Based on the two reports that recently appeared in the Nature Genetics journal, researchers were able to discover a new gene variation that is strongly associated with hair loss conditions. What's notable about the studies, however, is the fact that the two different studies showed that this hair loss gene variant can be inherited not just from the mother's side but also on the father's as well.



The Earlier Claims

It was long believed that hair loss - or rather the tendency to develop a hair loss condition - is inherited. Studies showed that genetics plays a vital role in the development of pattern baldness among men and women. This is because people who have a family history of hair loss conditions are more likely to develop baldness due to the presence of DHTs or dihydrotestosterone (DHT). In relation to the link between genetics and hair loss, it was also believed that hair loss genes can only be inherited from the mother's side.

In general, the idea that genetic susceptibility to hair loss comes from the mother's genes was first known during the 1916. The said idea was then supported in 2005 when German researchers were able to discover an AR (androgen-receptor) gene on the X chromosome of many men who had hair loss problems. Basically, men get a single X chromosome from the mother's side. As a result, men have a 50 percent chance of being genetically predisposed to go bald if their maternal grandfather has a hair loss problem.

Contrary to the Common Ideas…

Despite the fact that the AR gene is normally located on the X chromosome inherited from the mother, researchers also suspect that there are many other factors that contribute to the development of hair loss. This is because in some studies, some men who have the AR gene did not develop hair loss conditions. Moreover, in a study that was conducted in 2004, researchers discovered that men who had fathers with male pattern baldness were 2.5 times more at risk to develop baldness than men who had fathers without a baldness problem. This susceptibility to baldness was likely regardless of the hair condition of the respondent's maternal grandfathers.

In the two recent studies that were made, researchers examined the DNA samples from large groups of men that were diagnosed with male-pattern baldness. They tried to look for “genetic markers” that were present among the patients but were absent among men with abundant hair. Both groups of researchers were able to determine variations on chromosome 20.

Markus M. Noethen, a geneticist from the University of Bonn notes that humans get a copy of chromosome 20 from both of their parents. He then explains that “The gene variation for balding is neither dominant nor recessive, but additive”. Therefore, men who have a baldness affected copy of chromosome 20 will have a baldness susceptibility of 3.7 while those with two affected copies will have 6.1.