title: Periventricular nodular heterotopia in Smith-Magenis syndrome.
abstract: Smith-Magenis syndrome (SMS) is caused by an interstitial microdeletion of chromosome 17p11.2. A few patients with the typical SMS phenotype have RAI1 gene mutations. The syndrome is characterized by minor craniofacial anomalies, short stature, sleep disturbances, behavioural and neurocognitive abnormalities, as well as variable multisystemic manifestations. Periventricular nodular heterotopia (PNH) is a genetically heterogeneous neuronal migration disorder characterized by subependymal heterotopic nodules, and is variably associated with other brain malformations, epileptic seizures and intellectual disability. Here we report on two patients harboring deletions of the 17p11.2 region in whom the SMS typical phenotype was associated with bilateral PNH. Our observations expand the spectrum of chromosomal rearrangements associated with PNH and indicate that abnormal neuronal migration may contribute to the neurocognitive phenotype of SMS.
authors.affiliation: Neurosurgery Unit, Istituto Giannina Gaslini, 16147 Genova, Genoa, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Capra
authors.forename: Roberta
authors.initials: R
authors.lastname: Biancheri
authors.forename: Giovanni
authors.initials: G
authors.lastname: Morana
authors.forename: Pasquale
authors.initials: P
authors.lastname: Striano
authors.forename: Francesca
authors.initials: F
authors.lastname: Novara
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Ferrero
authors.forename: Luca
authors.initials: L
authors.lastname: Boeri
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Celle
authors.forename: Maria Margherita
authors.initials: MM
authors.lastname: Mancardi
authors.forename: Orsetta
authors.initials: O
authors.lastname: Zuffardi
authors.forename: Elena
authors.initials: E
authors.lastname: Parrini
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
mesh_terms: D000293:Adolescent; D001921:Brain / Q000000981:diagnostic imaging; D002675:Child, Preschool; D002872:Chromosome Deletion; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D054091:Periventricular Nodular Heterotopia / Q000473:pathology*; D011859:Radiography; D058496:Smith-Magenis Syndrome / Q000473:pathology*
keywords: 17p11.2 chromosomal deletion; Periventricular nodular heterotopia (PNH); Smith-Magenis syndrome (SMS)