Fetal Alcohol Syndrome
Several characteristic craniofacial abnormalities are often visible in individuals with FAS.[25] The presence of FAS facial features indicates brain damage, though brain damage may also exist in their absence. FAS facial features (and most other visible, but non-diagnostic, deformities) are believed to be caused mainly during the 10th and 20th week of gestation.[26]
Refinements in diagnostic criteria since 1975 have yielded three distinctive and diagnostically significant facial features known to result from prenatal alcohol exposure and distinguishes FAS from other disorders with partially overlapping characteristics.[27][28] The three FAS facial features are:
A smooth philtrum — The divot or groove between the nose and upper lip flattens with increased prenatal alcohol exposure.
Thin vermilion — The upper lip thins with increased prenatal alcohol exposure.
Small palpebral fissures — Eye width decreases with increased prenatal alcohol exposure.
The four diagnostic systems list various CNS domains that can qualify for functional impairment that can determine an FAS diagnosis:
Evidence of a complex pattern of behavior or cognitive abnormalities inconsistent with developmental level in the following CNS domains — sufficient for a PFAS (partial fetal alcohol syndrome) or ARND (alcohol-related neurodevelopmental disorder) diagnosis using IOM guidelines[20]
Learning disabilities, academic achievement, impulse control, social perception, communication, abstraction, math skills, memory, attention, judgment
Performance at two or more standard deviations on standardized testing in three or more of the following CNS domains — sufficient for a FAS, PFAS or static encephalopathy diagnosis using 4-Digit Diagnostic Code[11]
Executive functioning, memory, cognition, social/adaptive skills, academic achievement, language, motor skills, attention, activity level
General cognitive deficits (e.g., IQ) at or below the 3rd percentile on standardized testing — sufficient for an FAS diagnosis using CDC guidelines[23]
Performance at or below the 16th percentile on standardized testing in three or more of the following CNS domains — sufficient for an FAS diagnosis using CDC guidelines[23]
Cognition, executive functioning, motor functioning, attention and hyperactive problems, social skills, sensory integration dysfunction, social communication, memory, difficulties responding to common parenting practices
Performance at two or more standard deviations on standardized testing in three or more of the following CNS domains — sufficient for an FAS diagnosis using Canadian guidelines
Cognition, communication, academic achievement, memory, executive functioning, adaptive behavior, social skills, social communication
