NEW YORK (Reuters Health) - New research suggests that a segment of chromosome 21 deemed the “Down syndrome critical region” (DSCR) actually has little effect on the structural abnormalities seen with the disorder.
In previous studies, “DSCR has been associated with short stature, the craniofacial features of Down syndrome, and also mental retardation,” senior author Dr. R. H. Reeves, Johns Hopkins University in Baltimore, told Reuters Health.
“Our study, however, shows that DSCR is not sufficient for and is largely not necessary for the craniofacial features and the short stature,” he noted. “We have studies underway to see if the region is necessary or sufficient to cause mental retardation.”
The findings, which appear in the October 22nd issue of Science, are based on a study of mice that were engineered to be trisomic or monosomic for just the DSCR, not the entire chromosome 21.
Dr. Reeves characterized the current findings as “not great news” as they suggest “the way trisomy disrupts development is a lot more complex than a one gene-one phenotype model.”
“The good news is that we now know what we have to look at,” he said. “Before, when we were trying to figure out one gene at a time, we were pretty much barking up the wrong tree.”
Source: Science 2004;306:687-690. [ Google search on this article ]
MeSH Headings:Disabled Persons: Persons: Craniofacial Abnormalities: Mentally Disabled Persons: PersonsCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
