Down Syndrome: Researchers shut down extra chromosome that causes Down syndrome

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For the first time, researchers shut down the extra chromosome, chromosome 21, that causes Down syndrome.  This discovery, by researchers at the University of Massachusetts Medical School, could lead to new treatments for this condition.  "The research means that we have a new way - right away - to study the cellular basis for Down's syndrome, that could help identify drugs for Down's syndrome." said Dr Jeanne Lawrence to BBC News.

Genome editing techniques were used to insert an XIST gene into the extra chromosome that was created in the laboratory from human stem cells.  The XIST gene silenced the extra copy of chromosome 21.  (The XIST gene "creates a regulating piece of RNA that ordinarily quiets the second X chromosome in women." according to Bloomberg.com.)  When the XIST gene silenced chromosome 21, researchers observed brain cells grow more rapidly.

In practical terms, this does not mean a cure or treatment is imminent.  It does mean that research into Down syndrome took a huge step forward.  Dr Lawrence, the lead researcher for this study stated: "At the same time we have made it conceivable - not necessarily possible or effective, that still needs to be proven - but conceivable that you could use just a single gene to correct the over-expression of the whole chromosome.  So it makes genetic therapy for Down's syndrome more conceivable where it really wasn't before."

Carol Boys, chief executive of the UK's Down's Syndrome Association, told the BBC: "The findings could have serious implications for future work that may be of real benefit to people with Down's syndrome."

The study, Translating dosage compensation to trisomy 21, is published in the journal Nature.

For more information see:

http://www.boston.com/news/science/2013/07/17/laboratory-dish-researchers-shut-down-extra-chromosome-that-causes-down-syndrome/Q5P4QdOk5z67aVcPzd6dnI/story.html

http://www.bbc.co.uk/news/health-23340924

©Mary M Conneely T/A Advocacy in Action