Leonardo's genetics get the coding for one very important protein wrong. As a result, the myelin sheath insulating his neurons is incorrectly formed. It doesn't work quite right. His condition is called Pelizaeus-Merzbacher Disease. Confirmed by a genetic test, PMD is one of the diseases "floppy babies" are found to have. These babies lack muscle tone.

In 2008, Leonardo's parents came to China to evaluate hospitals delivering adult stem cell therapies. They wanted to know if the treatments were real and whether there was a chance their son could benefit from them. In 2010 they returned for his third treatment cycle. Click here to jump to Leonardo's patient experience and video. In the video his father discusses their decision to come to China and the improvements he has seen in his son's condition since treatment began.