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Determination of the genetic status of cleavage‐stage human embryos by microsatellite marker analysis following multiple displacement amplification
Author(s) -
Renwick Pamela J.,
Lewis Cathryn M.,
Abbs Stephen,
Ogilvie Caroline Mackie
Publication year - 2007
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.1638
Subject(s) - biology , aneuploidy , microsatellite , embryo , blastomere , genetics , genetic marker , microbiology and biotechnology , polymerase chain reaction , allele , genotype , gene duplication , chromosome , gene , embryogenesis
Objectives To analyse genotype information from cleavage‐stage human embryos and assess the chromosomal status and feasibility of performing aneuploidy screening by microsatellite analysis. Methods DNA from 49 blastomeres from eight cleavage‐stage human embryos was amplified using multiple displacement amplification, then tested for panels of 64 polymorphic microsatellite markers on seven different chromosomes, and for two non‐polymorphic sequences on the X and Y chromosomes. Results There was an overall allele drop out (ADO) rate of 28%. Novel alleles in single cells were seen in 0.3% of amplifications, interpreted as either somatic microsatellite mutation events or ‘slippage’ of the MDA ϕ 29 polymerase. Three‐allele results for a single marker in a single cell were found in 0.07% of amplifications, interpreted as ‘slippage’ of the MDA ϕ 29 polymerase. One apparent segmental duplication was found. Only one embryo with no normal cells was found, probably arising from the chaotic cleavage division following a triploid conception. Six embryos were mosaic, of which four had only one abnormal cell. Conclusions Abnormalities in human embryos may be present in only a single cell, leading to potentially false abnormal results at pre‐implantation genetic diagnosis. ADO associated with MDA reduces the efficacy of this approach for detection of aneuploidy. Statistical analysis showed that, for ADO of 28%, seven informative markers would be required to give 95% confidence of detecting trisomic embryos. Copyright © 2007 John Wiley & Sons, Ltd.