Facial dysmorphia
On the basis of racial norms, the person exhibits all three of the following facial features:
	Smooth philtrum (University of Washington Lip-Philtrum Guide rank 4 or 5)
	Thin vermilion border (University of Washington Lip-Philtrum Guide rank 4 or 5)
	Small palpebral fissures (≤10th percentile)
Growth problems
Prenatal or postnatal height, weight, or both ≤10th percentile, adjusted for age, sex, gestational age, and race or ethnicity
Central nervous system abnormalities
Structural
	Head circumference ≤10th percentile, adjusted for age and sex
	Clinically meaningful brain abnormalities observed through imaging
Neurologic
	Neurologic problems not resulting from a postnatal insult or fever, or other soft neurologic signs outside normal limits
Functional
	Test performance substantially below that expected for a person’s age, schooling, or circumstances, as evidenced by global cognitive or intellectual deficits representing multiple domains of deficit (or substantial developmental delay in younger children), with performance below the third percentile (i.e., 2 SDs below the mean for standardized testing); or functional deficits < 16th percentile (i.e., 1 SD below the mean for standardized testing) in at least three of the following domains:
	Cognitive or developmental deficits or discrepancies
	Executive functioning deficits
	Motor functioning delays
	Problems with attention or hyperactivity
	Problems with social skills
	Other problems (e.g., sensory problems, pragmatic language problems, memory deficits)