title: Novel mutation-deletion in thePHOX2Bgene of the patient diagnosed with Neuroblastoma, Hirschsprung's Disease, and Congenital Central Hypoventilation Syndrome (NB-HSCR-CCHS) Cluster.
abstract: BACKGROUND
  Neuroblastoma (NB), Hirschsprung disease (HSCR), Congenital Central Hypoventilation Syndrome (CCHS), clinically referred as the NB-HSCR-CCHS cluster, are genetic disorders linked to mutations in thePHOX2Bgene on chromosome 4p12.
  
  
  OBJECTIVE
  The specific aim of this project is to define thePHOX2Bgene mutations as the genomic basis for the clinical manifestations of the NB-HSCR-CCHS cluster.
  
  
  METHODS
  A one day old male patient presented to the Jagiellonian University Medical College (JUMC), American Children Hospital, neonatal Intensive Care Unit (ICU) due to abdominal distention, vomiting, and severe apneic episodes. With the preliminary diagnosis of the NB-HSCR-CCHS, the blood and tissue samples were acquired from the child, as well as from the child's parents. All procedures were pursued in accordance with the Declaration of Helsinki, with the patient's Guardian Informed Consent and the approval from the Institutional Review Board.
  Karyotyping was analyzed based upon Giemsa banding. The patient's genomic DNA was extracted from peripheral blood and amplified by polymerase chain reaction. Direct microfluidic Sanger sequencing was performed on the genomic DNA amplicons. These procedures were pursued in addition to the routine clinical examinations and tests.
  
  
  RESULTS
  G-banding showed the normal 46 XY karyotype. However, genomic sequencing revealed a novel, heterozygous deletion (8 nucleotides: c.699-706, del8) in exon 3 of thePHOX2Bgene on chromosome 4. This led to the frame-shift mutation and malfunctioning gene expression product.
  
  
  CONCLUSIONS
  Herein, we report a novelPHOX2Bgene mutation in the patient diagnosed with the NB-HSCR-CCHS cluster. The resulting gene expression product may be a contributor to the clinical manifestations of these genetic disorders. It adds to the library of the mutations linked to this syndrome. Consequently, we suggest that screening for thePHOX2Bmutations becomes an integral part of genetic counseling, genomic sequencing of fetal circulating nucleic acids and / or genomes of circulating fetal cells prenatally, while preparing supportive therapy upon delivery, as well as on neonates' genomes of intubated infants, when breathing difficulties occur upon extubation. Further, we hypothesize thatPHOX2Bmay be considered as a potential target for gene therapy.
authors.affiliation: Department of Pediatrics, Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Izabela
authors.initials: I
authors.lastname: Szymońska
authors.affiliation: Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Thore Langfeldt
authors.initials: TL
authors.lastname: Borgenvik
authors.affiliation: Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Tina Margrethe
authors.initials: TM
authors.lastname: Karlsvik
authors.affiliation: Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Anders
authors.initials: A
authors.lastname: Halsen
authors.affiliation: Jagiellonian University Medical College, Krakow, Poland, EU; Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA.
authors.forename: Bianka Kathryn
authors.initials: BK
authors.lastname: Malecki
authors.affiliation: Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Sindre Ervik
authors.initials: SE
authors.lastname: Saetre
authors.affiliation: Department of Pediatrics, Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Jagła
authors.affiliation: Department of Pediatrics, Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kruczek
authors.affiliation: Department of Clinical Genetics, Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Anna Madetko
authors.initials: AM
authors.lastname: Talowska
authors.affiliation: Department of Pathology, Children's University Hospital, Kraków, Poland, EU.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Drabik
authors.affiliation: Department of Pediatrics, Jagiellonian University Medical College, Krakow, Poland, EU.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zasada
authors.affiliation: Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA; NMRFM, National Institutes of Health, Madison, WI, USA; University of Wisconsin, Madison, WI, USA.
authors.forename: Marek
authors.initials: M
authors.lastname: Malecki
keywords: 4p12; Aganglionosis of the Terminal Bowel (ATB); Congenital Central Hypoventilation Syndrome (CCHS); Haddad syndrome; Hirschsprung’s disease (HSCR); NB-HSCR-CCHS; Neuroblastoma (NB); Neurocristopathy; PHOX2B; SOX10; deletion; mutation