Researchers have found a normal role for a gene that causes two rare hair-loss disorders when it is disabled.Gone are the days when scientists were finding it diificult to treat ordinary baldness. So far, even with the new work, there is no evidence of a direct link between the hairless gene and typical baldness. In fact, this new study does not explain why the gene causes the rare hair-loss disorders when it malfunctions.
Accoeding to researchers, many types of hair loss probably share a similar biological mechanism, and understanding the hairless gene's function will help scientists figure that mechanism out. Previous work has shown that people who inherit a malfunctioning version of hairless can get an extreme form of a condition called alopecia universalis, in which eyebrows, eyelashes and body hair fail to develop. Babies are born with scalp hair, but it fails to regrow after being shaved, as is the custom in the Pakistani family in which the gene was identified.
Other work has shown that a malfunctioning hairless gene can cause another hair-loss disorder, called papular atrichia. They investigated the function of the protein that cells normally make with instructions from the hairless gene.Results suggest that it helps regulate genes that are activated by thyroid hormone. The hairless protein acts to shut those genes down when thyroid hormone is absent, researchers concluded.George, from the Johns Hopkins University School of Medicine in Baltimore, and colleagues report their study of the hairless gene in the Oct. issue of the journal Genes and Development.
According to them the hairless gene itself is activated by thyroid hormone, so it may influence its own activity as well as that of other genes targeted by the hormone. It may be a key factor in the hormone's effects in both brain and skin.