My students have no previous training in dance. When children first come to my class they run around the room, spin, talk and run back and forth, any of those or other behaviors. But they smile.
In subsequent weeks they copy me a little, then more and more. The more they are able to copy, the more they smile. There is no timetable, no one is told they are doing the movement incorrectly. Each week there is a bit more participation, eventually they are dancing with me. One boy creates new movement WITH me, another loves to lead the other students in movement. Even though some science studies show there are reasons why some people can't dance or reasons why they can't relate to the world doesn't mean that they shouldn't try to dance.
In college (I won't tell you how long ago) dance was not the most respected major. Movement therapies, expressive therapies, are more common now, and I see it's critical for so many children. I see programs for children to study ballet and other forms of dance resulting in better grades, self-esteem, confidence, discipline in other areas of life.
Unfortunately, there aren't many dance classes for special needs children to have that experience in dance. But that doesn't mean it isn't important for these kids to learn to dance.
I see my students get control of their body over time, I see improvement in social skills, speech, fewer melt downs, and some just having fun with other children. Don't underestimate your autistic or child with SPD, PPD-NOS, Downs Syndrome or other special needs. Look for dance instructors, like me, who have the patience to teach ANYONE to dance.