Dr Samuel Chawner

(he/him)

BA (Hons), PhD, FHEA

Publication

• Date
• Type

Research

Research Overview

I am passionate about understanding the causes and development of child mental health using cutting-edge mental health data science and genetic methodologies. My work bridges mental health data science and lived experience, and includes the voices of public, clinical, and policy stakeholders to shape and drive meaningful impact.

My research spans:

✨ The aetiology and epidemiology of eating disorders

✨ Mental health in children with rare genetic conditions

My work aims to characterise the developmental pathways from genomic and enivronmental risk factors to psychiatric outcomes, enabling the identification of early signs of risk and potential targets for early intervention. My work contributes to range of national and international collaborations and consortia focused on rare genomic variants and psychiatry.

Charactersing the clinical heterogeneity and aetiology of Avoidant Restirictive Food Intake Disorder

In 2024, I received an 8 year Wellcome Trust Career Development Award to investigate the development of ARFID (Avoidant/Restrictive Food Intake Disorder). ARFID was introduced to the DSM-5 diagnostic classification system in 2013, and is a severe feeding and eating disorder marked by food avoidance and restricted intake, with a prevalence of 1-2%, and serious consequences which can include malnutrition, psychosocial distress and in-patient ward tube feeding. ARFID is heterogeneous in clinical presentation, encompassing symptoms such as diminished appetite, sensory-based food aversion, and fear of adverse consequences associated with eating. This heterogeneity has raised important and related questions about the conceptualisation of ARFID. 

1. Should ARFID be conceptualised as either a neurodevelopmental condition, an anxiety disorder, a consequence of metabolic imbalance or a combination of these?
2. Does ARFID consist of a collection of aetiologically distinct subtypes which will require different treatment approaches?

To address this, I will use large-scale cohorts to:

1. Characterise the heterogeneity of ARFID
2. Derive data-driven subtypes
3. Investigate aetiology, and whether subtypes can be aetiologically distinguished

With ARFID research in its infancy, now is the time to answer these fundamental questions to inform future aetiological research and intervention approaches. I will work with individuals living with ARFID, services, and the charity Beat, throughout the fellowship to co-produce evidence-based resources, and influence service development.

Development of eating disorders in children at high genomic risk

In my Medical Research Foundation Fellowship, I focused on two rare genetic conditions that are linked with extreme differences in body weight and abnormal eating behaviour. These genetic conditions are caused by DNA being deleted or duplicated on one of the chromosomes, known as ‘16p11.2 deletion syndrome’ and ‘16p11.2 duplication syndrome’. Individuals with 16p11.2 deletion syndrome are at high risk of obesity and eating binges, whereas patients with 16p11.2 duplication syndrome tend to be very underweight and at higher risk of restrictive eating disorders. 

Genomics and early child development

In my Wellcome Trust ISSF3 Fellowship I combined psychiatric genetics and developmental psychology to investigate the early developmental origins of psychiatric risk (Chawner et al, 2023). I investigated the early behavioural profile of young children with psychiatric risk genetic conditions, by assessing key aspects of early development including language, communication, social development, motor control, and a range of brain functions including understanding emotions, planning ability, memory and sensory abilities.

Genotype-phenotype relationships in autism

This project investigated the extent to whether different genetic conditions lead to different subtypes of autism. The findings published in the American Journal of Psychiatry found that genetic conditions had diverse by high overlapping effects on autism symptoms (Chawner et al, 2021). This was an exciting project that combined data on 16p11.2 Deletion, 16p11.2 Duplication, 22q11.2 Deletion, and 22q11.2 Duplication syndromes from 8 international research sites across Europe and the US.

Intellectual Disability and Mental Health: Assessing Genomic Impact on Neurodevelopment (IMAGINE-ID) study

The IMAGINE-ID study involves a collaboration between Cardiff, Cambridge University and University College London. The project aims to increase understanding of the links between intellectual disability and chromosomal disorders, with the ultimate goal of improving insights into the clinical profiles of chromosomal disorders in order to inform prognosis and management. I worked as a Research Associate and coordinated the deep phenotyping component of the IMAGINE-ID study which I published in Lancet Psychiatry (Chawner et al,  2019). I am Co-Investigator on a recently funded longitudinal follow-up of the IMAGINE-ID cohort to investigate the development of mental health across adolescence.

