Certainly injury and illness can lead to hearing loss, but can genetics also contribute? The simple response to this question is ‚Yes. Genetic irregularities actually lay at the root of most types of hearing loss. In the developed world, hearing loss is regarded as the most common hereditary birth defect.
A quick lesson in genetics. They way your body looks and functions is controlled by the genetic code of your DNA – your genes. More than 100 different genes have been found that are associated with hearing loss. Hearing loss may result from any one of these genes being missing or modified. When a person having these abnormal gene sequences has a child, the abnormal gene or genes can be passed on to the child too.
Different kinds of genetic hearing loss. Some forms of inherited hearing loss can visibly affect the outer ear, while other forms just affect hearing in the inner ear. Conductive, sensorineural or mixed hearing loss may result. The hearing loss does not necessarily start at birth. It might have a later onset after a child has learned to speak (postlingual hearing loss). A few of the genetic conditions are prevalent enough to have names. For example, Usher syndrome impacts about 50 % of the deaf-blind population. Another named disorder that includes hearing loss is Waardenburg syndrome. Distinguishing characteristics include pale skin, a streak of white hair and light-colored eyes in addition to the hearing loss.
Is there any good news? While it’s true that parents with hearing loss genes may pass them on to their children, it doesn’t necessarily mean that the children will have a hearing problem. The genes that contribute to hearing loss are usually recessive and therefore frequently don’t lead to any outward symptoms because the child has received a normal copy from the other parent. It’s not unusual for the children of hearing impaired parents to have normal hearing. Because there are hundreds of genes involved in hearing, it is more likely than not that the parental hearing losses don’t share exactly the same cause. Genetic screening is available for those who suspect hearing loss is in their family genes.