military eligibility/sleep disorder

[mopinko]

does anyone know if a sleep disorder will disqualify you from military service? my 18 y.o. son is one of those people with a circadian clock that is not 24 hours. his is about 26 hours. in the course of a month, he cycles from being a day person to being a night person. there is nothing that can be done about this really. you can ameliorate it, but not really stop it. it might not sound like much, but it is impossible for him to function like a normal person.
so, would the army take a person like this? we do not have doctors diagnosis of this. long story. but if it might get him out of the draft, maybe we should do it.
thoughts?