Genomic microarrays in clinical diagnosis.
OBJECTIVE
Cytogenetic analysis has for a long time relied on chromosome banding by karyotyping for whole-genome analysis of structural and numerical chromosomal anomalies. Conceptual and technical developments in molecular cytogenetics are rapidly changing the way the human genome is being analyzed by enhancing the resolving power from the megabase to the kilobase level. This review describes the various genomic microarray approaches that have been developed for molecular cytogenetic purposes and their implementation in a routine clinical diagnostic setting.


RESULTS
Genomic microarray approaches such as array-based comparative genomic hybridization have recently been shown to identify causative submicroscopic copy number alterations in a significant proportion of patients with mental retardation. These alterations occur throughout the human genome and the majority of these alterations reported thus far are unique. Next to these causative alterations, a large number of inherited submicroscopic copy number variations without immediate clinical consequences have been detected by these methods.


CONCLUSIONS
Genome profiling by genomic microarrays is becoming an important diagnostic tool, either in addition to or replacing conventional chromosome banding, depending on the expected diagnostic yield and the costs involved.
Veltman
Joris A
JA
Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. j.veltman@antrg.umcn.nl
D002675:Child, Preschool; D002658:Developmental Disabilities / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*