The proportion of variation in a population trait that can be attributed to inherited genetic factors. Heritability estimates range from 0 to 1 and are often expressed as a percentage. A number close to 1 may be indicative of a highly heritable trait within a population. It should not be used to estimate risk on an individual basis. or In medicine, describes a characteristic or trait that can be passed from a parent to a child through the genes. Several types of cancer have heritable forms, in which the risk of developing a particular type of cancer is inherited from a parent. Some signs of heritable cancer are a family history of the cancer, mutations (changes) in certain genes passed from a parent to a child, or a mutation that occurs at the time of conception (fertilization of an egg by a sperm). Heritable forms of cancer often develop at an early age.