Researchers have deciphered a new gene responsible for a rare form of genetic hair loss condition.
Hypotrichosis simplex occurs without other abnormalities. In infancy, fine hair tends to sprout sparsely. With increasing age, hair loss progresses. Ultimately, only a few hair is left on the head and body.
A team of researchers from the University Hospital of Bonn found that changes in the lanosterol synthase (LSS) gene lead to impairment of an important enzyme that has a crucial function in cholesterol metabolism.
However, the cholesterol blood values of those affected are not changed, the finsings showed.
"There is an alternative metabolic pathway for cholesterol, which plays an important role in the hair follicle and is not related to blood cholesterol levels," said Regina C. Betz from the University's Institute of Human Genetics.
For the study, reported in the American Journal of Human Genetics, the team examined the coding genes of three families that are not related to each other and are of different ancestry.
A total of eight relatives showed the typical symptoms of hair loss and had mutations in the LSS gene.
Using tissue samples, the scientists tried to find out exactly where the LSS is located in the hair follicle cells. The hair roots are formed in the follicle.
If the LSS gene is not mutated, the associated enzyme is located in a system of very fine channels in the follicle cells, the endoplasmic reticulum.
If a mutation is present, the lanosterol synthase also spreads outside these channels into the adjacent substance, the cytosol, the scientists observed.
"We are not yet able to say why the hair is falling out," said lead author Maria-Teresa Romano, a doctoral student from the varsity.
"It is likely that the displacement of LSS from the endoplasmic reticulum results in a malfunction."
"A better understanding of the causes of the disease may in future enable new approaches to the treatment of hair loss," Romano said, adding that there is still a long way to go.
However, the discovery of the gene already contributes to an improved diagnosis of the rare disease.