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Updated: May 24, 2025
FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Routine detection of consanguinity through preimplantation genetic testing in human embryos
Catherine Kratka1, Jia Xu1, Jennifer Eccles1
1Genomic Prediction Inc., North Brunswick Township, New Jersey, USA.
Research Question:
Can a single-nucleotide polymorphism array-based preimplantation genetic testing (PGT) platform routinely detect consanguinity in preimplantation embryos?
Design:
A validation set consisting of 29 clinical PGT cases (five cases with confirmed consanguinity [positive control cases] and 24 randomly selected non-consanguineous cases [negative control cases]) was used to define a genetic threshold for the routine detection of consanguinity. PLINK software was used to identify all regions of homozygosity (ROH) greater than 5 Mb on each autosome. The percentage of ROH was then calculated and compared between the positive and negative control cases to determine a threshold. Next, the threshold was used to create a specific criterion that was applied to 6,380 clinical PGT cases (27,378 embryos in total) to calculate the prevalence of consanguineous cases within a single PGT laboratory.
Results:
The selected criterion defined cases as consanguineous when they contained two or more embryos with ROH percentages of 0.5% or more. Positive and negative control cases from the validation set fulfilled and failed this criterion, respectively. Of the 6380 cases evaluated, 0.45% (29) were defined as consanguineous.
Conclusions:
This study describes a PGT platform that can routinely screen for parental consanguinity by evaluating regions of homozygosity in IVF-derived embryos during routine genetic testing. Consanguinity can be detected without prior knowledge of a parental relationship. This can help to improve the utility of PGT and identify embryos at increased risk of recessive disease associated with consanguinity.
