A newborn delivered preterm has low-set malformed ears, micrognathia, flexed overlapping fingers with the index finger overriding the third, and rocker-bottom feet. Echocardiography shows a ventricular septal defect. Which trisomy is most likely?
- A Trisomy 21
- B Trisomy 18 ✓
- C Trisomy 13
- D Trisomy 9p
Correct answer: B. Trisomy 18
Explanation
Edwards syndrome (trisomy 18) is characterized by clenched fists with overlapping fingers, rocker-bottom feet, micrognathia, low-set ears, and congenital heart disease, predominantly ventricular septal defect. Survival beyond the first year is uncommon. Trisomy 13 (Patau syndrome) is distinguished by midline defects including holoprosencephaly, cleft lip and palate, polydactyly, and ocular anomalies rather than the clenched-hand posture. Trisomy 21 shows hypotonia with single palmar crease and sandal gap.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.