Joint research between the University of Kent's Professor Darren Griffin, London Bridge Fertility Centre and BlueGnome Ltd has addressed chromosomal imbalance in embryos, a condition that is currently the major cause of pregnancy loss in IVF.
Published by the Journal of Medical Genetics, the team's research involved screening 164 eggs for aneuploidy, or the condition of a cell containing an incorrect number of chromosomes. Consequently, they discovered that, contrary to the widely held belief that aneuploidy in human embryos arises from incorrect separation of whole chromosomes (termed non-disjunction) during formation of an egg, human aneuploidy is likely to be due to an alternative method that involves the premature splitting and separation of individual chromosomes into their two halves.
Professor Griffin, a specialist in genetics at the University's School of Biosciences, explained that the screening was enabled by BlueGnome's 24sure platform, a technique that assesses aneuploidy though thousands of individual measurements across all chromosomes. 'The quantification is sufficiently accurate to distinguish between the gain or loss of whole or half chromosomes,' he said. 'Therefore an assessment of which method leads to aneuploidy -- i.e. the gain or loss -- can be made.'
Professor Griffin also explained that 'the wisdom that non-disjunction is the primary mechanism leading to human aneuploidy should be reconsidered and further investigations will needed to look at the causes of these mechanistic errors in this vital area of embryo development.'
Nick Haan, CEO of BlueGnome, said: 'This paper illustrates the power of 24sure technology and the vital need to detect even imbalance of chromatids when screening eggs to check that they are suitable for IVF.'
- A. S. Gabriel, A. R. Thornhill, C. S. Ottolini, A. Gordon, A. P. C. Brown, J. Taylor, K. Bennett, A. Handyside, D. K. Griffin. Array comparative genomic hybridisation on first polar bodies suggests that non-disjunction is not the predominant mechanism leading to aneuploidy in humans. Journal of Medical Genetics, 2011; 48 (7): 433 DOI: 10.1136/jmg.2010.088070
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