Most cases of melanoma are caused by sun exposure. But, a small proportion of these are people who have a genetic predisposition to the disease. Researchers at the Sanger institute have discovered mutations in a specific gene that are responsible for this hereditary form of melanoma.

Of the 12,000 people a year that are diagnosed with melanoma in the UK, 1 in 20 have a strong family history. The discovery of the gene responsible now paves the way for a screening and early detection system.

The team found that people with specific mutations that deactivate the POT1 gene were extremely likely to develop melanoma. The POT1 gene protects the ends of our chromosomes from damage. Inactivation of POT1 caused by these mutations leads to longer and potentially unprotected telomeres, a part of the chromosome that protects our DNA from damage.

Dr Safia Danovi, of Cancer Research UK said:

“This is a step forward for people with a strong family history of melanoma, the most dangerous form of skin cancer. But it’s important to remember that, for most of us, avoiding sunburn and sunbeds is the best way to reduce the risk of this disease.”

The implications are huge, beyond early screening systems. Now that the genetic basis has been identified this opens doors for targeted medications and gene therapy. Until know we have only managed to identify 40% of the genetic mutations that cause hereditary melanoma.

The POT1 mutation is also linked to other cancers such as leukaemias and brain tumours. The team are now developing cells and mice with an inactive POT1 in order to test targeted drugs that aid telomere metabolism.