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Case #15
Subject: Embryology
Medcloud™
Case #15
Subject: Embryology
B. Webbed neck – 2%
A webbed neck is a characteristic finding in individuals with Turner syndrome. Although low birth weight and heart murmurs can also be present in newborns with Turner syndrome, features such as microcephaly, cutis aplasia, cleft lip, rocker-bottom feet, omphalocele, and holoprosencephaly are not associated with this condition. Moreover, Turner syndrome typically presents with lymphedema of the hands and feet, nail dysplasia, and a high-arched palate, none of which are seen here. This newborn's presentation is more consistent with trisomy 13, which is not associated with a webbed neck.
C. Single palmar crease – 5%
A single palmar crease is a characteristic finding in individuals with trisomy 21 (Down syndrome). Although low birth weight and heart murmurs can also be present in newborns with trisomy 21, features such as cutis aplasia, cleft lip, rocker-bottom feet, and holoprosencephaly are not associated with this diagnosis. Moreover, trisomy 21 typically presents with further characteristics such as epicanthal folds, a broad and flat nasal bridge, sandal gap deformity, and muscle hypotonia, none of which are described in this newborn. Her presentation is more consistent with trisomy 13, which is not associated with a single palmar crease.
D. Overlapping fingers - 21%
Clenched fists with overlapping fingers (2nd and 5th fingers overlap 3rd and 4th fingers, respectively) are a characteristic finding in children with trisomy 18. Although some of the features seen in this newborn can also be present in trisomy 18 (e.g., microcephaly, cleft lip, rocker-bottom feet, omphalocele, heart murmur), the presence of cutis aplasia and holoprosencephaly is more consistent with trisomy 13, which is not associated with overlapping fingers.
E. Hypoplastic philtrum - 11%
A hypoplastic philtrum is a characteristic finding in individuals with fetal alcohol syndrome (FAS). Although some of the features seen in this newborn can also be present in FAS (e.g., low birth weight, microcephaly, heart murmur, holoprosencephaly), findings such as cutis aplasia, cleft lip, rocker-bottom feet, and omphalocele are not associated with this diagnosis. Moreover, FAS typically presents with down-slanting, short palpebral fissures, and hypertelorism, none of which are seen in this newborn. Her presentation is more consistent with trisomy 13, which is not associated with a hypoplastic philtrum.
Medcloud™
Case #16
Subject: Embryology
A 38-year-old woman, gravida 3, para 2, at 12 weeks' gestation comes to her obstetrician for a prenatal visit. Screening tests in the first trimester showed a decreased level of pregnancy-associated plasma protein and an increased level of β-human chorionic gonadotropin. A genetic disorder is suspected. Which of the following results from an additional diagnostic test is most appropriate to confirm the diagnosis at this time?