Scientists from China and the USA have identified a genetic region linked to 'werewolf syndrome', a condition that causes excessive hair growth. The condition also known as hyper-trichosis is very rare - fewer than 100 cases have ever been recorded worldwide. Women with the condition tend to have thick patches of hair all over their body, while men typically have thick hair that covers their entire face; including eyelids, and their upper body.
Although hyper-trichosis is rare, it tends to run in families, suggesting the condition may have an underlying genetic component, which is passed on from one generation to the next.
Researchers from the University of Southern California, USA, working with scientists from Beijing, China, studied the genome of a Chinese man with hyper-trichosis, and identified a defective region of the X chromosome they believe is linked to the condition. They discovered the man had an extra stretch of DNA known as an 'inserted sequence' in a region very close to SOX3, a gene known to be involved in hair growth. The inserted sequence had altered the activity of SOX3, leading to excessive hair growth.
The finding was also confirmed in a Mexican family, in which several members had hyper-trichosis. But in this case, although the location of the insertion was the same, the 'inserted sequence' itself was not the same as in the Chinese man. This suggests it is the region of the X chromosome that is more important in controlling hair growth, rather than the exact defect itself.
This study may lead to improvements in the treatment of hyper-trichosis, but the researchers also hope the discovery could lead to treatments for male pattern baldness. Professor Pragna Patel, from the University of Southern California and who was involved in the study, told the Daily Mail: 'If in fact the inserted sequences turn on a gene that can trigger hair growth, it may hold promise for treating baldness'.
The study was published in the American Journal of Human Genetics.