Scientists take notable step toward potential Down syndrome treatment

A therapy for Down syndrome may be just around the corner, thanks to scientists’ success in altering a genetic fault in isolated cells that ultimately leads to the condition, according to new study findings in Nature.

Through a series of experiments, US researchers extracted cells from individuals with Down syndrome and stopped activity of the extra chromosome that is responsible for the disorder.

Scientists are calling this feat a major move toward “chromosome therapy” for Down syndrome.

At the University of Massachusetts, Jeanne Lawrence led a team of scientists and used what is called genome editing, a technique that enables DNA to be manipulated, to insert a gene known as XIST (X-inactivation gene) into the extra chromosome in cells from people with the disorder.

After insertion, the gene produced a buildup of a molecule type called RNA, which covered the extra chromosome and shut it down.

Researchers’ work demonstrated that the gene can shut down other chromosomes as well, which may lead to an ability to treat other trisomy conditions, including Edward syndrome and Patau syndrome, triggered by extra copies of chromosomes 18 and 13, respectively.

The investigators detailed how cells amended for an extra chromosome 21 improved and grew efficiently into early-stage brain cells.

The research team is now working on a project to prevent mice from acquiring Down syndrome by halting the extra chromosome 21 in early-stage embryos.

In the future, chromosome therapy for humans would present ethical challenges., researchers note. To prevent Down syndrome, genome editing would have to occur on an embryo or fetus in the womb and alter most-possibly all-of the future child’s cells. 

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