Hi, Janet!
What an accomplishment for your son? Congratulations to you both.
Your best bet, I think, will be to make contact with someone at
runDisney in advance of race day. This way, you'll be able to provide all relevant information and details about your runner and his needs, and someone from Endurance will have sufficient time to make arrangements for you all.
Start by filling out their
online contact form. They are very good about responding in a reasonable amount of time.
The telephone number at the ESPN Wide World of Sports Complex is 407 938 3398.
Should those two approaches not prove successful, you might try to contact one of the personnel affiliated with the races. One local store - Track Shack - is extremely involved with runDisney; its owner, in fact, has been the Director of the Marathon since its inaugural year (1994). Contact them through their Events number: 407 896 1160.
Let me know if I ca be of any further help to you and your runner.
See you later, celebrator!
-Deborah B.