child has a 1 in 4 chance of getting dd, and having hearing loss.
How can my child’s hearing loss be genetic if there are no other people with hearing loss in our families?
A parent with hearing loss could also have the recessive gene.
Recessive genes that cause hearing loss
Many genetics clinics will test for the connexin 26 gene mutation. There are also many other recessive genes that can cause hearing loss. But there aren’t tests for most of these genes. So if your child doesn’t have the connexin 26 gene mutation, you may not find out what is causing his hearing loss.
If you think you might want to find out if your child has genetic hearing loss, read more about getting genetic counseling testing.