Pervasive Developmental Disorder?

This is what the pediatric neurologist at Children's Mercy Says that JR has.  I have no clue.  He said that it is on the scale with autism.  JR doesn't have severe enough symptoms to be autistic, plus he interacts well with us...but he does have enough symptoms to have this.  Now I guess is my quest to figure out what this is.  Doc says the answer is therapy therapy and more therapy.  So we took him to the lab where they drew some blood and he got to pee in a cup(he thought that was cool)...and we scheduled him for an mri.  So we'll see.