Scientists Find Possible Genetic Roots of Type of Hair Loss
Genetic Finding Could Lead to New Targets for Treatment of Alopecia Areata, Researchers Say
June 30, 2010 -- Scientists have identified eight genes that may be associated with the skin disease alopecia areata, a common cause of hair loss that affects 5.3 million Americans.
This is one of the first studies to locate genes potentially linked to alopecia areata. What is most striking about the genes identified is that they are already associated with a number of autoimmune disorders, including type 1 diabetes and rheumatoid arthritis. Now, researchers at Columbia University Medical Center in New York suggest these genes could be targets for new alopecia areata treatments.
Genes Linked to Hair Loss
One gene in particular caught the eye of study author Angela M. Christiano, PhD, a professor of dermatology and genetics and development at Columbia, and her colleagues. Known as ULBP3, this gene is normally not present in hair follicles, but ULBP3 proteins were found in high concentrations in hair follicles affected by alopecia areata. ULBP3 attracts immune cells called cytotoxic cells. If an infection is present in the body, cytotoxic cells can help fight the infection or destroy damaged cells, but if there is no infection or damage, these immune cells end up attacking healthy tissue.
The ULBP3 proteins attract cells marked by a killer cell receptor, known as NKG2D, which is also involved in other autoimmune disorders and could potentially serve as a biomarker for alopecia areata. Two other genes were also expressed in hair follicles, while the remaining five genes were involved in immune system response.
The findings are based on the genome analysis of 1,054 people with alopecia areata and 3,278 people without the disorder and appear in the July 1 issue of Nature.
“Finding the initial genes underlying alopecia areata is a big step forward, but the nature of the genes is even more exciting,” Christiano says. “There seems to be a shared mechanism among organs that express NKG2D danger signals as part of the initiating process. And since drugs are already in development that target these pathways -- because they are being tested to treat rheumatoid arthritis, type 1 diabetes, and other diseases where the NKG2D receptor is involved -- we may soon be able to test these drugs in clinical trials for alopecia areata. Finally, we have the possibility of developing drugs that specifically target the mechanism behind the disease.”