In 2268, Matthew O'Hara was in command of the USS Pasteur when it was destroyed by a high-intensity ion-particle beam in the Gobi system. Survivors made it to Gobi III, the only planet in the star system capable of supporting life.
In 2269, eleven months later, the USS Enterprise located hull fragments from the Pasteur and searched for survivors. Matthew O'Hara's sister, Enterprise Lieutenant O'Hara, found a baby on Gobi III who had been created from his genetic make-up. (TOS - Year Four comic: "Issue 6")