A preterm neonate has clenched hands with the index finger overlapping the third finger, rocker-bottom feet, micrognathia, and low-set ears. Echocardiography shows a ventricular septal defect. Which chromosomal abnormality should be suspected?
- A Trisomy 18 ✓
- B Trisomy 13
- C Trisomy 21
- D 22q11.2 microdeletion
Correct answer: A. Trisomy 18
Explanation
Overlapping flexed fingers (index over third, fifth over fourth), rocker-bottom feet, micrognathia, and growth restriction are the signature findings of Edwards syndrome, trisomy 18. Trisomy 13 (Patau) is distinguished by midline defects including holoprosencephaly, cleft lip and palate, polydactyly, and ocular anomalies, none of which are described here. Trisomy 21 shows upslanting palpebral fissures and a single palmar crease instead.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.