A 3-year-old child has intrauterine growth restriction, short stature, body asymmetry, and characteristic triangular face with a prominent forehead. Which chromosomal abnormality is most likely?
- A Paternal uniparental disomy of chromosome 15
- B Maternal uniparental disomy of chromosome 7 ✓
- C Deletion of 22q11.2
- D Trisomy 18
Correct answer: B. Maternal uniparental disomy of chromosome 7
Explanation
The vignette describes Russell-Silver syndrome, characterized by intrauterine growth restriction, short stature, body asymmetry, and a triangular face with prominent forehead. The most common molecular mechanism is maternal uniparental disomy of chromosome 7 (in about 10%) or imprinting defect on chromosome 11p15. Paternal UPD 15 causes Prader-Willi syndrome. 22q11.2 deletion causes DiGeorge syndrome. Trisomy 18 causes Edwards syndrome.
Reference: Smith's Recognizable Patterns of Human Malformation, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.