Joy Delhanty

Joy Delhanty

Professor Joy Delhanty is one of pioneers of PGD and world expert in the use of FISH (fluorescence in situ hybridisation) to detect chromosome anomalies in human embryos. 

Summary of Expertise

Joy Delhanty is an expert on cytogenetic (chromosomal) aspects of preimplantation development in humans and on the diagnosis of chromosomal disorders in the preimplantation embryo and the author of over 150 peer reviewed publications in Human Genetics. The results of all preimplantation diagnoses (PGD) on embryos for both single gene and chromosomal defects are authorised by Professor Delhanty.

Clinical Activity

A key role is Scientific Director (and co-founder) of the UCL Centre for Preimplantation Genetic Diagnosis. Single gene and chromosomal disorders are diagnosed in the 3-day old embryo prior to implantation, avoiding the need for prenatal diagnosis and termination of an established pregnancy. Aneuploidy screening is carried out for couples with repetitive IVF failure or repeated miscarriage. The UCL Centre for PGD is one of the few in the UK that offers treatment for a wide range of disorders and is one of the sole providers of PGD for genes predisposing to familial cancers.

Research Role

Leader of the UCL Group investigating the origin of chromosomal anomalies during oogenesis and embryogenesis and their effect on embryo survival. The Group has pioneered the use of comparative genomic hybridization (CGH) in single cells to screen the whole chromosome set via DNA analysis and has achieved an international reputation by applying this approach to cells derived from embryos and oocytes.
This research has provided an explanation for the poor survival of the majority of human embryos created by IVF.

Teaching Role

Proposer of the highly successful Master’s Programme in Prenatal Genetics and Fetal Medicine. Provider of specialist lectures to Masters students at UCL and elsewhere; supervision of projects carried out by both Master’s and PhD students.

Management/Administrative Role

Overall responsibility for the management of the PGD service, including the diagnostic and financial aspects.

Notable discoveries

Discovery of the first human triploid embryo; first demonstration of inherited Down syndrome; first proof that Knudson’s two-hit hypothesis for cancer development applied to pre-cancerous colorectal polyps; first proof of extensive chromosomal mosaicism in human embryos & of gonadal mosaicism in couples with repeated trisomy 21 conceptions.


Admitted to the Royal College of Pathologists as a Fellow in 1995 and to the Royal College of Obstetricians and Gynaecologists as a Fellow ad eundum in 2002.

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