title: [Diagnosis of cryptic chromosome aberrations].
abstract: BACKGROUND
  Cryptic chromosome aberrations, i.e. those that are not observed by routine chromosome analysis (G-banding), can cause a plethora of developmental abnormalities, usually at least a combination of various dysmorphic signs and mental retardation.
  
  
  METHODS
  We present the current molecular cytogenetic methods for detection of cryptic chromosome aberrations, with special emphasis on comparative genomic hybridisation (CGH), a DNA-based screening method.
  
  
  RESULTS
  Using comparative genomic hybridisation with high-resolution analysis, we were able to detect a chromosome aberration in 10 % of patients found to have normal karyotypes by standard chromosome analysis.
  
  
  CONCLUSIONS
  Though the sensitivity of comparative genomic hybridisation is still insufficient for finding a deletion in most of the well-known microdeletion syndromes, the diagnostic yield of genomic imbalances is better than for all other laboratory investigations except routine G-banding.
authors.affiliation: Senter for medisink genetikk og molekylaemedisin, Haukeland Universitetssykehus, Bergen. gro.ness@helse-bergen.no
authors.forename: Gro Oddveig
authors.initials: GO
authors.lastname: Ness
authors.forename: Gunnar
authors.initials: G
authors.lastname: Houge
mesh_terms: D002648:Child; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics; D015342:DNA Probes; D002658:Developmental Disabilities / Q000175:diagnosis / Q000235:genetics; D005819:Genetic Markers; D005820:Genetic Testing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics; D007621:Karyotyping; D009693:Nucleic Acid Hybridization
chemical_list: D015342:DNA Probes; D005819:Genetic Markers