title: Pallister-Killian syndrome: a study of 22 British patients.
abstract: BACKGROUND
  Pallister-Killian syndrome is a rare, sporadic condition caused by mosaic tetrasomy of the short arm of chromosome 12 (12p). The main features are intellectual disability, seizures, dysmorphic features and a variety of congenital malformations. Most available information comes from individual case reports. We report the results of a British study into Pallister-Killian syndrome, which is the first to provide comprehensive data on a population-based sample.
  
  
  METHODS
  A detailed phenotypical study was carried out in Great Britain. All individuals with Pallister-Killian syndrome were eligible to participate. Each participant underwent a structured history, developmental assessment and clinical examination. Buccal mucosal samples were analysed by interphase fluorescence in situ hybridization (FISH) and blood samples by array comparative genomic hybridization (CGH). Genotype-phenotype correlations were sought in these tissues and existing skin biopsy reports.
  
  
  RESULTS
  Twenty-two patients with Pallister-Killian syndrome, ranging from 4 months to 31 years were recruited and comprehensive data on each obtained. The birth incidence was 5.1 per million live births. Array CGH only suggested the diagnosis in 15.8% but buccal FISH could have made the diagnosis in 75.0%. There was no genotype-phenotype correlation in any of the tissues studied. This study shows that the high birth weights and profound intellectual disability classically described in Pallister-Killian syndrome are not universal. Mild or moderate intellectual disability was present in 27.6% of this cohort and all birth weights were within 2.67SD of the mean. New features which have not previously been recognised as part of Pallister-Killian syndrome include anhydrosis/hypohydrosis and episodic hyperventilation, suggesting involvement of the autonomic system.
authors.affiliation: Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds, UK.
authors.forename: Moira
authors.initials: M
authors.lastname: Blyth
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK.
authors.forename: Viv
authors.initials: V
authors.lastname: Maloney
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Beal
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK.
authors.forename: Morag
authors.initials: M
authors.lastname: Collinson
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester.
authors.forename: Shuwen
authors.initials: S
authors.lastname: Huang
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK.
authors.forename: John
authors.initials: J
authors.lastname: Crolla
authors.affiliation: Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton, UK Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK.
authors.forename: I Karen
authors.initials: IK
authors.lastname: Temple
authors.affiliation: Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton, UK Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Baralle
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D025063:Chromosome Disorders / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics* / Q000473:pathology; D009030:Mosaicism; D010641:Phenotype; D058670:Tetrasomy / Q000235:genetics / Q000473:pathology*; D006113:United Kingdom / Q000453:epidemiology
keywords: Chromosomal; Clinical genetics