Progeroid syndromes (PS) describes a range of genetic disorders where the affected person appear to grow older faster. All disorders within this group are monogenetic, meaning they come from mutations of a single gene. Most known PS are due to mutation leading to either defects in the DNA repair mechanism, or defects in a protein known as lamin A/C.
Progeroid means "resembling old age". This definition can be applied to many different diseases. Familial Alzheimer's disease and familial Parkinson's disease, an accelerated aging disease associated with aged individuals, affects only one tissue: it can be classified as an unimodal progeroid syndrome. In most cases, the term progeroid syndrome is used for segmental progeria: Wit this conditions, the affected people only show some ofthe features linked with aging, but not all of them. In these cases, many different kinds of tissue are affected. Individuals with PS-related disorders often have a reduced lifespan. The most widely studied of the progeroid syndromes are Werner syndrome (WS) and Hutchinson-Gilford progeria (HGPS), because they resemble natural aging.