Down’s Syndrome gene may protect against cancer

 Male Down’s Syndrome with trisomy at chromosome 21

People with Down’s Syndrome are less likey to get solid tumor cancers, research from Johns Hopkins University has revealed.

Up to 95% of Down’s syndrome cases are caused by “trisomy 21″, in which the baby has three, rather than two, copies of chromosome 21, and the hundreds of genes it contains. Advances in medical management of Down’s Syndrome patients has increased life expectancy from around 30 years of age to over 60 years of age.  This increase led to some studies finding that adults with Down’s syndrome appear to have less chance of developing certain cancers which involved “solid” tumors.

On mouse studies, the Johns Hopkins team pinpointed a single gene, Ets2, and found that the chance of developing solid tumors seemed to be related to the number of copies of the gene carried by each mouse.

However, David Threadgill, an Associate Professor of Genetics at the University of Carolina at Chapel Hill, sounded a warning note. In an accompanying article, he said that there was some evidence that Ets2 could actually boost the spread, or metastasis, of cancer around the body, making it far harder to treat. There is evidence that leukemia is more prevalent in Down’s Syndrome.

He wrote: “Individuals with Down’s syndrome are at a lower risk of developing solid tumors, probably owing to the high Ets2 levels in their epithelial cells – but they might be at a greater risk of cancer metastasis.”

Elaine Warburton