Researchers find curly hair gene

Researchers at the Queensland Institute of Medical Research (QIMR) have found a gene that that influences whether people from European backgrounds have curly or straight hair.

Professor Nick Martin and Dr Sarah Medland of the QIMR Genetic Epidemiology Laboratory have found that different forms of the trichohyalin gene in people with European ancestors influence the straightness or curliness of hair.

Dr Medland said, “The trichohyalin gene is involved in the sheath surrounding the hair follicle; we have known this for years. Our research is new because we have identified a link between this gene and the degree of curliness of the hair itself.”

“Our studies found that in people with European ancestry, variations in this gene influence if you are likely to have straight, wavy or curly hair.”

Previous research by Dr Fujimoto from the University of Tokyo has identified the genes responsible for thick, straight hair in Asian populations, but there is little work done on European hair.

“This is where our research came in. We focussed on Australian twins of European ancestry, to determine which genes influence straight hair in these populations.”

Around 45% of Europeans have straight hair, 40% have wavy hair and 15% have curly hair.

“Worldwide, the most common form of this gene leads to curly hair, but over time, European populations developed a change in the gene that caused straight hair,” said Dr Medland.

Researchers at the QIMR laboratory analysed data collected from a study of 5,000 Australian twins of European descent over a 30 year period. This group is used to research a range of diseases, to determine genetic and environmental components that contribute to serious illnesses.

Professor Nick Martin says this finding might help enable investigators to create a physical description of suspects directly from DNA.

“The most immediate application is likely to be in forensics. We might be able to refine identikit pictures from DNA samples left at a crime scene to say whether the suspect is likely to have straight or curly hair,” said Prof Martin.

“We can already predict their hair and eye and skin colour, so this would be another trait to refine the picture.”

The discovery may also lead to new ways to manipulate hair by using proteins. “Potentially, further research may produce ways to make hair curlier or straighter with proteins, rather than treating the hair directly,” said Prof Martin. “However, no plans are in the pipeline at this point.”

Both Prof Martin and Dr Medland have a special interest in curly hair: they both possess the trait themselves. “I love my hair, just the way it is,” said Dr Medland.

The paper is published in the December edition of the American Journal of Human Genetics.