(Image from NIH)
Wow. Researchers figured out a way to remove the extra copy of chromosome 21 that is the cause of Down's syndrome. ScienceDaily has the story here, a press release is here, and the full paper is here in Cell Stem Cell.
The removal of the extra chromosome is not a cure for Down's syndrome in living people, but it may in the future help to limit disease in persons with Down's syndrome. On the broad view, this is quite a great scientific feat, and no doubt others will build on the knowledge to develop other genomic therapies.
How was it done? "The researchers used an adeno-associated virus as a vehicle to deliver a foreign gene called TKNEO into a particular spot on chromosome 21, precisely within a gene called APP, which sits on the long arm of the chromosome. The TKNEO transgene was chosen because of its predicted response to positive and negative selection in specific laboratory growth mediums." Amazing.