News Beth Israel Scientists Silence Extra Chromosome 21 in Down Syndrome Cells Using CRISPR-Based XIST Gene Insertion by Dr Natalie Singh - Health Editor April 20, 2026 by Dr Natalie Singh - Health Editor April 20, 2026 In a Boston laboratory last month, scientists used a modified CRISPR tool to insert the XIST gene into 20‑40 percent of Down syndrome cell lines, effectively silencing the extra chromosome … 0 FacebookTwitterPinterestEmail