In Advocacy Realm, Specific Disabilities Gain in Prominence

Groups that advocate on behalf of specific disabilities are proliferating, fueled by a medical establishment that can trace disorders down to their very genes and a communication system that can easily connect people around the globe.

But some advocates worry that too much focus on autism or Down syndrome, even on the presidential-campaign trail, could distract from efforts to support common issues that affect many groups.

The issue is of particular concern in education, because many of the accommodation, inclusion, and differentiated-instruction efforts in schools have the potential to cut...