Maximising Impact of research in NeuroDevelopmental DisorderS (MINDDS)

The MINDDS project brings together a pan-European network of clinical scientists, preclinical researchers and patient representatives to advance studies of individuals with neurodevelopmental conditions caused by CNVs and to ultimately improve care for these patients. I was a Co-Investigator of the network, and led a project scoping out the CNV landscape in Europe (Chawner & Mihaljevic et al, 2020).I was also involved in running a training school in clinical phenotyping for clinicians an researchers in Skopje, Macedonia.

Genes to Mental Health consortium

I am member of the Genes to Mental Health Consortium, which is structured around four projects that will study the behavioral and cognitive symptoms in individuals with rare genetic variants that confer high risk for neurodevelopmental psychiatric conditions. Participants will be identified in hospital clinics as well as in the general population across three continents.

Longitudinal development of 22q11.2 Deletion Syndrome

As part of my PhD I conducted a longitudinal study of adolescents with 22q11.2 Deletion Syndrome, who have high genetic vulnerability to developing psychosis.  I investigated how cognition changed over this vulnerable period (Chawner et al, 2017) and identified predictors of psychotic experiences emergence in 22q11.2 Deletion Syndrome (Chawner et al, 2019). My PhD data contributed to the 22q11.2 International Brain & Behaviour Consortium, which has led to a range of collaborative papers.

Funding and Grants

• Chawner, S.J.R.A., Charactersing the clinical heterogeneity and aetiology of Avoidant Restirictive Food Intake Disorder. Wellcome Trust Career Development Award (2024).
• Chawner, S.J.R.A., Sønderby, I.E., Andreassen, O.A., Fox, J., Bulik, C., Owen, M.J., van den Bree, M.B.M. The relationship between the 16p11.2 locus and eating disorders: novel insights from rare genetic conditions. Medical Research Foundation Eating Disorder & Self Harm Fellowship (2021).
• Chawner, S.J.R.A. Using genomics to understand the early developmental origins of psychiatric conditions. Wellcome Trust ISSF3 Fellowship Award (2020).
• Skuse, D., Hall, J., van den Bree, M.B.M., Chawner, S.J.R.A., Owen, M.J., Holman, P., Raymond, F.L., Mandy, W., Denaxas, S. IMAGINE-2: Stratifying Genomic Causes of Intellectual Disability by Mental Health Outcomes in Childhood and Adolescence. Medical Research Council Programme Grant (2020).
• Chawner, S.J.R.A., Hopkins, C., Phenotypica. Embracing complexity - humanising mental health and genetics research through creative multi-stakeholder engagement. Wellcome Trust ISSF3 Public Engagement Proof-of-Concept Award (2020).
• Chawner, S.J.R.A. The sleep profile of children with autism associated with a genetic condition. Cardiff Undergraduate Research Opportunities Programme, summer studentship scheme (postponed due to COVID-19).
• van den Bree, M.B.M., Raymond, F.L., Escott-Price, V., Chawner, S.J.R.A. Pilot study to develop an instrument to capture broad-ranging neurodevelopmental problems in children with a genetic diagnosis of intellectual disability. Baily Thomas Charitable Fund (2019).
• Chawner, S.J.R.A. The early development of toddlers at genomic risk of schizophrenia. Cardiff Undergraduate Research Opportunities Programme, summer studentship scheme (2019).
• Chawner, S.J.R.A. The impact of genomics on childhood development. Cardiff Undergraduate Research Opportunities Programme, summer studentship scheme, PI, (2018).
• Chawner, S.J.R.A., Hay, D., Erichsen, J., Owen, M.J., Hall, J., van den Bree, M.B.M. The developmental origins of psychiatric disorder: an assessment of early childhood in 22q11.2. Deletion Syndrome. Neuroscience Mental Health Research Institute, seedcorn award, (2017).
• Chawner, S.J.R.A., Hay, D., Erichsen, J., Owen, M.J., van den Bree, M.B.M. The developmental origins of psychiatric disorder: an assessment of early childhood in 22q11.2. Deletion Syndrome. Medical Research Council Neuropsychiatric Genetics and Genomics, seedcorn award, (2017).
• European Cooperation in Science & Technology, networking grant, MINDDS (Maximising Impact of research in NeuroDevelopmental DisorderS), Co-Investigator (2017).
• Chawner, S.J.R.A. The Development of Children at High Genetic Risk of Schizophrenia. Cardiff University Research Society, summer studentship scheme (2017).
• Chawner, S.J.R.A. The development of children at genomic risk of psychiatric disorder. Cardiff Undergraduate Research Opportunities Programme, summer studentship scheme (2016).
• Chawner, S.J.R.A. The development of children at genomic risk of psychiatric disorder. Cardiff University Research Society, summer studentship scheme (2016).
• Chawner, S.J.R.A. Medical Research Council, supplement award, statistical training in longitudinal methods (2014).
• Chawner, S.J.R.A. Medical Research Council PhD Studentship (2011).

