title: De novo interstitial duplication of the 15q11.2-q14 PWS/AS region of maternal origin: Clinical description, array CGH analysis, and review of the literature.
abstract: The 15q11-q13 PWS/AS critical region involves genes that are characterized by genomic imprinting. Multiple repeat elements within the region mediate rearrangements, including interstitial duplications, interstitial triplications, and supernumerary isodicentric marker chromosomes, as well as the deletions that cause Prader-Willi syndrome (PWS) and Angelman syndrome (AS). Recently, duplications of maternal origin concerning the same critical region have been implicated in autism spectrum disorders (ASD). We present a 6-month-old girl carrying a de novo duplication of maternal origin of the 15q11.2-q14 PWS/AS region (17.73 Mb in size) [46,XX,dup(15)(q11.2-q14)] detected with a high-resolution microarray-based comparative genomic hybridization (array-CGH). The patient is characterized by severe hypotonia, obesity, microstomia, long eyelashes, hirsutism, microretrognathia, short nose, severe psychomotor retardation, and multiple episodes of drug-resistant epileptic seizures, while her brain magnetic resonance imaging (MRI) documented partial corpus callosum dysplasia. In our patient the duplicated region is quite large extending beyond the Prader-Willi-Angelman critical region (PWACR), containing a number of genes that have been shown to be involved in ASD, exhibiting a severe phenotype, beyond the typical PWS/AS clinical manifestations. Reporting of similar well-characterized clinical cases with clearly delineated breakpoints of the duplicated region will clarify the contribution of specific genes to the phenotype.
authors.affiliation: Department of Medical Genetics, Medical School, University of Athens, Athens, Greece.
authors.forename: Sophia
authors.initials: S
authors.lastname: Kitsiou-Tzeli
authors.forename: Maria
authors.initials: M
authors.lastname: Tzetis
authors.forename: Christalena
authors.initials: C
authors.lastname: Sofocleous
authors.forename: Christina
authors.initials: C
authors.lastname: Vrettou
authors.forename: Athena
authors.initials: A
authors.lastname: Xaidara
authors.forename: Krinio
authors.initials: K
authors.lastname: Giannikou
authors.forename: Andreas
authors.initials: A
authors.lastname: Pampanos
authors.forename: Ariadne
authors.initials: A
authors.lastname: Mavrou
authors.forename: E
authors.initials: E
authors.lastname: Kanavakis
mesh_terms: D017204:Angelman Syndrome / Q000235:genetics* / Q000473:pathology; D002869:Chromosome Aberrations; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D005260:Female; D020440:Gene Duplication; D018392:Genomic Imprinting; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D009035:Mothers; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011218:Prader-Willi Syndrome / Q000235:genetics* / Q000473:pathology