Sydney, July 13 - Scientists have discovered two new genes that double a person's chances of developing melanoma -- the deadliest form of skin cancer.

As part of an international study, a team at the Queensland Institute of Medical Research (QIMR), led by Nick Hayward and Grant Montgomery, studied the genes of almost 6,000 people together with their mole count.

Specific changes in two genes were found to make people more susceptible to developing moles. The researchers went on to show, in another 4,000 people, the same two genes increased the risk of developing melanoma.

'These are the first genes found to increase melanoma risk by influencing the number of moles a person has,' explained Hayward.