Scientists from the University of Southern California have teamed up with researchers from Beijing, China and have together discovered a chromosomal mutation that may give hope for a new baldness treatment in the future. This mutation causes a rare condition in which individuals grow an excessive amount of hair all over their body. The hope is it will lead to a treatment for this condition, other forms of excessive hair growth and, one day, hair loss.
The study was published in the American Journal of Human Genetics in 2011. The first discovery of the chromosomal mutation occurred in the lab of Zue Zhang, a professor at Peking Union Medical College. Zhang was studying the condition, called CGH, in a family from China. Researchers at Zhang’s lab worked with Sunji Choi, an associate of Pragna Patel at USC, who also confirmed the mutation finding in a Mexican family that Patel first studied in 1993. Males with the CGH disorder have hair on every bit of their face, including the eyelids, as well as the upper body. Women with the disorder have thick patches of excessive hair growth all over the body.
According to Patel, the approximate location of the CGH mutation was traced to the X chromosome in 1995 after studying the Mexican family. After sequencing over 100 genes, they still couldn’t find the mutation. Xue Zhang and colleagues in China were finally able to isolate the location of the CGH mutation after finding there is an insertion of chromosome 5 into the X chromosome while studying the family in China. Once this discovery was made, Patel’s team re-examined the Mexican family and found there was indeed a portion of chromosome 4 inserted into the same location of the X chromosome, confirming the findings.
It seems the insertion of this additional DNA sequence into the X chromosome triggers a gene near the insertion site. Researchers believe the gene activated is the SOX3, as others in the gene family have been linked to hair growth. The insertion also happens within a palindrome block of sequence, although researchers still don’t know the significance of that in this particular case. It seems unstable, as it can be absent in people with typical hair growth. The insertion of extra segments of chromosomes do trigger the excessive hair growth, however.
Researchers have previously hypothesized that the mutation is atavistic, which is a type of trait that remains absent for long periods of time and suddenly reappears when it’s activated.
So how does this apply to hair loss? If researchers can insert DNA sequences to turn on a gene that triggers the hair growth, it may be used in the future to treat baldness, as well as excessive hair growth conditions. Scientists may be able to engineer a means of achieving this through drugs or therapy, although any treatment is still many years away.