Live mice carrying a genetic mutation for heart arrhythmias received a single injection of AAV-CRISPR or placebo. Six weeks later, none of the mice carrying the mutation treated with CRISPR developed arrhythmias. In contrast, 71% of mice with mutation who received a placebo developed arrhythmias.

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Live mice carrying a genetic mutation for heart arrhythmias received a single injection of AAV-CRISPR or placebo. Six weeks later, none of the mice carrying the mutation treated with CRISPR developed arrhythmias. In contrast, 71% of mice with mutation who received a placebo developed arrhythmias.