Power of Attorney for Section 16 Reporting Obligations

Brian Posner, a director of Dyne Therapeutics, Inc., has granted a limited power of attorney to John Cox, Erick Lucera, Dan Wilson, and Ron Caponigro. This power of attorney authorizes them to execute and file Forms 3, 4, and 5 on behalf of Posner in accordance with Section 16(a) of the Securities Exchange Act of 1934. The attorneys-in-fact are also authorized to perform any necessary actions related to these filings, including obtaining transaction information from third parties. The power of attorney remains in effect until Posner is no longer required to file these forms, unless revoked earlier in writing.