CRIG Case Reports in Genetics 2090-6552 2090-6544 Hindawi Publishing Corporation 10.1155/2015/474097 474097 Case Report PWS/AS MS-MLPA Confirms Maternal Origin of 15q11.2 Microduplication Dawson Angelika J. adawson@dsmanitoba.ca 1,2,3 http://orcid.org/0000-0003-2902-2791 Cox Janice jcox1@dsmanitoba.ca 4 Hovanes Karine khovanes@combimatrix.com 5 http://orcid.org/0000-0002-5047-1906 Spriggs Elizabeth bspriggs@dsmanitoba.ca 2,3,4 Ban Yoshiyuki 1 Cytogenetic Laboratory, HSC Diagnostic Services of Manitoba 820 Sherbrook Street, Winnipeg, MB Canada R3A 1K9 dsmanitoba.ca 2 Departments of Biochemistry & Medical Genetics and Pediatrics & Child Health University of Manitoba Winnipeg, MB Canada R3E 0J9 umanitoba.ca 3 Genetics & Metabolism Program WRHA Winnipeg, MB Canada R3A 1R9 wrha.mb.ca 4 Molecular Diagnostic Laboratory, HSC Diagnostic Services of Manitoba 820 Sherbrook Street, Winnipeg, MB Canada R3A 1K9 dsmanitoba.ca 5 CombiMatrix Diagnostics 310 Goddard, Suite 150, Irvine, CA 92618 USA combimatrix.com 2015 752015 2015 09 12 2014 21 04 2015 752015 2015 Copyright © 2015 Angelika J. Dawson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The proximal region of the long arm of chromosome 15q11.2-q13 is associated with various neurodevelopmental disorders, including Prader-Willi (PWS) and Angelman (AS) syndromes, autism, and other developmental abnormalities resulting from deletions and duplications. In addition, this region encompasses imprinted genes that cause PWS or AS, depending on the parent-of-origin. This imprinting allows for diagnosis of PWS or AS based on methylation status using methylation sensitive (MS) multiplex ligation dependent probe amplification (MLPA). Maternally derived microduplications at 15q11.2-q13 have been associated with autism and other neuropsychiatric disorders. Multiple methods have been used to determine the parent-of-origin for 15q11.2-q13 microdeletions and microduplications. In the present study, a four-year-old nondysmorphic female patient with developmental delay was found to have a de novo ~5 Mb duplication within 15q11.2 by oligonucleotide genomic array. In order to determine the significance of this microduplication to the clinical phenotype, the parent-of-origin needed to be identified. The PWS/AS MS-MLPA assay is generally used to distinguish between deletion and uniparental disomy (UPD) of 15q11.2-q13, resulting in either PWS or AS. However, our study shows that PWS/AS MS-MLPA can also efficiently distinguish the parental origin of duplications of 15q11.2-q13.