Small head, hands and feet?

I'm 5 ft 6 -1/2, 170 lbs. 27 yrs old and I have curvature of the spine. I was very short until I hit my last growth spurt in my teen years. I've been diagnosed with mild Asperger's syndrome tho I do not show all of the symptoms so I'm not sure if the diagnosis is accurate. What I want to know is what could be the genetic disorder behind my small head, hands, and feet?