Part of the challenge of studying baldness is that mice don't suffer from the equivalent of male-pattern baldness, making animal research less effective in understanding how hair growth works, she said.
Dr. Doris Day, a dermatologist in New York City, said that about half of people older than 50 have hair loss. "It can be debilitating, especially to women, who have fewer options for treatment," Day said.
Drugs such as Rogaine and Propecia treat baldness, but they do so by preventing future hair loss rather than growing new hair, Christiano said.
Also, Day said, the medications have side effects. "Most of the drugs block hormones or enzymes," she said. "However, they are not specific to the scalp so side effects can include decreased libido as well as potential damage to the liver."
"The medications need to be taken indefinitely in order to remain effective," she said, "and for some people, the medications do not adequately control the hair loss."
A gene-based treatment, by contrast, might allow hair to grow normally. And understanding the genetic basis of baldness could help researchers find better treatments for other conditions, such as alopecia, which causes hair loss, Christiano said, adding that she has alopecia.
The American Academy of Family Physicians has more about hair loss.
SOURCES: Angela M. Christiano, Ph.D., director, Center for Human Genetics, Columbia University Medical Center, New York City; Doris Day, M.D., dermatologist, New York City; April 15, 2010, Nature
All rights reserved