The disease, or sometimes the symptom is called Necrosis. The cells in his hand died and it had to be "amputated" or cut off. I'm sorry about his hand. Whoever came up with the 3D prosthetic printer is a miracle worker. I'm glad he can run around and play again. And it has helped a lot of people just like your cousin.

Dude.. That is awesome. I'm gonna download that :D

this is going to help a lot of people cause i have little cousin who had his hand dieing of a sickness and had to be taken off and he got this hand and BOOM he can play again

This makes me feel that there is still hope for me.