Living life to extremes is what it's all about for eighteen year old Casey James.
"In the summer I go longboarding, ride BMX, and wakeboard a lot," James said.
In winter he's a wildman on a snowboard. But he always wears protection for his kidney with a kidney belt.
"In here it's a hard plastic piece. That just protects my kidney up front," he said.
In the front, instead of in the back, is where his mother's adult size kidney fit. It saved Casey's life when he was just three.
"You think...that you've got this great match, but it's a double edged sword," said Jo James, Casey's mother.
That's because the medications that keep Casey's body from rejecting her kidney, will eventually wear the kidney out. More than risky sports, the specter of future transplants worries his mother.
"It scares me being a mom, because the next one could be five years, and the next one could be ten years. Well he's still only 18. How many more can he have?" she asked.
"When we look at transplanting a child, we're looking at that child, in their lifetime, is going to need three perhaps four transplants," explained Dr. Ruth McDonald.
Dr. Ruth McDonald is Medical Director of Solid Organ Transplant at Seattle Children's. She's been Casey's doctor since he was two. She's thrilled Facebook is encouraging users to list their organ donor status.
"It is communicating in a way that young people are used to communicating. They're using Facebook. And I think it's really awesome," Dr. McDonald said.
Casey will count on those connections. In his bucket list for his future, which he said includes working in cinematography and art, he'll have to leave some space for a transplant along with his dreams. He said he'll go with the flow.
"I want to live my life to the fullest, live life as it comes, have fun," he said.
Dr. McDonald said the aim of research now is to develop medicines that could keep a child's body from rejecting a transplanted kidney without damaging the organ.