A healthy individual loses about 100 strands of hair daily, with losses occurring evenly around the whole scalp. However, this hair is replaced. The problem begins when the shedding goes beyond that number, and replacement lags. Now, after six years of study, researchers at the University of Bonn have identified a gene that causes a rare hereditary form of hair loss - Hypotrichosis simplex - throwing open the possibility of regenerating hair.
These researchers are the first to identify a receptor that plays a role in hair growth. They now hope that their research findings will lead to new therapies that will work with various forms of hair loss.
"Although Hypotrichosis simplex is very uncommon, it may prove critical in our search for an understand of the mechanisms of hair growth," Nature quoted project leader Dr. Regina Betz from Bonn's Institute of Human Genetics, as saying.
At fault is a genetic defect that prevents certain receptors on the surface of hair follicle cells from being correctly formed.
For the hair follicle to function normally, messengers must bind to these receptors, triggering a chain reaction in the cell interior.
The fact that a receptor plays a specific role in hair growth was previously unknown.
Professor Dr. Markus Nothen, who holds the Chair of Genetic Medicine at Bonn University's Life and Brain Centre, said: "The defective receptor structure falls into the category of what are known as G-protein-coupled receptors."
This is good news, Dr Nothen says, because, "they are particularly well suited as points of impact for drug treatments."
The researchers have also been able to find an endogenous messenger that binds in the hair follicle to the receptor, which opens up opportunities for developing new active agents.
As part of the study, another member of the project team, dermatologist Khalid Al Aboud of the King Faisal Hospital in Makkah examined a Saudi Arabian family with Hypotrichosis simplex.
DNA samples from the parents and from nine of their 10 children - including four sufferers - were analysed, providing the researchers the key to understanding some of the fundamental mechanisms of hair growth and loss.
The researchers now hope that this individual genetic case will lead to developments that can benefit more patients.
The study is due to appear in the March edition of Nature Genetics.