Comparative survival advantage of males with Down syndrome.

In virtually all countries life expectancy is longer in females than in males. A multigeneration, population-based dataset was used to investigate whether a gender-specific difference in life expectancy could be determined in a large cohort (n = 1,332) of people with Down syndrome resident in Western Australia. Contrary to the established pattern of longevity in the general population, and in most people with intellectual disability, males with Down syndrome had a significantly greater life expectancy than females with the same disorder. The reasons for this atypical finding are discussed in terms of the patterns of morbidity experienced by people with Down syndrome, especially at early and late stages of their lifespan.