title: PWS/AS MS-MLPA Confirms Maternal Origin of 15q11.2 Microduplication.
abstract: 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.
authors.affiliation: Cytogenetic Laboratory, HSC, Diagnostic Services of Manitoba, 820 Sherbrook Street, Winnipeg, MB, Canada R3A 1K9 ; Departments of Biochemistry & Medical Genetics and Pediatrics & Child Health, University of Manitoba, Winnipeg, MB, Canada R3E 0J9 ; Genetics & Metabolism Program, WRHA, Winnipeg, MB, Canada R3A 1R9.
authors.forename: Angelika J
authors.initials: AJ
authors.lastname: Dawson
authors.affiliation: Molecular Diagnostic Laboratory, HSC, Diagnostic Services of Manitoba, 820 Sherbrook Street, Winnipeg, MB, Canada R3A 1K9.
authors.forename: Janice
authors.identifier: 0000-0003-2902-2791
authors.initials: J
authors.lastname: Cox
authors.affiliation: CombiMatrix Diagnostics, 310 Goddard, Suite 150, Irvine, CA 92618, USA.
authors.forename: Karine
authors.initials: K
authors.lastname: Hovanes
authors.affiliation: Departments of Biochemistry & Medical Genetics and Pediatrics & Child Health, University of Manitoba, Winnipeg, MB, Canada R3E 0J9 ; Genetics & Metabolism Program, WRHA, Winnipeg, MB, Canada R3A 1R9 ; Molecular Diagnostic Laboratory, HSC, Diagnostic Services of Manitoba, 820 Sherbrook Street, Winnipeg, MB, Canada R3A 1K9.
authors.forename: Elizabeth
authors.identifier: 0000-0002-5047-1906
authors.initials: E
authors.lastname: Spriggs