Need doctor's exam
The pierre robin sequence (prs) is diagnosed by a physician trained in classifying such abnormalities, and based on the presence, at birth, of a u-shaped cleft palate, small jaw with a receding chin, and a tongue that appears big (because of the small jaw) and is bent towards the throat.
Often, an eye exam
and a genetic study are done to check for stickler and velocardiofacial syndrome as well.
Answer assisted by Aaron Stupple, Medical Student