Technique inactivates Down-causing chromosome

Early-stage research could eventually lead to gene therapy

Borrowing a trick from nature, researchers have switched off the extra chromosome that causes Down syndrome in cells taken from patients with the condition.

CHROMOSOME QUIETER To shut down the extra chromosome that leads to Down syndrome, researchers inserted additional genetic material (left, in red on chromosome indicated by arrow with asterisk) into one of three copies of chromosome 21 (indicated by arrows).