It's important to let instructors know that you or your child may need special accommodations and may miss classes more frequently than other students. They may be willing to provide lecture outlines or other aids if they know there's a disability that can make learning difficult.
If an instructor is unwilling to accommodate special needs, talk to a superior. You should be able to get reasonable accommodation based on disability. However, keep in mind that you may need to produce medical records to prove limitations.