Biography

In 2024, I started a prestigious 8 year Wellcome Trust Career Development Award investigating the epidemiology and aetiology of the understudied eating disorder, Avoidant Restrictive Food Intake Disorder (ARFID).

2021-2024 I held a Medical Research Foundation Mid-career Fellowship which focuses on the development of eating disorders in children & adolescents at high genetic vulnerability (as conferred by rare variation at the 16p11.2 locus).

2020-2021 I held a Wellcome Trust ISSF Fellowship which was titled "Using genomics to understand the early developmental origins of psychiatric conditions", which involved the Cardiff University Centre for Human Developmental Science, and the Medical Research Council Centre for Neuropsychiatric Genetics and Genomics.

My previous postdoctoral work, as part of the IMAGINE-ID and G2MH studies, investigated genotype and phenotype relationships across a range of neurodevelopmental risk genomic conditions. I continue to contribute to a range of national and international research programmes of individuals with rare chromosomal Copy Number Variants (CNVs) associated with neuropsychiatric risk.

In 2016 I completed a PhD in Medicine at the Centre for Neuropsychiatric Genetics and Genomics. The title of my thesis was "Longitudinal follow-up of 22q11.2 Deletion Syndrome: a study of individuals at high risk of schizophrenia".

Prior to my PhD, I obtained a First Class BA honours in Psychology (Natural Sciences Tripos) with prizes at Girton College, University of Cambridge.

Honours and awards

• Health and Care Research Wales Rising Star Award (2024)
• Cambridge University Q100 list of trailblazing LGBTQ+ alumni (2024)
• Spectrum News highly cited list, featured in "Trends in autism research 2021"               
• American Journal of Psychiatry highest altmetric score of the month award (2021)
• MQ conference travel award (2018)
• Oral Presentation Finalist for the World Congress of Psychiatric Genetics (2017)
• Medical Research Council Centre for Neuropsychiatric Genetics and Genomics Early Researcher Scheme conference travel award (2017)
• Guarantors of Brain conference travel award (2017)
• Public Engagement Champion, Medical Research Council Centre for Neuropsychiatric Genetics and Genomics (2016)
• Max Appeal travel award for 22q11.2 Deletion Syndrome Conference (2016)
• Neuroscience Mental Health Research Institute UK travel award (2016)
• Poster Presentation Finalist for the World Congress of Psychiatric Genetics (2014)
• The Marion Bidder Prize and the John Bowyer Buckley Scholarship, awarded for performance in final year of university (2011, Girton College, Cambridge University)

Professional memberships

• Psychiatric Genetics Consortium - Eating Disorder working group member
• Genes to Mental Health Consortium member
• IMAGINE-ID (Intellectual Disability and Mental Health: Assessing Genomic Impact on Neurodevelopment) study Co-Investigator
• 22q11.2 International Brain & Behaviour Consortium member
• MINDDS (Maximising Impact of research in NeuroDevelopmental DisorderS) consortium Co-Investigator
• Welsh Assembly Cross Party Group on Rare, Genetic and Undiagnosed Conditions
• 22q11.2 Society Founding Member

Academic positions

• 2024 onwards Senior Research Fellow (Wellcome Trust funded)
• 2021 - 2024: Medical Research Foundation Fellow
• 2020 - 2021: Wellcome Trust ISSF Fellow
• 2019 - 2020: Research Associate, Genes to Mental Health Consortium
• 2015 - 2019: Research Associate, IMAGINE-ID study

Committees and reviewing

• Reviewer for leading journals including American Journal of Psychiatry, Biological Psychiatry, Molecular Psychiatry, & Psychological Medicine
• Grant Reviewer for the Medical Research Council, Wellcome Trust, and the MQ Data Science Award
• Chair of Early Career Researcher policy focus group at Academy of Medical Sciences “The developing brain in health and disease” Workshop
• Cardiff University Biobank review committee member