Progeria: A rare genetic disorder that causes children to age prematurely. The classic type of childhood progeria is Hutchinson-Gilford syndrome, which is commonly referred to as progeria. It is characterized by dwarfism, baldness, pinched nose, small face and small jaw relative to the head size, delayed tooth formation, aged-looking skin, diminution of fat beneath the skin, stiff joints, and premature arteriosclerosis. Children with the progeria syndrome usually appear normal at birth. However, within a year, their growth rate slows and their appearance begins to change and age prematurely. They often suffer from symptoms typically seen in elderly people, especially severe cardiovascular disease. Death occurs on average at age 13, usually from heart attack or stroke.