EGA Institute for Women's Health


Professor Joy Delhanty

7 October 2021

It is with great sadness that we announce the death of Professor Joy Delhanty on 1st October 2021.

Professor Joy Delhanty

Joy started in UCL as an undergraduate reading Zoology in 1956. To put it in context, that was the year it was proven that 46 was the normal number of chromosomes per cell for humans! Following her Bachelors degree Joy went on to a PhD under the supervision of Professor Lionel Penrose in UCL. 
In her early career Joy discovered the first human triploid embryo and the first example of chromosome translocation leading to familial Down syndrome. From 1975 onwards she began working on the genetics and cytogenetics of human cancer and in the mid 1980s she became involved in experimental studies towards the development of earlier prenatal diagnosis of chromosome anomalies from chorionic villus samples and then in collaboration with colleagues from the Institute of Obstetrics and Gynaecology at the Hammersmith Hospital, genetic diagnosis in preimplantation (IVF) embryos. The application of dual FISH, with X and Y specific probes for sexing preimplantation embryos led, in 1993, to the birth of the first baby correctly sexed by FISH before implantation. 

In October 1993 she became Director of the Clinical Cytogenetics Unit of UCLH.  In that year Joy, elected to transfer to the department of Obstetrics & Gynaecology, under Professor Charles Rodeck.  In 1997 Joy became Professor. Together with Joyce Harper, she established the UCL Centre for PGD. In 1995 her group was the first to progress to the detection of chromosomal imbalance by the use of FISH in embryos from high risk couples presenting with gonadal mosaicism or chromosomal translocations. Joy continued to carry out pioneering work in the field of PGD right up until 2015 when the Unit had to cease doing clinical work; in later years she became interested in chromosomes of human unfertilised oocytes. This led to a host of publications almost until the present day concerning chromosome anomalies in oocytes, in particular the extent of gonadal or germinal mosaicism. 

Joy became Emeritus Professor in 2003. In her long and distinguished career she has supervised 25 PhD students, been awarded 27 research grants, and she has published over 190 peer reviewed research papers. 

Joy was pretty much the epitome of a consummate scientist. Intelligent, inquisitive, observant and possessed of a passion and a dedication to her field that comes with true interest in a subject. She genuinely cared for the patients who would ultimately benefit from her work. She was a great teacher and mentor; she leaves a legacy of many successful scientists in institutions across the world who have had the good fortune of her guidance at various stages of their own journeys in genetics. As a person, she was quiet, modest and unassuming, mostly letting her work speak for her. She will be sorely missed by her many students, colleagues and associates over the decades. UCL is a poorer place without her.