What's already known about this topic?

  • Use of microarray for prenatal diagnosis increases the detection of pathogenic chromosomal rearrangements.
  • CPM is a well-established phenomenon occurring in 1–2% of CVS.

What does this study add?

  • CPM can occur for submicroscopic copy number changes detected by array CGH in DNA from uncultured CVS. In order to minimise the risk of false-positive results in these cases, detected copy number changes should be confirmed in a different source of material, such as cultured cells.