March 21, 2002 -- People with Down syndrome are living twice as long as they did just 20 years ago. A new study shows life expectancy for Down patients has gone from 25 years in 1983 to 49 years in 1997.
Down syndrome is one of the most common causes of mental retardation and occurs in about one of every 800 births. Although initial survival during the first year of life has improved dramatically over the last 50 years, little is known about the long-term survival or causes of death among Down patients.
Researchers at the CDC found the average age at death increased from 25 to 49 years in less than two decades. But the average age of death was much lower among blacks and other nonwhite races.
The study is published in the March 23 issue of The Lancet.
However, researchers say they were surprised to find that Down syndrome seemed to reduce the risk of many forms of cancer. Deaths caused by cancers other than leukemia and testicular cancers were found only one-tenth as often as would have been expected in other people.
Researchers say several factors may explain the improvement in survival rates for Down syndrome patients. They include:
- De-institutionalizing affected infants and placing them with their families
- Better treatment for known causes of death
- Changes in medical practices, such as providing heart surgery for children with Down syndrome to correct heart defects
- An increase in pregnancy termination after a prenatal diagnosis of more severe cases of Down syndrome