GeneDx Holdings Corp

Other Information

None.

Rule 10b5-1 Plan Adoptions and Modifications

On November 7, 2024, a grantor annuity trust (the “GRAT”) of which Jason Ryan, ourchairman and a director, is the trustee, entered into a written plan for the potential transfer of up to an aggregate of 141,356 shares of our Class A common stock (the “Ryan GRAT 10b5-1 Plan”). The Ryan GRAT 10b5-1 Plan is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act and will be effective from November 19, 2025 to March 5, 2027.

The Ryan GRAT 10b5-1 plan included a representation from the GRAT to the broker administering the plan that the GRAT was not in possession of any material nonpublic information regarding the Company or the securities subject to the plan. A similar representation was made to us in a certification from Mr. Ryan provided to us in connection with the adoption of the applicable plan under our insider trading policy. Those representations were made as of the date of adoption of the Ryan GRAT 10b5-1 Plan or the certification, as applicable, and speak only as of those dates. In making those representations, there is no assurance with respect to any material non-public information of which the GRAT or Mr. Ryan was unaware, or with respect to any material non-public information acquired by the GRAT, Mr. Ryan or us after the applicable date of the representation.

Other than as disclosed above, during the quarter ended December 31, 2024, none of our directors or officers adopted orterminated any “Rule 10b5-1 trading arrangements” or any “non-Rule 10b5-1 trading arrangements,” as each term is defined in Item 408 of Regulation S-K.