Exploring the Questions Behind Genes and Hereditary Hearing Loss
Most people understand—to some degree or other—that we all inherit certain traits and characteristics from our parents. We see it every day as we see children and grandchildren take on similarities of their parents and grandparents. The specifics of how our genes ebb and flow across generations are a little more complex, however, as all of our traits are not always external. People that experience hearing loss often wonder if this is hereditary and whether they will pass it on to their children or whether they got it from their parents. It can be hard to say, but there has been considerable research done on the topic.
So, let’s talk about genes and hearing.
Genetics of Hearing Loss & Common Statistics
Hearing loss is one of the most common sensory disorders. Studying hearing loss can get complicated because it’s not always hereditary. Many times, in fact, it is due to environmental conditions and exposure to loud noise or the aging process. According to the CDC, 50% to 60% of babies born with hearing loss have it from genetic causes and about 25% or more of hearing loss in babies is caused by environmental factors. So the total number of hearing loss cases is split between hereditary causes and environmental causes.
Other relevant statistics about hearing loss from the National Institute of Deafness and Other Communication Disorders:
- About 2 to 3 out of every 1,000 children are born with some level of hearing loss in one or both ears
- About 15% of American adults over the age of 18 report some trouble hearing
- More than 90% of deaf children are born to parents that have complete hearing capacity
The Intricate Gene Code
The study of genetics is complicated and has evolved considerably in the last few decades. Genes are the basic unit of inheritance. These units are passed on from generation to generation When put in simple terms genes are codes, or instructions, that instruct cells on how to work, grow and protect themselves. It is those instructions that indicate what color a person’s eyes will be or what color their hair is. There are codes in our genes that are relevant to hearing.
When a gene does not form in the way that it is supposed to, it is called a mutation. These gene mutations are what cause differences in people that are born with hearing loss, for example, or other types of conditions. It is not just one gene that is involved in hearing; there are many. These gene mutations might run in families or they might not.
Hearing Loss in Genes and How They Run in Families
The famous Mendel experiments provided the foundation for the principles of inheritance. One of the main conclusions was that an organism’s inner characteristics cannot be completely inferred by simply observing its outer characteristics. The three principles Mendel uncovered were:
- The law of dominance: This refers to dominant traits, which means they will always be present and visible in offspring.
- The law of independent assortment: This concept depicts the idea that alleles can be inherited independently because genes often reside on different chromosomes
- The law of segregation: Has to do with the way cells separate and how they may cause alleles to segregate from one another.
Mendel’s experiments essentially broke ground in understanding how hereditary traits can sometimes skip or “hide” between generations. Part of the understanding was that certain traits can exist in different alleles. Each parent provides their offspring with one allele for each different gene, that’s when traits become dominant or recessive. Recessive traits are the ones known to skip a generation and reappear a generation or two later.
Advances in the study of molecular biology have allowed the medical community to have a better understanding and have led to earlier interventions to help people with hearing loss.
The Cochlea and Hereditary Hearing Loss
The part of the ear that is responsible for the complex translation of vibrations into signals for the brain to interpret is a complex and specialized part of the body. This is the spiral-shaped bone that is found in the inner ear. Without the intricate functions of the cochlea, the brain would not be able to read and/or interpret the individual sound frequencies.
According to Science Daily, hereditary deafness can manifest in a variety of ways. It can cause deafness from birth or cause problems with hearing loss until about age forty. If a person receives a muted copy of a gene that indicates hearing loss, deafness can develop later in life.
Get Your Hearing Checked with a Trusted Hearing Specialist
Don’t suffer hearing loss alone. Here at Mission Hearing, we see a lot of cases of people that experience hearing loss early and late in life. Everyone’s situation is different and whether the hearing loss is hereditary or not, you still want to treat it appropriately to ensure you continue an active and productive lifestyle. Thanks to advancements in technology and a better understanding of the ear, a variety of hearing aids can aid people to help with their hearing.
Think you may be experiencing hearing loss? Call Mission Hearing today.