What Happens in Heredity of Baldness

Baldness can be inherited. That means it can be passed on from one generation to another through genes. What exactly happens in the heredity of baldness?

The genetics of baldness is not yet fully understood but however the trait has been linked to a gene that is located on the X sex chromosome. These gene located on the X chromosome is responsible for causing the release of sex hormone binding globulin (SHBG). SHBG is responsible for binding with the sex hormones so that they do not go on to react with hair follicles and cause hair loss. When this gene undergoes mutation the body loses the ability to form sufficient amounts of SHBG this then allows the sex hormones to freely speculate and cause hair follicles to shrink. In males the absence of SHBG results in increased dihydrotestosterone (DHT) which causes balding. SHBG binds onto testosterone thus masking it away from an enzyme 5-alpha-reductase which readily converts it to DHT.

As a result of increased DHT formation due to the body's failure to produce sufficient amounts of SHBG hair follicles begin to shrink. This is so for DHT constricts the blood vessels that supply hair follicles. As the concentration increases more and more hair follicles continue to shrink some will start to die and hair patches become visible.

According to genetics, a male child will inherit an X chromosome from his mother and a Y chromosome from his father. This means that a male child will more likely become bald if his mother carries a baldness gene on one of her X chromosomes. Since the father only donates a Y chromosome to the son if the son is to become bald the bald gene would have descended from the mother's line. On the other hand a female child gets an X chromosome from the father and an X chromosome from the mother. This means that if the father is bald he is going to pass on the baldness gene to his daughter. However since she has two X chromosomes a mutation on one chromosome will not significantly affect the production of SHBG so she will not show any signs of male pattern baldness at all. This is one of the reasons why this kind of inherited baldness is only common in men than in women. Now when this woman that carries a baldness gene on one of her chromosomes marries, she has a 50% chance of passing on the baldness gene to her son. If her son gets the X chromosome that carries the baldness gene, he will show signs of male pattern baldness at a later age.

This is how genetics plays a role in baldness. Although balding can be genetically predetermined, its onset can be slowed down or completely avoided through the use of some baldness drugs that are available on the market. Some of these drugs inhibit the enzyme that form DHT, while some of them work on increasing the amount of oxygen and nutrients that reach hair follicles, all of which increase hair growth.