CLINICAL REPORT Mosaic Partial Trisomy 19p12-q13.11 Due to a Small Supernumerary Marker Chromosome: A Locus Associated With Asperger Syndrome? Fabio Rueda Faucz, 1 * Josiane Souza, 1 Aguinaldo Bonalumi Filho, 1 Vanessa Santos Sotomaior, 1 Egon Frantz, 2 Sergio Antoniuk, 3 Jill A. Rosenfeld 4 and Salmo Raskin 1,5 1 Group for Advanced Molecular Investigation (NIMA), Graduate Program in Health Sciences (PPGCS), Center for Biological and Health Sciences (CCBS), Pontificia Universidade Catolica do Parana (PUCPR) Curitiba, PR, Brazil 2 Institute of Neurology, Department of Neurology, Blumenau, SC, Brazil 3 Departamento de Pediatria, Universidade Federal do Parana, Curitiba, PR, Brazil 4 Signature Genomics, Spokane, Washington 5 Laboratory Genetika, Curitiba, PR, Brazil Received 29 April 2011; Accepted 1 June 2011 In the neurodevelopmentally impaired population the frequency of small supernumerary marker chromosomes (sSMC) is about 0.3%. To find the origin of a sSMC in a 4-year-old boy with Asperger syndrome (AS) a microarray-based comparative genomic hybridization (aCGH), using a 135K-feature whole- genome microarray, and Metaphase FISH analysis, was per- formed. The sSMC was characterized as being composed of 18.4 Mb from 19p12q13.11. Based on the size and genic content, it is expected that the partial trisomy detected is responsible for the characteristics observed in the patient. In that case it could be an indication of a novel locus associated with AS. Ó 2011 Wiley-Liss, Inc. Key words: asperger syndrome; chromosome 19p12q13.11; sSMC; CGH array; FISH INTRODUCTION Small supernumerary marker chromosomes (sSMC) are structur- ally abnormal chromosomes that are found in 0.75/1,000 of unse- lected prenatal and 0.44/1,000 of unselected postnatal cases, being much more frequent among the neurodevelopmentally impaired (2.88/1,000) [Liehr and Weise, 2007]. When found de novo prenatally, there is a 26% risk of phenotypic abnormalities [Graf et al., 2006]. Molecular cytogenetic techniques characterize the size and gene content of sSMCs, which allows for a more informed interpretation of their potential phenotypic impact. Here we report on a 4-year-old boy with Asperger syndrome (AS) and sSMC leading to mosaic partial trisomy 19p12q13.11. MATERIALS AND METHODS Conventional Cytogenetic Twenty cells from the patient and both parents were analyzed using G-banded metaphase chromosomes, which was obtained from blood. Oligonucleotide-Based aCGH Microarray-based comparative genomic hybridization (aCGH) was performed (in the patient only) using a 135K-feature whole-genome microarray (SignatureChip Oligo SolutionÔ, custom-designed by Signature Genomic Laboratories, made by Roche NimbleGen, Madison, WI), according to previously described methods [Duker et al., 2010]. Fluorescence In Situ Hybridization (FISH) Analysis Metaphase FISH analysis was performed using BAC clones RP11- 587H3 from 19p12 and RP11-96A7 from 19q12 to visualize the abnormalities, according to previously described methods [Traylor et al., 2009]. *Correspondence to: Fabio Rueda Faucz, PhD, Pontificia Universidade Catolica do Parana (PUCPR) NIMA/PPGCS/CCBS. Rua Imaculada Conceicao, 1155, Prado Velho, 80215-901 Curitiba, PR, Brazil. E-mail: fabio.faucz@pucpr.br, fruedas@onda.com.br Published online 00 Month 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ajmg.a.34196 How to Cite this Article: Faucz FR, Souza J, Filho AB, Sotomaior VS, Frantz E, Antoniuk S, Rosenfeld JA, Raskin S. 2011. Mosaic partial trisomy 19p12-q13.11 due to a small supernumerary marker chromosome: A locus associated with asperger syndrome? Am J Med Genet Part A 9999:1–3. Ó 2011 Wiley-Liss, Inc. 1