Mr. Johnson is the father of Bryce Johnson.
After his baby was born at Seattle Grace Hospital, the peds doctors detected a heart murmur which they believed was benign, but when Meredith thought differently, she told the baby's parents. As a result, Dr. Kay allowed Burke to take the baby on as his patient and get an echo.
After the echo, it was revealed that the baby had a birth defect and needed heart surgery. Burke then booked the OR for the following day.
He is married to Ms. Johnson and they have one child.