title: Parent-of-origin testing for 15q11-q13 gains by quantitative DNA methylation analysis.
abstract: The Prader-Willi/Angelman syndrome critical region (PWS/ASCR), located at chromosome 15q11-q13, is associated with several diseases. Absence of paternally expressed genes in this region cause Prader-Willi syndrome (PWS), whereas absence of the maternally expressed UBE3A gene causes Angelman syndrome (AS). In addition, duplications and triplications of this region are also associated with distinct clinical features, indicating that the overexpression of genes within the PWS/ASCR can also lead to distinct phenotypes. Maternally inherited increases in copy number generally lead to a more severe phenotype do than paternally inherited increases. We describe a real-time methylation-sensitive PCR (Q-MSP) assay that quantifies methylation at the promoter of the differentially methylated SNRPN gene located within the PWS/ASCR. Q-MSP can detect both PWS and AS, as well as determine the parent of origin for the allele that carries the PWS/ASCR gains. In addition, Q-MSP requires only a small amount of DNA, is amenable to high-throughput analysis, and can be used in clinical testing as a reflex test to determine the parent of origin after identification of a gain of this region on chromosome 15.
authors.affiliation: Emory Genetics Laboratory, Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: S Hussain
authors.initials: SH
authors.lastname: Askree
authors.forename: Shika
authors.initials: S
authors.lastname: Dharamrup
authors.forename: Lawrence N
authors.initials: LN
authors.lastname: Hjelm
authors.forename: Bradford
authors.initials: B
authors.lastname: Coffee
mesh_terms: D017204:Angelman Syndrome / Q000175:diagnosis* / Q000235:genetics; D001483:Base Sequence; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D004247:DNA / Q000235:genetics; D056915:DNA Copy Number Variations; D019175:DNA Methylation; D005820:Genetic Testing; D057166:High-Throughput Screening Assays; D006801:Humans; D010290:Parents; D011218:Prader-Willi Syndrome / Q000175:diagnosis* / Q000235:genetics; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D017422:Sequence Analysis, DNA; D044767:Ubiquitin-Protein Ligases / Q000172:deficiency / Q000235:genetics; D055517:snRNP Core Proteins / Q000235:genetics
chemical_list: C526417:SNRPN protein, human; D055517:snRNP Core Proteins; D004247:DNA; C471639:UBE3A protein, human; D044767:Ubiquitin-Protein Ligases