CLINICAL BRIEF Mosaic Trisomy 9 Presenting with Congenital Heart Disease, Facial Dysmorphism and Pigmentary Skin Lesions: Intricate Issues of Genetic Counseling Siddram J. Patil & Rajitha Ponnala & Sejal Shah & Ashwin Dalal Received: 29 October 2010 / Accepted: 27 September 2011 / Published online: 6 October 2011 # Dr. K C Chaudhuri Foundation 2011 Abstract 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 manifes- tations (facial dysmorphism, various internal organ malfor- mations and severe psychomotor retardation), pigmentary mosaic skin lesions along the lines of Blaschko and evidence of maternal uniparental disomy in skin. Keywords Mosaic trisomy 9 . Congenital heart disease . Pigmentary mosaic skin lesions Introduction Full aneuploidy for certain chromosomes is lethal in- utero; mosaicism is the only way for long term survival in such cases. In majority, complete trisomy 9 results in first trimester spontaneous abortion and is rarely seen in live-born infants with multiple malformations and results in early death. Mosaicism for trisomy 9 is an uncommon chromosomal abnormality, associated with prolonged survival and variable clinical features [1, 2]. The authors report a female child of mosaic trisomy 9 with congenital heart defect (CHD), mosaic pigmentary skin lesions and early death. Case Report An one-mo-old female child, born at full term and having birth weight of 3 kg, presented with CHD and pigmentary skin lesions along the lines of Blaschko. Mother had history of 3 first trimester abortions and has one normal living female child. On examination, the child had upslant palpebral fissures, prominent wide nose with bulbous nasal tip, small palpebral fissures, low set posteriorly angulated ears, small ears with overfolded helix, small mouth, high arch palate, micrognathia, broad alveolar ridges, mosaic pigmen- tary skin lesions and bilateral single transverse crease (Figs. 1 and 2). Cardiac 2D echocardiography revealed complex heart malformation featuring atrial and ventricular septal defect, and possible coarctation of aorta. Anthropometric S. J. Patil (*) Department of Clinical Genetics, Centre for Molecular and Metabolic Diagnostics & Research Narayana Hrudayalaya Institute of Medical Sciences, Narayana Hrudayalaya Health City, No 258/A, Bommasandra Industrial Area, Anekal Taluq, Bangalore 560099, India e-mail: drsjpatil@gmail.com R. Ponnala : A. Dalal Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India S. Shah Department of Pediatric cardiology, Narayana Hrudayalaya Institute of Medical Sciences, Bangalore, India Indian J Pediatr (June 2012) 79(6):806–809 DOI 10.1007/s12098-011-0567-x