Array-CGH fine mapping of minor and cryptic HR-CGH detected genomic imbalances in 80 out of 590 patients with abnormal development

Eur J Hum Genet. 2008 Nov;16(11):1318-28. doi: 10.1038/ejhg.2008.78. Epub 2008 May 7.


During a 6-year period, 590 patients suspected of having a minor or cryptic genomic imbalance as the cause of mental retardation with dysmorphic signs +/- malformations have been investigated with high-resolution comparative genomic hybridisation (HR-CGH) in our diagnostic laboratory. Thirty-six patients had a small chromosomal aberration detected by routine karyotyping, and 554 patients had a normal G-banded karyotype. In the latter group, a genomic imbalance was detected by HR-CGH in 40 patients (7.2%): 29 deletions, 3 duplications, 4 unbalanced translocations, and 4 occult trisomy mosaicisms. When microarray-based comparative genomic hybridisation (array-CGH) became available, all HR-CGH-positive samples were also investigated by 1 Mb resolution array-CGH for more precise mapping. From the 514 patients with normal HR-CGH findings, a subset of 20 patients with particularly high suspicion of having a chromosomal imbalance was selected for array-CGH. In four of them (20%), an imbalance was detected: three deletions and one duplication. Of note, 73 out of the 80 array-CGH mapped patients had a de novo chromosomal rearrangement (91%). Taken together, this work provides phenotype-genotype information on 80 patients with minor and cryptic chromosomal imbalances.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Chromosome Mapping
  • Chromosomes, Human / genetics*
  • Female
  • Follow-Up Studies
  • Genomic Instability*
  • Humans
  • Infant
  • Intellectual Disability / genetics*
  • Male
  • Middle Aged
  • Mutation*
  • Nucleic Acid Hybridization / methods