Does a disorder change an individual's ability to contribute to society?

Do severe physical or mental and physical disorders (severe based on their ability to lower IQ or kill quickly), such as Duchenne's Muscular Distrophy,Cystic Fibrosis, or Down Syndrome, mean they cannot contribute to society as much as those with lesser disorders (non-lethal, doesn't affect IQ), such as Austism, ADHD, Asperegers, or being confined to a wheelchair?


Boy with Muscular Distrophy
http://blog.easystand.com/wp-content/uploads/2011/09/Donovan-Carlson-22.jpg


Girl with Cystic Fibrosis
http://livemedical.net/70-essential-facts-about-cystic-fibrosis/

vs. 


Albert Einstein (Thought to have Aspeger's or Autism)
http://en.wikipedia.org/wiki/Albert_Einstein



Stephen Hawking (invaluable to physics, astrophysics)
http://en.wikipedia.org/wiki/Albert_Einstein