Signs of Hearing Loss
Types of Hearing Loss
Causes of Hearing Loss
Genetics of Hearing Loss
Can My Child Hear?
Other Ways of Inheriting Hearing Loss
Read this page to find out about less common ways hearing loss can be inherited.
X-linked hearing loss
X-linked recessive inheritance causes hearing loss in only a small number (about 3%) of people with hearing loss.
- With X-linked recessive inheritance, only boys are affected.
- Girls can be carriers of the gene. That means they could pass it on to their sons in the future.
- If a mother is a carrier of the hearing loss gene, her sons will have a 50% chance of having hearing loss.
- If a mother is a carrier of the hearing loss gene, none of her daughters will have hearing loss. But half of them will be carriers.
- X-linked types of hearing loss can be a mix of conductive and sensorineural hearing loss.
X-linked means that the gene is on one of the sex chromosomes. Here’s how it works:
One of the pairs of chromosome is called the sex chromosomes. Males have an X and a Y chromosome (written XY). Females have two X chromosomes (written XX).
If there is a recessive gene for hearing loss on only one of the mother’s X chromosomes, she will have normal hearing. She would be called a “carrier.” Half of her children will get the hearing loss gene. Her daughters will get the normal gene on the X chromosome from their father. Sons won’t have a second X chromosome because they will have gotten the Y chromosome from their father. So they will have hearing loss even though they have only one copy.
In this picture the mother is a carrier of an X-linked hearing loss gene called Xd. Only her sons who get the Xd from her and the Y from their father will have hearing loss.
X-Linked Recessive Inheritance
Mitochondria (mi-toe-KON-dree-a) are parts of a cell that help produce energy. They have their own set of genes. Changes in mitochondrial genes can sometimes cause hearing loss.
- Mitochondria are passed from mother to child in the egg from the mother. Sperm from the father don’t pass mitochondria to the baby.
- Since mitochondria only come from the mother, only mothers can pass mitochondrial traits to their children.
- Mitochondrial deafness can be either syndromic or non-syndromic.
- One type of mitochondrial mutation (called A1555G) makes a person more likely to lose hearing after taking some antibiotics.
- Other types of mitochondrial mutations can cause hearing loss along with diabetes or neuromuscular (NUR-oh-mus-kew-lar) disease.
- Mitochondrial mutations are the cause of hearing loss only about 2% of the time.