Shares of companies developing CRISPR gene-editing therapies dropped in Monday morning trade after a study found that the technique can damage DNA. The research, published in the peer-reviewed journal Nature Biotechology, is just the latest questioning whether the technique brings more benefit than harms to patients, with a report in June raising the possibility that edited cells could cause cancer. Editas Medicine Inc. shares dropped 4.1%, CRISPR Therapeutics AG shares dropped 6.4 and Intellia Therapeutics Inc. shares dropped 6.3% in moderate Monday trade. Despite the sharp stock downturns, all three companies’ shares were still up year-to-date, by 18%, 162% and 58%, respectively. The S&P 500 rose 4.6% year-to-date, while the Dow Jones Industrial Average has lifted 1.2%.