Here's what we know about Freak's condition:
* He's in a wheelchair: This suggests a physical disability that affects his mobility.
* He's described as being "small" and "weak": This indicates that his condition has affected his physical development.
* He's intelligent: He's described as a brilliant mind with a love for knowledge. This contrasts with the physical limitations of his disease.
* He has a heart condition: The book mentions he needs a heart transplant, suggesting his condition has a significant impact on his health.
The lack of a specific name for Freak's disease is intentional. Philbrick wants readers to focus on the characters' internal struggles and the power of friendship, rather than focusing on the medical details of a specific disability.