An unusual combination of trisomy 21 and partial trisomy 5q

The authors describe a male newborn with multiple congenital anomalies; craniofacial dysmorphism, bilateral cleft palate and lip, ambiguous external genitalia with absence of phallus, ventricular septal defect, agenesis of olfactory bulbs, and presence of small round cells simulating migration defect in the cerebellar white matter. Cytogenetic study demonstrated a chromosomal constitution of 47,XY, +21, +5q. Its pathological significance compared with Down's syndrome and hitherto reported partial trisomy 5q is discussed.