Mosaic Trisomy 9 Presenting with Congenital Heart Disease, Facial Dysmorphism and Pigmentary Skin Lesions: Intricate Issues of Genetic Counseling

Chromosomal mosaicism for full aneuploidy involving chromosome 9 is an uncommon chromosomal abnormality. Mosaic trisomy 9 clinical manifestations are highly variable and difficult to predict. The authors present a case of mosaic trisomy 9 with typical clinical manifestations (facial dysmorphism, various internal organ malformations and severe psychomotor retardation), pigmentary mosaic skin lesions along the lines of Blaschko and evidence of maternal uniparental disomy in skin.