Scientists may have tapped into a potential Fountain of Youth after discovering that gene therapy can restore hair color and can temporarily get rid of the gray.

While such treatment may be years away, Dr George Cotsarelis and colleagues in Philadelphia have found that repairing genes in the follicles of albino mice effectively produced colored hair.

Gray hair is caused by the loss of color-producing cells called melanocytes, which occurs naturally during aging. Scientists at Thomas Jefferson University and Jefferson Medical College and at the University of Pennsylvania, in Philadelphia, either injected a gene into the skin of fifteen mice or used a topical gene treatment.

Within a few weeks, a small number of colored hairs grew at the treatment site. But the color only lasted about three months. Researchers say determining how to correctly repeat the gene mutation responsible for producing hair pigment could provide more lasting color effects.

"Gene therapy has just taken a cosmetic step forward," Robert M. Hoffman, president of the San Diego, California based company AntiCancer Inc., wrote in an editorial accompanying the study. Both articles appear in the January issue of Nature Biotechnology.

Albino mice have white hair but this is not the same as having hair go white due to age. Albino mice, like albino humans, have a genetic defect that stops the production of melanin pigment. It is important to note that albinism in all these mice is due to a specific defect in the tyrosinase gene (Tyr) resulting from a homozygous c/c allele presence. These defective alleles result in an inability to convert a molecular substrate to the ultimate melanin pigment product. The inability of albino mice to produce pigment stems not from an absence of melanocytes and/or melanocyte activity, but from a deficiency or alteration of the tyrosinase structure in melanocytes that are otherwise normal. What the researchers did was to replace the defective tyrosinase c alleles with normal C alleles making the gene functional again.

Albino mice do have melanocytes in their hair follicles but they are amelanotic, whereas hairs that are white due to age have a reduced number of, or no, melanocytes present in the hair follicles. So this gene therapy by Dr. George Cotsarelis and company is not so much a treatment for white hair, but is a demonstration that defective genes in hair follicles can be replaced using gene therapy.