Mason Kiefer

Mason Kiefer is the husband of Laurie Kiefer and father of Emma and Daniel Kiefer.

History
Mason and his wife, Laurie, were expecting twins. They decided not to know the sexes of the babies. Laurie went into labor while her OB was on vacation, so Arizona Robbins stepped in to deliver the babies, but before delivery, she noticed something odd on the ultrasound. She had Alex Karev paged urgently and delivered the babies, who were both severely jaundiced. The babies were then taken to CT, where it was revealed that each of them had a large liver tumor.

The doctors informed Mason and Laurie of the situation and they decided to be tested to see if either of them was a match and could donate. Mason was a match, but Laurie was not, meaning they could only save one baby. They worried about how they would choose until Alex stepped in and said that they wouldn't have to choose; he'd be making the choice. He ran tests and compared their conditions, but the twins came out tied, so he decided that he needed to open both of them up and look directly at their tumors before he could make the choice. After the twins were opened, he evaluated each of them again and decided that Emma had a better chance, so she received the liver, while he tried resecting Daniel's tumor. Emma immediately started to improve after her surgery, but Daniel unfortunately died during his.

Romantic
He is married to Laurie Kiefer. Together, they have two children.

Familial
His twin children, Emma and Daniel, were both born with aggressive liver tumors. He matched as a donor, but was only able to donate to one, so Emma got a portion of his liver while Daniel died.