X0306 4 2021-03-30 0 0001807120 Design Therapeutics, Inc. DSGN 0001848319 SR One Capital Fund I Aggregator LP 985 OLD EAGLE SCHOOL ROAD, SUITE 511 WAYNE PA 19087 0 0 1 0 0001853724 SR ONE CAPITAL PARTNERS I, LP 985 OLD EAGLE SCHOOL ROAD, SUITE 511 WAYNE PA 19087 0 0 1 0 0001853723 SR ONE CAPITAL MANAGEMENT, LLC 985 OLD EAGLE SCHOOL ROAD, SUITE 511 WAYNE PA 19087 0 0 1 0 Common Stock 2021-03-30 4 C 0 4439839 A 4439839 D Common Stock 2021-03-30 4 C 0 936637 A 5376476 D Common Stock 2021-03-30 4 P 0 250000 20.00 A 5626476 D Series A Preferred Stock 2021-03-30 4 C 0 7236938 0.00 D Common Stock 4439839 0 D Series B Preferred Stock 2021-03-30 4 C 0 1526718 0.00 D Common Stock 936637 0 D The Series A Preferred Stock and the Series B Preferred Stock were converted into Common Stock on a 1.63-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A Preferred Stock and Series B Preferred Stock were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date. The reported securities are held directly by SR One Capital Fund I Aggregator, LP. SR One Capital Partners I, LP is the general partner of SR One Capital Fund I Aggregator, LP, and SR One Capital Management, LLC is the general partner of SR One Capital Partners I, LP. Simeon George, M.D. is the managing member of SR One Capital Management, LLC. Each of SR One Capital Partners I, LP, SR One Capital Management, LLC and Mr. George may each be deemed to have shared power to vote or dispose of these shares, and each disclaims beneficial ownership of the shares except to the extent of any pecuniary interest therein. SR One Capital Fund I Aggregator, LP purchased 250,000 shares of Common Stock of Design Therapeutics, Inc. (the "Issuer") in connection with the Issuer's public offering. SR ONE CAPITAL FUND I AGGREGATOR, LP, By: SR ONE CAPITAL PARTNERS I, LP, its General Partner, By: SR ONE CAPITAL MANAGEMENT, LLC, its General Partner, By: /s/ Simeon George, Member 2021-03-31 SR ONE CAPITAL PARTNERS I, LP, By: SR ONE CPAITAL MANAGEMENT, LLC, By: /s/ Simeon George, Member 2021-03-31 SR ONE CAPITAL MANAGEMENT, LLC, By: /s/ Simeon George, Member 2021-03-31