title: Pallister-Killian syndrome: Cytogenetics and molecular investigations of mosaic tetrasomy 12p in prenatal chorionic villus and in amniocytes. Strategy of prenatal diagnosis.
abstract: OBJECTIVE
  Pallister-Killian syndrome (PKS) is a rare, sporadic genetic disorder caused by mosaic tetrasomy of the short arm of chromosome 12 (12p). Clinically, PKS is characterized by several systemic abnormalities, such as intellectual impairment, hearing loss, epilepsy, hypotonia, craniofacial dysmorphism, pigmentary skin anomalies, epilepsy, and a variety of congenital malformations. Prenatally, PKS can be suspected in the presence of ultrasound anomalies: diaphragmatic hernia, rhizomelic micromelia, hydrops fetalis, fetal overweight, ventriculomegaly in the central nervous system, congenital heart defects, or absent visualization of the stomach. In all these cases, a detailed genetic study is required. PKS is diagnosed by prenatal genetic analysis through chorionic villus sampling, genetic amniocentesis, and cordocentesis.
  
  
  METHODS
  We report two cases of PKS with prenatal diagnosis of isochromosome 12p made by cytogenetic studies. The first case is of a 36-year-old pregnant woman who underwent genetic chorionic villus sampling at 13thweeks of gestation after 1sttrimester prenatal ultrasound revealed clinical features of PKS: flat nasal bridge and fetal hydrops. The second case is of a 32-year-old pregnant woman with genetic amniocentesis at 17thweeks of gestation that showed mos46,XX[21]/47,XX,+i(12p) associated to PKS.
  
  
  CONCLUSIONS
  New molecular cytogenetic techniques array comparative genomic hybridization and fluorescence in-situ hybridization in association with conventional karyotype are pivotal innovative tools to search for chromosomic anomalies and for a complete prenatal diagnosis, especially in cases such as PKS where array comparative genomic hybridization analysis alone could not show mosaicism of i(12p).
authors.affiliation: Department of Genetics, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Libotte
authors.affiliation: Department of Genetics, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Bizzoco
authors.affiliation: Department of Genetics, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Gabrielli
authors.affiliation: Department of Genetics, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Mesoraca
authors.affiliation: Department of Prenatal Diagnosis, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cignini
authors.affiliation: Department of Human Pathology in Adulthood and Childhood "G. Barresi", University of Messina, Messina, Italy. Electronic address: vitalesalvatore@hotmail.com.
authors.forename: Salvatore Giovanni
authors.initials: SG
authors.lastname: Vitale
authors.affiliation: Department of General Surgery and Medical Surgical Specialties, University of Catania, Catania, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Marilli
authors.affiliation: Department of General Surgery and Medical Surgical Specialties, University of Catania, Catania, Italy.
authors.forename: Ferdinando Antonio
authors.initials: FA
authors.lastname: Gulino
authors.affiliation: Department of General Surgery and Medical Surgical Specialties, University of Catania, Catania, Italy.
authors.forename: Agnese Maria Chiara
authors.initials: AM
authors.lastname: Rapisarda
authors.affiliation: Department of Prenatal Diagnosis, Altamedica Fetal Maternal Medical Centre, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Giorlandino
mesh_terms: D000649:Amniocentesis; D015193:Chorionic Villi Sampling; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics*; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D055028:Comparative Genomic Hybridization; D017218:Cordocentesis; D005260:Female; D005820:Genetic Testing / Q000379:methods*; D005865:Gestational Age; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D011247:Pregnancy; D058670:Tetrasomy; D016216:Ultrasonography, Prenatal; D055815:Young Adult
keywords: Pallister–Killian syndrome; cytogenetic analysis; isochromosome 12p; prenatal diagnosis; tetrasomy 12p