Premature aging. There are 2 forms of progeria, and both are very rare. In Hutchinson-Gilford syndrome, the premature aging starts at about 4 years old, and many features of old age, including grey hair, balding, sagging skin, and atherosclerosis, have developed by age 10–12. Death usually occurs at puberty. Werner’s syndrome (adult progeria) starts in adolescence or early adulthood and follows the same progression. The cause of progeria is unknown, although it is known that the cells in affected people reproduce far less frequently than those in healthy people.