Alan H. Handyside

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Embryonal stem (ES) cell lines, established in culture from peri-implantation mouse blastocysts, can colonize both the somatic and germ-cell lineages of chimaeric mice following injection into host blastocysts. Recently, ES cells with multiple integrations of retroviral sequences have been used to introduce these sequences into the germ-line of chimaeric(More)
BACKGROUND Pregnancy rates in women of advanced maternal age undergoing in vitro fertilization (IVF) are disappointingly low. It has been suggested that the use of preimplantation genetic screening of cleavage-stage embryos for aneuploidies may improve the effectiveness of IVF in these women. METHODS We conducted a multicenter, randomized, double-blind,(More)
Over 200 recessive X chromosome-linked diseases, typically affecting only hemizygous males, have been identified. In many of these, prenatal diagnosis is possible by chorion villus sampling (CVS) or amniocentesis, followed by cytogenetic, biochemical or molecular analysis of the cells recovered from the conceptus. In others, the only alternative is to(More)
BACKGROUND Several randomized controlled trials have not shown a benefit from preimplantation genetic screening (PGS) biopsy of cleavage-stage embryos and assessment of up to 10 chromosomes for aneuploidy. Therefore, a proof-of-principle study was planned to determine the reliability of alternative form of PGS, i.e. PGS by polar body (PB) biopsy, with whole(More)
The development of 181 surplus human embryos, including both normally and abnormally fertilized, was observed from day 2 to day 5, 6 or 7 in vitro. 63/149 (42%) normally fertilized embryos reached the blastocyst stage on day 5 or 6. Total, trophectoderm (TE) and inner cell mass (ICM) cell numbers were analyzed by differential labelling of the nuclei with(More)
The use of genome wide single nucleotide polymorphism (SNP) arrays for high resolution molecular cytogenetic analysis using a combination of quantitative and genotype analysis is well established. This study demonstrates that by Mendelian analysis of the SNP genotypes of the parents and a sibling or other appropriate family member to establish phase, it is(More)
Molecular genetic analysis of isolated single cells and other minute DNA samples is limited because there is insufficient DNA to perform more than one independent PCR amplification. One solution to this problem is to first amplify the entire genome, thus providing enough DNA for numerous subsequent PCRs. In this study we have investigated four different(More)
Preimplantation genetic diagnosis (PGD) of single gene defects following assisted conception typically involves removal of single cells from preimplantation embryos and analysis using highly sensitive PCR amplification methods taking stringent precautions to prevent contamination from foreign or previously amplified DNA. Recently, whole genome amplification(More)
We have used multicolour fluorescent in situ hybridisation (FISH) with DNA probes for chromosomes X, Y and 1 to analyse spare untransferred cleavage-stage embryos after preimplantation diagnosis to avoid X-linked disease. In total, 93 morphologically normal embryos were available from seven patients (six of proven fertility) who had undergone fourteen in(More)
We have previously detected chromosome abnormalities in human embryos whilst identifying the sex for preimplantation diagnosis of X-linked disease. In this study we assess the incidence of these abnormalities, both for sex chromosomes and autosomes 1 and 17, using dual fluorescent in situ hybridization (FISH). Sixty-nine normally fertilized embryos of good(More)