An international team of researchers has identified the specific gene fault that causes a type of early-onset melanoma that accounts for about 3% of the cases of this type of skin cancer that is known to run in families.
Melanoma is a cancer in the pigment-producing cells of the skin. Sunburn and ultraviolet light exposure are risk factors for melanoma and other skin cancers, but some of the risk of developing melanoma is also genetic.
Every year in Australia, around 11,000 people are diagnosed with melanoma. The rate is even higher in New Zealand – in fact, the highest in the world – with some 2,200 people diagnosed every year. About one in 50 cases has a strong family history of the disease. Scientists have previously identified the genetic mutations responsible for about 40% of all familial cases of melanoma. This latest finding identifies the route taken by another 3% of cases, where mutations inactivate a gene called POT1, which would otherwise protect the ends of our chromosomes from damage.
Study participants came from the UK, Australia and the Netherlands – 184 people with melanoma from 105 families with a history of the disease.
Importantly, none of the study participants had the different genetic mutation that has previously been identified and associated with some 40% of the familial skin cancer cases.
Using DNA sequencing of the families involved, the team identified the common fault and found that people with mutations in the POT1 gene were at extremely high risk of developing melanoma.
“The identification of POT1 mutations in melanoma informs us of a previously unrecognised pathway that is important in regulating melanoma development,” says co-author Professor Nick Hayward from QIMR Berghofer Medical Research Institute in Australia.
“This finding significantly increases our understanding of why some families have a high incidence of melanoma. Pinpointing the genetic mutations which drive melanoma helps us to identify which people should be extra vigilant about their health and sun exposure habits.”
In the short term, the findings will help identify people at high risk who should have regular screening for melanoma. Now the gene mutations have been identified as a potential drug target, better ways of diagnosing and treating melanoma should become available in the future.
The study involved researchers from the UK, USA, the Netherlands, Spain and Australia. The findings were published in the May 2014 edition of Nature Genetics.
Find out more about melanoma.
Useful link
Get further information about melanoma in New Zealand from the Melanoma Foundation of New Zealand.
References
Robles-Espinoza, C., Adams, D. et al. (2014). POT1 loss-of-function variants predispose to familial melanoma. Nature Genetics 46, 478–481. doi:10.1038/ng.2947. Published online ahead of print, 30 March 2014 at www.nature.com/ng/journal/v46/n5/full/ng.2947.html.
