Autistic disorder in Noonan syndrome.

Dougherty et al. (1994) wrote up one patient. The child had Noonan syndrome and also met criteria for autism.

They used regular autism checklists. The goal was to show that both conditions can live in the same kid.

The checklists flagged clear autism traits. The authors said, "Screen every Noonan patient for autism."

No fancy numbers were given. The point was simple: do not miss the second diagnosis.

Crane et al. (2016) later tested a whole Finnish cohort. They proved that kids with genetic syndromes get autism far more often than matched peers. The single case from 1994 was no fluke.

Schwichtenberg et al. (2013) counted 19 % of Down syndrome children who also met ASD cut-off. Godfrey et al. (2019) then showed those DS+ASD kids have their own symptom profile. Together they turn the 1994 warning into a map: expect autism, but watch for syndrome-specific shapes.

Trillingsgaard et al. (2004) sounded a small alarm. In Angelman syndrome, most kids hit ASD cut-off, yet the behaviors may stem from severe delay rather than "true" autism. So screen, but interpret scores with mental age in mind.

Next time you assess a child with Noonan, pull out your autism tools as a habit. If scores are high, zoom out: check mental age, look for syndrome-specific quirks, and write goals that fit the whole picture. One extra step can move the child from missed to properly served.