Hilary Cass

Hilary Dawn Cass is a British paediatrician known as chair of the British Academy of Childhood Disability, for establishing the Rett Clinic for children with the Rett syndrome neurodevelopmental disorder, for developing palliative care for children, as well as for leading the Cass Review completed in 2024. In the 2024 Dissolution Honours, Cass was nominated for a life peerage as a crossbencher.

Cass is a former president of the Royal College of Paediatrics and Child Health, and a honorary physician in paediatric disability at the Evelina Hospital, part of Guy's and St Thomas' NHS Foundation Trust. Prior to Cass's appointment at the Evelina Hospital, she had been consultant at Great Ormond Street Hospital for 15 years. Her research and interests have included autistic spectrum disorders, cognitive impairment due to epilepsy, children with visual loss, and care of children with multiple disabilities.

Early life and education
Hilary Cass completed her early education at the City of London School for Girls. She studied at the Royal Free hospital medical school, graduating with a degree in medicine in 1982.

Career
Cass spent her early medical career in a general practice training scheme, during which she changed to paediatrics. From 1992 to 2018, she was a consultant in neurodisability at three tertiary centres in the UK. Her research and interests have included autistic spectrum disorders, cognitive impairment due to epilepsy, children with visual loss, and care of children with multiple disabilities, particularly where there are difficulties with feeding and communication. In this field she has higlighted that medical innovations have resulted in a greater survival rate of children with severe incurable diseases, with the result that there are a greater number of children with severe disabilities.

Rett syndrome
In 1992 Cass founded the Rett clinic, a national outpatient service for children with the neurodevelopmental disorder Rett syndrome, based at the Evelina Hospital, part of Guy's and St Thomas' NHS Foundation Trust. She later reported that self-injurious behaviour in Rett Syndrome had a prevalence of 73.8%.

Great Ormond Street Hospital
From 1994 to 2009 Cass was consultant in paediatric disability at Great Ormond Street Hospital (GOSH). There, she was appointed director of Postgraduate Medical Education and held the post of deputy medical director. During that 15-year period she also held some regional and national positions in medical education and policy development, including head of the London School of Paediatrics. At GOSH, she authored a book titled Snakes and Ladders, based on a programme she led that used role play to understand patient journeys in the NHS and to teach staff clinical governance skills. The book addresses communication between doctors and patients, and primary and secondary care. Other topics covered include informed consent, medical negligence, medical paternalism, randomised controlled trials, and unlicensed treatments.

In 2008 she published findings that did not support the opioid excess theory. She reported on a large study she led that found no difference in urinary opioid peptide levels between those with autism and control subjects, and concluded that "opioid peptides can neither serve as a biomedical marker for autism nor be employed to predict or monitor response to a casein- and gluten-free diet".

Cass left GOSH after raising concerns about patient safety at the hospital. The hospital denied that she quit over patient safety concerns.

Evelina Hospital
Cass joined the Evelina Hospital as consultant in 2009. There, she developed palliative care services for children.

Cass Review
In September 2020, Cass accepted an appointment to lead the independent Cass Review for the NHS into gender identity services for children and young people. The interim report of the Cass Review was published in March 2022. It said that the rise in referrals had led to the staff being overwhelmed, and recommended the creation of a network of regional hubs to provide care and support to young people. The report noted that the clinical approach used by the Gender Identity Development Service (GIDS) "has not been subjected to some of the usual control measures" typically applied with new treatments, and raised concerns about the lack of data collection by GIDS. The recommendations resulted in the closure of GIDS. The final report was published on 10 April 2024.

Cass said after the publication of the review that she had received ‘vile’ emails and that she was not travelling by public transport after receiving security advice. She also said that she would not participate in the forthcoming review of adult gender clinics.

In May 2024 she made her first US media interview, on WBUR-FM's On Point, whom she told "The evidence was disappointingly poor". According to the New York Times, she said that US doctors were ‘out of date’ on gender care.

Other roles
In 2012 Cass was appointed president of the Royal College of Paediatrics and Child Health for a three-year tenure. Between 2017 and 2020 she was chair of the British Academy of Childhood Disability. She is a trustee of Noah’s Ark Children’s Hospice, and was formerly chair of the charity Together for Short Lives.

Honours and awards
Cass was appointed an Officer of the Order of the British Empire (OBE) in the 2015 New Year Honours for services to child health. In the same year the Royal College of Nursing awarded her an honorary fellowship (FRCN), and the following year she received one from the Royal College of General Practitioners (FRCGP).

Peerage
In the 2024 Dissolution Honours, Cass was nominated for a life peerage as a Crossbencher.