Progeria () (Hutchinson–Gilford progeria syndrome, HGPS, progeria syndrome) is an extremely rare genetic disorder wherein symptoms resembling aspects of aging are manifested at a very early age. Progeria is one of several progeroid syndromes. The word progeria comes from the Greek words "pro" (), meaning "before" or "premature", and "geras" (), meaning "old age". The disorder has a very low incidence rate, occurring in an estimated 1 per 8 million live births. Those born with progeria typically live to their mid teens to early twenties. It is a genetic condition that occurs as a new mutation, and is rarely inherited, as carriers usually do not live to reproduce. Although the term progeria applies strictly speaking to all diseases characterized by premature aging symptoms, and is often used as such, it is often applied specifically in reference to Hutchinson–Gilford progeria syndrome (HGPS).