Legend has it their tempers are on par with their hair - fiery. But University of Queensland researchers have found there may also be a real genetic link between red heads and melanoma.
The Government Employees Medical Research Fund has granted Dr Rick Sturm of the Centre for Molecular and Cellular Biology $45,000 to continue his research into the study of the relationship between skin color and cancer.
White Australians, and Queenslanders in particular, have the highest incidence of skin cancer in the world and it has long been believed that lighter skin colour is more susceptible to the damaging effects of ultra-violet rays in sunlight.
But Dr Sturm said while there was a direct correlation between sun exposure and the formation of basal and squamous cell carcinoma skin lesions for those with fair skin, the relationship between sun exposure and melanoma formation was less clear.
'Some individuals, and in particular those with red hair, may lack the ability to mount the protective tanning response after going out in the sun,' Dr Sturm said.
'This means instead of increasing their level of protection by developing a tan, the melanocyte cell, which produces the colour of the skin, may be damaged, and more than just by UV-rays alone.
'By trying to gain a tan, the combination of genotype and sunlight could result in mutagenic products forming in the melanocyte and contributing to the formation of a melanoma.'
According to the research, the red hair gene encodes the melanocyte stimulating hormone receptor (MSHR) which dictates the skin's tanning response. The gene is the human equivalent of the gene which produces the colouration in red foxes, chestnut horses and red Holstein cattle.
Dr Sturm said the research into genes determining the characteristics of skin and hair color, was in collaboration with Professor Nick Martin and Dr Louise O'Gorman of the Epidemiology Unit at the Queensland Institute of Medical Research (QIMR). It would provide a genetic understanding of skin colour and skin tanning response after sun exposure.
Early findings in the group's research have already been published in journals overseas, including the prestigious American Journal of Human Genetics and Human Molecular Genetics .
Dr Sturm said at least one genetic link between red hair and melanoma had been found during research this year at the University. One form of the gene was present in 20 percent of a group of melanoma patients.
'One of the difficulties facing doctors is that it is very hard to define skin types,' Dr Sturm said.
'Six general classes range from people who just do not tan but burn in the sun to the other end of the scale, which includes those who generally do not have to worry about sun exposure.
'Those in the second and third groups, who sometimes tan and sometimes burn, are the problem. And although in general the advice is to stay out of the sun, we live in the real world.
'Melanomas have a 95 percent cure rate but if left unchecked they quickly become fatal. Prevention is better than cure and ideally I would like to see people being genotyped for the MSH receptor so they are aware of their genetic background and their risk of melanoma.'
PhD student Neil Box has characterised variations in the human MSH receptor gene, using sets of south-east Queensland-based twins gathered by Professor Martin for a study of mole formation and its relationship to melanoma.
Mr Box said extensive gene variation within the population had been a surprise.
'We have found more than a dozen different types of the MSH receptor gene - some in people with red hair, some in other colours. This is the beginning of a whole new definition of skin type,' he said.
'If we look at the different forms of the MSH receptor gene in melanoma patients we may be able to find an association with genotype and melanoma risk.'
Dr Sturm said he applauded the funding by the Government Employees Medical Research Fund, a charitable fund established through voluntary contributions made by Federal government employees to support health research in Australia.
'It is now much harder to get financial support from government bodies like the National Health and Medical Research Council so for work like this to continue other avenues must be sought to continue our studies,' he said.
For information contact Dr Rick Sturm (telephone (07) 3365 1831).
