The Genetics of Hearing Loss: An Overview

Everybody knows that noise, injuries and selected diseases can result in hearing loss, but are your genes involved? Yes. Hearing loss can be genetic. Believe it or not, industry professionals agree that most hearing loss is caused by some form of genetic abnormality. Additionally, developmental experts consider genetic hearing loss to be the most common birth defect in developed countries.

Essential genetics. Genes are essentially bits of code that make up our DNA and tell our bodies how to function and how to look. Researchers have identified over 100 genes that can impact hearing. Hearing loss can result from any one of these genes being absent or altered. Parental genes are passed to children, so any abnormal gene sequences which cause hearing loss are passed down.

Varieties of genetic hearing loss. Some types of hereditary hearing loss can visibly impact the outer ear, while other varieties just influence hearing in the inner ear. Conductive, sensorineural or mixed hearing loss may arise. Note that, genetic hearing loss can reveal itself at birth or later in life. One of the most common conditions to affect hearing is Usher syndrome, a condition that is thought to affect over half of deaf-blind individuals as reported by the National Institutes of Health. Waardenburg syndrome is another common condition that affects hearing in the inner ear but also causes streaks of white hair, pale skin, and light or multi-colored eyes.

The good news about genetic hearing losses. Thankfully, hearing loss isn’t necessarily passed from parent to child. The genes that cause hearing loss are usually recessive and therefore frequently don’t result in any outward symptoms because the child has received a normal copy from the other parent. Because there are hundreds of distinct genes involved in hearing loss, even if both parents are hearing impaired, their kids may not be since the parent’s hearing loss can have different root causes. For moms and dads concerned about a family history of hearing loss, genetic testing and counseling from an expert is advised.