Occurrences of Genetic Hearing Loss

The human ear is a complex and amazing piece of craftsmanship. Deafness or hearing impairment can be caused by many types of infectious disease, injury, exposure to loud sounds or tumor. While any of these can cause deafness in young children, a frequent cause of childhood hearing impairment is a genetic disorder.

The conditions that cause genetic hearing loss are inherited from one or both parents. If family members suffer from a diagnosed disorder, a child’s doctor will want to eliminate that cause first by running the proper tests. Often, however, a child can suffer genetic hearing loss without the warning of previously affected family members.

Silent Inheritance

When a disorder causing genetic hearing loss is carried on a dominant gene, it will develop in every family member that carries the gene. Only one parent needs to pass it on and that parent will also have the disorder. If a disorder that leads to genetic hearing loss is carried on a recessive gene, both parents have to carry it and pass it to a child in order for that child to be affected.

If the child inherits the gene from only one parent, it will carry the gene and possibly pass it along to its own children but will not develop the disorder. There are two kinds of disorders that cause genetic hearing loss. Syndromic disorders lead to genetic hearing loss along with a group of other health problems.

The genetic hearing loss of the syndromic type is often determined by tests for one of the other health problems. Alport syndrome causes kidney problems; Usher syndrome features progressive blindness and Waardenburg syndrome presents skin pigment changes. All cause some degree of genetic hearing loss as well.

Most genetic hearing loss is nonsyndromic. The only evident health problem is the hearing loss. When hearing loss is determined to be genetic, medical specialists need to find out whether it is part of a syndrome in order to begin a timely treatment of other developing problems. Often, a genetic hearing loss can be helped with genetic testing.

When there are no symptoms except hearing loss and there are few if any family members with the same disorder, genetic testing can find information that can help predict whether the hearing loss will become worse over time, can help decide whether a cochlear implant would be helpful and aid the patient in making future reproductive choices. In addition, the information about the genetic hearing loss can lead to successful gene therapy when it becomes available.