Case 10 explanation

The correct answer is "Trisomy 13"

This child has trisomy 13, or Patau's syndrome.

The major midline dysmorphic features of trisomy 13 are due to a defect in the fusion of the midline precordial mesoderm in the first 3 weeks of gestation, and may include mental and motor retardation, polydactyly, microcephaly, low-set ears, holoprosencephaly, heart defects, microphthalmia, midline cleft lip and/or palate, and omphalocele. Most children affected with trisomy 13 die within the first 6 months.

Incorrects

Neural tube defects are abnormalities of the brain and spinal cord. They are associated with folic acid deficiency. Several organ systems are affected in this child, which should raise suspicion for an underlying syndrome.

Congenital rubella infection can have devastating effects on the newborn. The most common clinical findings are sensorineural deafness, ophthalmologic abnormalities (especially cataracts), cardiac manifestations including patent ductus, and meningoencephalitis.

Trisomy 18, or Edwards' syndrome, is the second most common trisomy observed in live births. Clinical manifestations include feeding difficulties, hypotonia eventually leading to hypertonia, prominent occiput, micrognathia, horseshoe kidneys, flexed fingers with overlapping fingers, congenital heart defects, and malrotation of the gastrointestinal system.

Trisomy 21, or Down's syndrome, is the most common trisomy found in live births. Clinical manifestations include upslanting palpebral fissures, epicanthal folds, small mouth with a protruding tongue, simian (transverse) palmar crease, mental retardation, flat nasal bridge, and excessive skin at the nape of the neck.