The Discovery of Unbalanced Translocations through Genome-Wide cfDNA Testing [32R]

    loading  Checking for direct PDF access through Ovid



The MaterniT® GENOME test reports on genome-wide copy number variations >7Mb, making it uniquely positioned to identify deletions and duplications, such as those in unbalanced translocations. Since late 2015, more than 28,000 MaterniT® GENOME samples have been ordered. Here we describe cases where unbalanced translocations have been discovered.


Maternal blood samples submitted for genome-wide cfDNA testing were subjected to DNA extraction, library preparation, and whole-genome massively parallel sequencing as described by Jensen et al. Sequencing data were analyzed using a novel algorithm as described by Lefkowitz et al.


A total of 28,760 samples were submitted to the clinical laboratory and 1,392 (4.8%) of these resulted positive. Among all positives, 49 were interpreted as possible translocation events between two chromosomes. Fetal confirmation was reported in 59% with an additional 37% likely concordant given family or clinical history, there were two cases (4%) lost to follow up and zero reported discordant cases. Prior knowledge of parental translocation existed for 29%, while 16% were identified as follow up to cfDNA testing. A minority of cases (6%) were de novo, with the remaining subset pending full parental assessment (51%). Totals will be updated prior to final publication.


Familial translocations not previously amenable to cfDNA screening may now benefit from early identification or added reassurance. New discovery of families at risk of carrying a translocation often helps explain past pregnancy complications, as well as clarify future reproductive risk. MaterniT® GENOME is a relevant screening tool for families with a known translocation or suggestive family history.

Related Topics

    loading  Loading Related Articles