I am desperately missing yoga, I gave it up about a year ago when my fatigue got worse, and now I have a diagnosis of HMS and have been told not to do it. Sucks.
I'd say if you are going to try it, stick with Iyengar with a teacher who knows about your condition. Unfortunately I can't afford the Iyengar classes I used to go to and don't sare do yoga at home with no one to tell me if I am hyperextending etc.
HMS (diagnosed Feb 2012, aged 38): food intolerances incl gluten, allergies, asthma, IBS, GERD, RLS, hypoglycaemia
"Feelings come and go like clouds in a windy sky. Conscious breathing is my anchor." Thich Nhat Hanh