title: Two cases of deletion 2q37 associated with segregation of an unbalanced translocation 2;21: choanal atresia leading to misdiagnosis of CHARGE syndrome.
abstract: BACKGROUND
  The phenotypic variability of patients with syndromes presenting with dysmorphism makes clinical diagnosis difficult, leading to an exhaustive genetic study to determine the underlying mechanism so that a proper diagnosis could be established.
  
  
  OBJECTIVE
  To genetically characterize siblings, the older sister diagnosed with Albright hereditary osteodystrophy and the younger one with CHARGE syndrome.
  
  
  METHODS
  Clinical case report.
  
  
  METHODS
  Clinical, biochemical, and radiological studies were performed on the family. In addition, molecular genetic studies including sequencing of GNAS, typing of microsatellites on 2q and 21q, and multiplex ligation-dependent probe amplification of subtelomeric regions were performed, as well as confirmatory fluorescent in situ hybridization analysis.
  
  
  RESULTS
  The genetic analysis revealed that both sisters presented a 2q37 deletion due to the maternal unbalanced segregation of a 2;21 translocation.
  
  
  CONCLUSIONS
  This is the first report of a 2q37 deletion where differential diagnosis of CHARGE syndrome is needed due to the appearance of choanal atresia.
authors.affiliation: Endocrinology and Diabetes Research Group, Molecular Genetics Lab, Hospital de Cruces, Cruces-Barakaldo E48903, Bizkaia, Basque Country, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernández-Rebollo
authors.forename: Olga
authors.initials: O
authors.lastname: Pérez
authors.forename: Cristina
authors.initials: C
authors.lastname: Martinez-Bouzas
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Cotarelo-Pérez
authors.forename: Intza
authors.initials: I
authors.lastname: Garin
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Ruibal
authors.forename: Gustavo
authors.initials: G
authors.lastname: Pérez-Nanclares
authors.forename: Luis
authors.initials: L
authors.lastname: Castaño
authors.forename: Guiomar Pérez
authors.initials: GP
authors.lastname: de Nanclares