Columbia Researchers Identify Gene For Inherited Baldness

The research, reported in the Jan. 30 issue of Science, suggests that the gene initiates a cascade of events that stimulate hair growth. Each step along this pathway may provide new clues for male pattern baldness and other forms of hair loss, or alopecia.

"The discovery of this new gene gives us endless possibilities that may allow us to effectively treat hair loss and possibly baldness within the next five years," says principal investigator Angela M. Christiano, Ph.D., Herbert Irving Assistant Professor of Dermatology at Columbia-Presbyterian. "It is now within our reach to design ways to grow hair, remove hair, even dye hair genetically and -- best yet -- this can all be accomplished topically, reducing possible side effects."

Dr. Christiano's team noticed striking similarities between hairless mice that have been used in dermatology research for nearly 50 years and a rare genetic form of balding called alopecia universalis that involves hair loss over the entire body. The researchers relied on genetic information from families affected by the disorder in a village in Pakistan. By comparing the known mouse gene with human chromosomes, the team identified the first healthy trigger gene for hair growth and the mutation that causes this type of alopecia.

The several forms of alopecia represent a disruption in the cycle of human hair growth. The most common type of hair loss, known as androgenetic alopecia, or male pattern baldness, is believed to affect some 80 percent of the population. Other forms, such as alopecia areata, a common disease affecting 2.5 million people in the United States, are thought to be related to autoimmune disfunction or stress. The molecular basis of these forms of alopecia remains a mystery.

"With the hairless gene, the real basis of hair loss can begin to be understood," says Christiano. "We can now look at the cause -- the genes themselves -- with the understanding that hormones are important but not primary."

Current treatments for hair loss focus on the regulation of the hormones involved in hair loss. Treatment for male pattern baldness traditionally has focused on hormonal regulation of the hair follicle for regrowth of hair, yet none of these approaches have provided any relief without significant side effects. But, says Christiano, "Hair follicles, like all cells, have cycles. This finding is the first indication that we may be able to regulate that cycle, triggering the growth of new hair. It may be possible, for instance, to treat hair loss through gene therapy administered topically via the hair follicles."

The market potential for products to treat alopecia is one of the largest worldwide, encompassing pharmacological agents, over-the-counter medications, personal care products, surgical procedures, hair replacement, and wigs. Collectively, consumers spend an estimated $7 billion annually on treatments and procedures to counteract hair loss in the United States alone.

Other investigators are Wasim Ahmad, Muhammad Faiyaz ul Haque, Valeria Brancolini, Hui C. Tsou, Sayed ul Haque, HaMut Lam, Vincent M. Aita, Jason Owen, Michelle deBlaquiere, Jorge Frank, Peter B. Cserhalmi-Friedman, Andrew Leask, John A. McGrath, Monica Peacocke, Mahmud Ahmad, and Jurg Ott.

The study was supported in part by the National Alopecia Areata Foundation.