Possible Genetic Link found for Hair Loss. Could a cure for baldness be near?

Researchers studying the removal of the gene Sox21 from mice made a surprise discovery – they lost their hair!

Dr. Makoto Kiso and colleagues from the National Institute of Genetics and other research centers in Japan published their findings in the study titled “The disruption of Sox21-mediated hair shaft cuticle differentiation causes cyclic alopecia in mice.” They concluded that “Sox21 is a master regulator of hair shaft cuticle differentiation and shed light on the possible causes of human hair disorders.”

When scientists want to know what a particular gene does, the easiest way to find out is to remove it and see what happens.  In this study the researchers wanted to know what role the Sox21gene plays in the development of mice.  Previous studies show the Sox21 gene has been linked to the formation of nerve cells.  Humans, like mice, carry the gene.  In this study they removed the Sox21 gene to see what would happen and had an unexpected result – the mice started losing the hair on their head around two weeks after birth and became completely bald a week later.  The mice began to re-grow hair a few days later, but then lost it again.  This cycle of hair loss and regrowth continued for at least two years in both male and female mice.

Mice going bald

To figure out why this happened they examined the hair follicles on the skin of regular mice and Sox21-lacking mice under a scanning electron microscope and a transmission electron microscope.  What they found was that the absence of the Sox21 gene “resulted in a loss of the interlocking structures required for anchoring the hair shaft into the hair follicle.  Furthermore, the expression of genes encoding the keratins and keratin binding proteins in the hair shaft cuticle are also specifically down-regulated in the Sox21-null mouse.”

The researchers conclude that the Sox21 gene has an important role in controlling the development of the hair shaft cuticle and that this finding “sheds light on the possible causes of human hair disorders.”

“It is entirely possible that the gene is also a cause of thinning hair among humans”, said Professor Yumiko Saga at the National Institute of Genetics in Tokyo in an interview with The Daily Telegraph.

In the same interview Dr. Bessam Farjo, medical director of the Institute of Trichologists, said the research added to the growing knowledge of hair loss and could help identify and target young men who will lose their hair.

“It is very interesting,” he said.  “It should help in the current research into finding a cure for hair loss. It will also help us accurately target men likely to lose their hair so we can treat them before it happens.”

While we do know that the Sox21 gene is active in the normal skin of mice and in human scalp tissue this does not necessarily mean that this gene is a cause of human baldness.  Further studies will be required to determine whether or not this is the case.  But it is possible that this research may one day lead to development of treatments to prevent or reverse hair loss.

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