Although the majority of melanomas develop due to cell damage caused by ultraviolet (UV) radiation exposure, susceptibility to melanoma is also influenced by genetics. For some families, inheritance of particular melanoma ‘risk’ genes can predispose to developing melanoma. These are grouped into ‘high’, ‘medium’ and ‘low’ penetrance genes, where penetrance reflects the likelihood of melanoma occurring over time in a person who carries the genetic mutation or polymorphism. Although no single mutation/variant guarantees disease development, the main impact is elevation of baseline melanoma risk, and it is likely that multiple low penetrance genes along with genetic and environmental modifiers combine to elicit a unique level of personal melanoma risk. In addition to cutaneous melanoma, some ‘melanoma’ predisposition genes have been linked to risk of other cancers. (By Dr. Jazlyn Read, http://jmg.bmj.com/content/early/2015/09/03/jmedgenet-2015-103150 )