Identification of non-recurrent submicroscopic genome imbalances: the advantage of genome-wide microarrays over targeted approaches

Eur J Hum Genet. 2008 Mar;16(3):395-400. doi: 10.1038/sj.ejhg.5201975. Epub 2008 Jan 9.

Abstract

Genome-wide analysis of DNA copy-number changes using microarray-based technologies has enabled the detection of de novo cryptic chromosome imbalances in approximately 10% of individuals with mental retardation. So far, the majority of these submicroscopic microdeletions/duplications appear to be unique, hampering clinical interpretation and genetic counselling. We hypothesised that the genomic regions involved in these de novo submicroscopic aberrations would be candidates for recurrent copy-number changes in individuals with mental retardation. To test this hypothesis, we used multiplex ligation-dependent probe amplification (MLPA) to screen for copy number changes at eight genomic candidate regions in a European cohort of 710 individuals with idiopathic mental retardation. By doing so, we failed to detect additional submicroscopic rearrangements, indicating that the anomalies tested are non-recurrent in this cohort of patients. The break points flanking the candidate regions did not contain low copy repeats and/or sequence similarities, thus providing an explanation for its non-recurrent nature. On the basis of these data, we propose that the use of genome-wide microarrays is indicated when testing for copy-number changes in individuals with idiopathic mental retardation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Chromosome Mapping
  • Cohort Studies
  • DNA Primers
  • Genome, Human*
  • Humans
  • Intellectual Disability / genetics
  • Ligase Chain Reaction
  • Oligonucleotide Array Sequence Analysis*

Substances

  • DNA Primers