It only affects three in every one million children.
At birth, Charlie's white blood cell count was sky high. He had an enlarged spleen and liver, and he was covered in bruises.
Charlie's JMML is caused by a genetic mutation. The only treatment is a bone marrow transplant.
"They're looking to see if his mutation is in all of his cells or just in his leukemia cells," said his mother Jessica Cole. "I think if it's just in his leukemia cells, that's when they do a bone marrow transplant."
Charlie's older brother, 2-year-old Henry, was recently tested for the same genetic mutation, but he has no symptoms or signs of a problem. It's likely fate just hit Charlie, who is at Seattle Children's Hospital at least once a week.
"All kinds of appointments, five different teams of specialists for all his various issues. It's a lot of back and forth," said Charlie's father Jeremy Cole.
Just half of children with JMML survive, but the odds are best for little boys.
"The doctors are hopeful. His blood tests look pretty good. Usually it's really fast moving and really aggressive," Jessica said. "So far his has not been, so they think that's a good sign."
If you would like to help Charlie and his family, there are three ways to do that. First, donate blood. Charlie has already had multiple blood transfusions.
Join us on Saturday, Dec. 15 at 7 p.m. for Miracle Season, a broadcast celebrating and supporting Seattle Children's charity care program. That fund helps cover Charlie's medical expenses.
You can also follow Charlie's progress on his Facebook page.