A genetic reason has been identified by researchers as being a cause of hair loss.

To make their discovery, Angela M. Christiano, Ph.D., FACMG, a researcher involved in the work from the Departments of Dermatology and Genetics and Development at the Columbia University College of Physicians and Surgeons in New York, NY, and colleagues defined the histone demethylase function of the human hairless gene, both in vitro and using cultured human cells.
When the hairless protein was mixed with specific histone substrates under defined reaction conditions, the hairless protein causes a reduction in the level of methylation modification of the histone substrates.
Similarly, upon expression of normal hairless protein, but not a mutant form of the hairless protein, researchers observed a drastic loss of histone methylation in human cells. This suggests that this may be the "on/off" switch for hair growth as well as a promising target for some types of skin disease.
The study has been published in the The FASEB Journal.
Source-ANI