Down syndrome is a genetic condition with mental and physical disabilities caused by an extra copy of chromosome 21.
People with Down syndrome, who live to an average age of 56 today vs. 25 in 1983, have lower-than-expected rates of common cancers. While Down syndrome children are more likely to get acute myeloid leukemia, a rare form of the disease, they respond better to treatment and have fewer relapses.
"Individuals with Down syndrome, who are too often viewed as a burden on society, have in fact provided us with a major clue that is fundamental to the health of everyone," John Hopkins University researcher Roger Reeves told the Wall Street Journal.
Much of the research at numerous U.S. institutions focused on the additional protein endostatin produced by chromosome 21.
In Boston studies of mice, Beth Israel Deaconess Medical Center researchers say endostatin appears to hinder development of blood vessels that feed tumors.