A neonate born at 38 weeks has low-set ears, micrognathia, flexion deformities of the fingers with overriding index finger over the third, rocker-bottom feet, and apnoeic spells. Echocardiography shows a ventricular septal defect. Which chromosome abnormality is most likely?

• A Trisomy 18 ✓
• B Trisomy 13
• C Trisomy 9
• D Trisomy 8 mosaicism

Explanation

Trisomy 18 (Edwards syndrome) is characterised by clenched hands with overlapping fingers (index over third), rocker-bottom feet, micrognathia, low-set malformed ears, prominent occiput, growth restriction, and congenital heart disease, most commonly VSD. Survival beyond infancy is uncommon. Rocker-bottom feet also occur in trisomy 13, but trisomy 13 instead features midline defects such as cleft lip and palate, holoprosencephaly, and polydactyly, which are absent here.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.