ShutterstockHow long you live depends in part on the genes you inherit. For example, those suffering from Werner’s syndrome have inherited two defective copies of a gene coding for an enzyme that is involved in DNA replication and repair. A lack of this enzyme produces premature cell senescence – the build up of dysfunctional cells as we age which causes damage to tissue – and elevated levels of inflammatory proteins. The end result is the early development of many conditions seen in older people, such as cardiovascular disease, osteoporosis, gray hair, wrinkled skin and shrinkage of the thymus.