Causes of death to age 30 in Down syndrome.

To look at the underlying cause of death (U.C.O.D.) data for Down syndrome (DS), we studied 324 DS individuals who died out of a total of 1,337 DS births occurring in 1,066,508 consecutive live births during the years 1952-81 inclusive. U.C.O.D. rates, separated into ICD-9 classifications, for the DS population were compared with those of the age-matched general population. In general, an individual with DS is significantly more likely to die than the age-matched general population over all ages studied up to age 30. The greatest absolute likelihood of dying is under 1 year, but the age group with the greatest relative risk of dying (17.2) is very definitely between ages 1-9. In order, the three categories for causes of death in DS with the greatest relative risk are congenital anomalies, circulatory system, and respiratory system.