You can blame it on the gene! Researchers discover new gene for hair loss

November 06, 2018

Picture of a hair growing inside the scalp (c) Uni Bonn

 

In infancy, fine hair tends to sprout sparsely. With increasing age, hair loss progresses. Ultimately, only a few hairs are left on the head and body. Hypotrichosis simplex is a rare form of hair loss (alopecia). The condition is limited to a few hundred families worldwide. So far, only a few genes are known that are causally related to the disease. Under the leadership of the Institute of Human Genetics at the University Hospital of Bonn, a team of researchers from Germany and Switzerland has now deciphered mutations in another gene that are responsible for hair loss.

 

The scientists 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. All those affected had mutations in the LSS gene. “This gene encodes lanosterol synthase - LSS for short,” said Prof. Dr. Regina C. Betz from the Institute of Human Genetics at the University Hospital of Bonn. “The enzyme plays a key role in cholesterol metabolism.” However, the cholesterol blood values of those affected are not changed. Betz: “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."

 

Mutation leads to displacement of lanosterol synthase

 

Using tissue samples, the scientists tried to find out exactly where the lanosterol synthase 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. “We are not yet able to say why the hair is falling out,” says lead author Maria-Teresa Romano, a doctoral student in Prof. Betz's team. “It is likely that the displacement of LSS from the endoplasmic reticulum results in a malfunction.”

 

Prof. Dr. Matthias Geyer from the Department of Structural Immunology at the University of Bonn investigated the consequences of mutations for the structure of the enzyme lanosterol synthase. With him and Prof. Betz, there are now two principal investigators from the Cluster of Excellence ImmunoSensation of the University of Bonn, which was impressively endorsed in the latest round of the Excellence Competition and will receive further funding.

The full article is available online DOI: https://doi.org/10.1016/j.ajhg.2018.09.011 the full press release can be read by clicking on the respective languages, German and English.