You might want to ask the MD/PhD folks. It might help you in some places and hurt you in others. It is a bit risky to highlight something that might cast doubt on your ability to finish a rigorous 7-8 year program. You may be able to make the same point without mentioning the disease for example you could say you spent several years in and out of hospitals which exposed you to the medical field etc. There's no reason they need to know your complete medical history.
