To identify a gene involved in controlling hair texture, Dr. Christiano and her team performed a genetic analysis of six families of Pakistani origin, who all shared hereditary woolly hair. The cause of hereditary woolly hair was found to be a mutation in a gene called P2RY5. Until this discovery, the pathogenesis of hereditary woolly hair had been largely unknown.
As the authors write in the paper, "The bulb region of plucked hairs from woolly hair patients showed irregular bending without attachment of the root sheath." They propose that mutations in P2RY5 most likely result in hair follicle disruptions, which then compromise its anchoring to the hair shaft and cause the abnormal bending of the bulb region, leading to woolly hair.
Dr. Christiano's discoveries have led to the identification of several genes controlling human hair growth. It remains to be determined whether common variants on the P2RY5 gene can also contribute to naturally occurring variations in hair texture between different human populations.
According to the researchers, P2RY5 is the first gene of a type known as a G-protein coupled receptor (GPCR) implicated in a human hair disorder thereby making it possible to develop drugs that target this receptor. GPCRs represent the largest known class of molecular targets with proven therapeutic value. It is estimated that more than 40 percent of existing drugs work by targeting GPCR drug targets; this target class represents a large fraction of the total biological targets against which FDA-approved oral drugs are directed. Of the top 200 best-selling prescription drugs more than 20 percent interact with GPCRs, providing worldwide sales of over $20 billion.
|Contact: Elizabeth Streich|
Columbia University Medical Center