Review Question - QID 217157

This patient with a history of developmental delay (only speaking in 2-word phrases), neurobehavioral deficits (difficulty making friends with others), growth delay, and characteristic facies (small palpebral fissures, smooth philtrum, and thin vermillion border) most likely has fetal alcohol syndrome.

Fetal alcohol syndrome is a characteristic pattern of mental and physical defects that results from maternal use of alcohol during pregnancy. Alcohol crosses the placenta and can alter fetal development by disrupting cell differentiation and growth, DNA and protein synthesis, and cell migration. In particular, impaired migration of neuronal and glial cells may lead to intellectual disability. Other prominent symptoms include decreased muscle tone and poor motor coordination. Physical exam findings include craniofacial abnormalities (short palpebral fissures, thin vermillion border, microphthalmia, strabismus, and midfacial hypoplasia), microcephaly, and congenital heart defects. Treatment consists of education and social support for at-risk mothers.

Mattson et al. review the presentation of fetal alcohol spectrum disorders. They discuss how these disorders are associated with neurobehavioral deficits. They recommend using the neurobehavioral profile of fetal alcohol spectrum disorders as an adjunct to making the correct diagnosis.

Incorrect Answers:
Answer 2: Fetal hydantoin syndrome is a characteristic pattern of mental and physical defects that results from maternal use of phenytoin during pregnancy. Findings in fetal hydantoin syndrome can include cleft palate, microcephaly, facial dysmorphism, hirsutism, cardiac defects, hypoplastic nails, neural tube defects, and intellectual disability. However, this patient’s findings of small palpebral fissures, smooth philtrum, and thin vermillion border are more specific for fetal alcohol syndrome.

Answer 3: Fragile X syndrome is a genetic syndrome caused by trinucleotide expansion in the untranslated region of the fragile X mental retardation 1 (FMR1) gene on the X chromosome. Findings in Fragile X syndrome include profound learning disability, neurobehavioral deficits, prominent ears, long face, macrocephaly, prominent brow, high arched palate, macroorchidism, and cardiac defects.

Answer 4: Neonatal abstinence syndrome is a complex disorder involving the central nervous system, autonomic nervous system, and gastrointestinal tract that results from maternal use of opiates. Findings in neonatal abstinence syndrome include uncoordinated sucking reflexes, irritability, tremors, sneezing, diarrhea, tachypnea, and seizures. However, this condition usually resolves in the neonatal period, and maternal use of opiates would not be expected to cause either dysmorphic facial features or persistent intellectual disability.

Answer 5: Trisomy 21, also known as Down syndrome, is the most common chromosomal anomaly in humans. Findings and associations in trisomy 21 include intellectual disability, duodenal atresia, Hirschsprung disease, congenital heart disease, Brushfield spots, and early-onset Alzheimer disease. Other characteristic physical exam findings in this condition include flat facies, prominent epicanthal folds, single palmar crease, and sandal toes (a gap between 1st and 2nd toes).

Bullet Summary:
Fetal alcohol syndrome classically presents with small palpebral fissures, smooth philtrum, thin vermillion border, growth delay, and intellectual disabilities.