[Uberfuhrer]

I'm going to assume that an ISTJ autistic would less likely be diagnosed, because as an SJ, the ISTJ is more cooperative to the norms of society. Same goes for an INFJ autistic, who is likely to be the kind of autistic that has trouble fitting in with a group.

The INTJ, on the other hand, as a highly utilitarian type, is more likely to be diagnosed for being a disruption to the school environment, which is when most kids become diagnosed with their respective "disabilities." And unlike the INFJ autistic, the INTJ would less likely be interested in fitting into a group.