In a series of experiments, described in the journal Nature, the research team from the University of Massachusetts took cells from people with Down syndrome and ‘switched off’ the extra chromosome that causes the condition. The team used ‘genome editing’, a procedure that allows DNA to effectively be be ‘cut and pasted’, to insert a gene called XIST into the extra chromosome in cells taken from people with Down syndrome. Once in place, the gene caused a buildup of a version of a molecule called RNA, which coated the extra chromosome and ultimately shut it down.
Though the research is still at a very early stage , it is conceivable that scientists could one day use chromosome therapy based on such work to minimise the symptoms of Down syndrome. As the research team write in their abstract: “Successful trisomy silencing in vitro … surmounts the major first step towards potential development of ‘chromosome therapy”.
The team’s work shows that the gene can shut down other chromosomes too, a finding that may open up new ways of treating a range of other trisomy disorders, such as Edward syndrome and Patau syndrome, caused by extra copies of chromosomes 18 and 13 respectively.
Read more about chromosomal conditions.