[Diagnosis of cryptic chromosome aberrations].
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.
Ness
Gro Oddveig
GO
Senter for medisink genetikk og molekylaemedisin, Haukeland Universitetssykehus, Bergen. gro.ness@helse-bergen.no
Houge
Gunnar
G
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
D015342:DNA Probes; D005819:Genetic Markers