Karyomapping offers new way of detecting genetic conditions in IVF embryos

New research at the University of Kent has identified karyomapping as a viable and cost-effective method of detecting a wide range of genetic diseases in IVF embryos. The current method, which involves the use of preimplantation genetic diagnosis (PGD) for monogenic disorders (resulting from a single defective gene) has long been recognized as expensive and time-consuming and requires the tailoring of a specific test for each couple and/or disorder.

The new research, led by Darren Griffin, PhD, in collaboration with researchers at Illumina, Inc., Cambridge, showed that karyomapping could be used, simultaneously, as a new approach to PGD for monogenic disorders with the potential for the detection of chromosomal disorders. The research is described in a paper recently published in the Journal of Assisted Reproduction and Genetics.

The paper also describes how in one clinical case study, a male partner was affected with Marfan syndrome, an autosomal dominant disease affecting the connective tissue which can lead to heart (aorta) and/or visual (retina) problems. Single cells from IVF embryos were biopsied and analyzed using standard PGD approaches including minisequencing for the Marfan mutation and analysis of three informative linked markers. Karyomapping was used to confirm the diagnosis utilizing a rapid 24-hour protocol, enabling the researchers to perform karyomapping in a clinically applicable setting.

In a second clinical study, published earlier in 2014, karyomapping was used to confirm a PGD case detecting both chromosomal count (euploidy/aneuploidy) as well as a monogenic disorder (Smith-Lemli-Opitz [SLO] syndrome) simultaneously. In this study, the family underwent PGD with simultaneous diagnosis of both SLO status and chromosome constitution using standard approaches. Again, the diagnosis was confirmed simultaneously by karyomapping. Both clinical cases led to the birth of a healthy child, unaffected by Marfan syndrome and SLO respectively.