X0202 SCHEDULE 13G/A 0001527166 XXXXXXXX LIVE 1 Common Stock, par value $0.0001 per share 06/30/2026 0001661998 Q32 Bio Inc. 746964105 830 Winter Street Waltham MA 02451 Rule 13d-1(c) The Carlyle Group Inc. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 CO Carlyle Holdings I GP Inc. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 CO Carlyle Holdings I GP Sub L.L.C. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 OO Limited Liability Company Carlyle Holdings I L.P. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 PN CG Subsidiary Holdings L.L.C. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 OO Limited Liability Company TC Group, L.L.C. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 OO Limited Liability Company Carlyle Investment Management L.L.C. DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 OO Limited Liability Company Carlyle Genesis UK LLC DE 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 OO Limited Liability Company Abingworth LLP X0 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 PN Abingworth Bioventures VII LP X0 0.00 691735.00 0.00 691735.00 691735.00 N 4.1 PN Q32 Bio Inc. 830 Winter Street, Waltham, MA, 02451 Each of the following is hereinafter individually referred to as a "Reporting Person" and collectively as the "Reporting Persons." This statement is filed on behalf of: The Carlyle Group Inc. Carlyle Holdings I GP Inc. Carlyle Holdings I GP Sub L.L.C. Carlyle Holdings I L.P. CG Subsidiary Holdings L.L.C. TC Group, L.L.C. Carlyle Investment Management L.L.C. Carlyle Genesis UK LLC Abingworth LLP Abingworth Bioventures VII LP The principal business address of each of Abingworth LLP and Abingworth Bioventures VII LP is 38 Jermyn Street, London, SW1Y 6DN, England, United Kingdom. The principal business address of each of the other Reporting Persons is c/o The Carlyle Group, 1001 Pennsylvania Ave. NW, Suite 220 South, Washington, DC 20004-2505. Each of Abingworth LLP and Abingworth Bioventures VII LP is organized under the laws of England and Wales. Each of the other Reporting Persons is organized under the laws of the State of Delaware. Y The information contained on the cover pages to this Schedule 13G is incorporated by reference into this Item 4. The ownership information presented below represents beneficial ownership of Common Stock of the Issuer as of June 18, 2026, based upon 16,956,415 shares of Common Stock outstanding, as disclosed in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 5, 2026. Abingworth Bioventures VII LP is the record holder of the shares of Common Stock reported herein. The Carlyle Group Inc., which is a publicly traded entity listed on Nasdaq, is the sole shareholder of Carlyle Holdings I GP Inc., which is the sole member of Carlyle Holdings I GP Sub L.L.C., which is the general partner of Carlyle Holdings I L.P., which, with respect to the securities reported herein, is the managing member of CG Subsidiary Holdings L.L.C., which is the managing member of TC Group, L.L.C., which is the managing member of Carlyle Investment Management L.L.C., which is the sole member of Carlyle Genesis UK LLC, which is the principal member of Abingworth LLP. Abingworth Bioventures VII LP has delegated to Abingworth LLP all investment and dispositive power over the securities held of record by them. Accordingly, each of the foregoing entities may be deemed to share beneficial ownership of the securities held of record by Abingworth Bioventures VII LP, but each disclaims beneficial ownership of such securities. 4.1% 0 691,735 0 691,735 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Exhibit 99: Joint Filing Agreement (previously filed) The Carlyle Group Inc. /s/ Anne K. Frederick 07/06/2026 Carlyle Holdings I GP Inc. /s/ Anne K. Frederick 07/06/2026 Carlyle Holdings I GP Sub L.L.C. By: Carlyle Holdings I GP Inc., its sole member, /s/ Anne K. Frederick 07/06/2026 Carlyle Holdings I L.P. /s/ Anne K. Frederick 07/06/2026 CG Subsidiary Holdings L.L.C. /s/ Anne K. Frederick 07/06/2026 TC Group, L.L.C. /s/ Anne K. Frederick 07/06/2026 Carlyle Investment Management L.L.C. /s/ Anne K. Frederick 07/06/2026 Carlyle Genesis UK LLC By: Carlyle Investment Management L.L.C., its sole member, /s/ Anne K. Frederick 07/06/2026 Abingworth LLP /s/ Emma O'Reilly 07/06/2026 Abingworth Bioventures VII LP /s/ Emma O'Reilly 07/06/2026