Ewch i’r prif gynnwys
Samuel Chawner   BA (Hons), PhD, FHEA

Dr Samuel Chawner

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BA (Hons), PhD, FHEA

Cymrawd Sefydliad Ymchwil Feddygol, Is-adran Meddygaeth Seicolegol a Niwrowyddorau Clinigol

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Trosolwyg

I research the impact of genomics on eating disorders, child development, and mental health.

A class of rare genomic variants known as copy number variants (CNVs, deletions or duplications of a chromosomal region), have been implicated in neurodevelopmental and psychiatric conditions, including eating disorders. Although individually rare, neuropsychiatric CNVs are collectively common, estimated to be present in 10-15% of individuals with neurodevelopmental conditions, and 1 in 200 individuals in the general population.

My work aims to characterise the clinical profiles of neuropsychiatric CNVs and understand the mechanisms by which psychiatric conditions develop in these groups at high genetic vulnerability.

This work has important implications for the increasing number of patients receiving genetic diagnoses in clinical settings. It also has wider implications for identifying early signs of psychiatric conditions in the general population.

Public and stakeholder engagement is a key part of my work and I regularly engage with the media, charities, artists, clinicians, and policymakers to raise awareness of research into genomic conditions and mental health.

Cyhoeddiad

2024

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2015

Articles

Thesis

Websites

Ymchwil

Research Overview

My research focuses on children and adolescents with genetic conditions associated with neurodevelopmental and psychiatric conditions. I focus on a class of genetic conditions known as copy number variants (CNV, a deletion or duplication of a chromosomal region). Several CNVs have been implicated in intellectual disability, autism, ADHD, extreme BMI outcomes, disordered eating and schizophrenia. However, the pleiotropic effects of psychiatric CNVs across childhood and adolescence are not fully known. My work aims to characterise these genomic conditions beyond categorical diagnoses using a range of dimensional, developmental and cognitive measures. My work contributes to range of national and international collaborations and consortiums focused on rare genomic variants and psychiatry.

Development of eating disorders in children at high genomic risk

In my Medical Research Foundation Fellowship, I will focus 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. This project hopes to increase our knowledge of the development and early signs of eating disorders, and provide vital information to the families affected by these rare genetic conditions.

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. 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). Other outputs of the IMAGINE-ID study can be found here, 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 am 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., 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).

Bywgraffiad

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

In 2020 I started a Wellcome Trust ISSF Fellowship, working on a project called "Using genomics to understand the early developmental origins of psychiatric conditions", which involved working across 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 Medical Research Council 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) at Girton College, University of Cambridge.

Anrhydeddau a dyfarniadau

  • Gwobr Teithio Cynhadledd MQ (2018)
  • Cyflwyniad Llafar yn rownd derfynol Cyngres Geneteg Seiciatrig y Byd (2017)
  • Gwobr teithio cynhadledd Canolfan y Cyngor Ymchwil Feddygol ar gyfer Geneteg Niwroseiciatrig a Genomeg Cynllun Ymchwilwyr Cynnar (2017)
  • Gwobr teithio cynhadledd Guarantors of Brain (2017)
  • Hyrwyddwr Ymgysylltu â'r Cyhoedd, Canolfan y Cyngor Ymchwil Meddygol ar gyfer Geneteg a Genomeg Niwroseiciatrig (2016)
  • Gwobr deithio Max Appeal ar gyfer Cynhadledd Syndrom Dileu 22q11.2 (2016)
  • Gwobr teithio Sefydliad Ymchwil Iechyd Meddwl Niwrowyddoniaeth y DU (2016)
  • Poster Finalist ar gyfer Cyngres Geneteg Seiciatrig y Byd (2014)
  • Gwobr Marion Bidder ac Ysgoloriaeth John Bowyer Buckley, a ddyfarnwyd am berfformiad ym mlwyddyn olaf y brifysgol (2011, Coleg Girton, Prifysgol Caergrawnt)

Aelodaethau proffesiynol

  • Genes i Iechyd Meddwl Aelod o'r consortiwm
  • IMAGINE-ID (Anabledd Deallusol ac Iechyd Meddwl: Asesu Effaith Genomig ar Niwroddatblygiad) Astudiaeth Cyd-Ymchwilydd
  • 22q11.2 Aelod Consortiwm Rhyngwladol yr Ymennydd ac Ymddygiad
  • Cyd-ymchwilydd consortiwm MINDDS (Maximising Impact of research in NeuroDevelopmental Disorders)
  • Grŵp Trawsbleidiol Cynulliad Cymru ar gyflyrau prin, genetig a heb ddiagnosis
  • 22q11.2 Cymdeithas Aelod Sefydlu

Safleoedd academaidd blaenorol

  • 2021 - Cymrawd y Sefydliad Ymchwil Meddygol presennol
  • 2020 - 2021: Cymrawd ISSF Ymddiriedolaeth Wellcome
  • 2019 - 2020: Cyswllt Ymchwil, Consortiwm Genes i Iechyd Meddwl
  • 2015 - 2019: Astudiaeth Cyswllt Ymchwil, IMAGINE-ID

Pwyllgorau ac adolygu

  • Adolygydd ar gyfer y American Journal of Psychiatry, Molecular Psychiatry, Journal of Abnormal Psychology, Child Neuropsychology, Journal of Consulting and Clinical Psychology, Psychological Medicine, Ymchwil mewn Anableddau Datblygiadol ac Adroddiadau Achos BMC
  • Cadeirydd grŵp ffocws polisi Ymchwilydd Gyrfa Gynnar yn Academi Gwyddorau Meddygol "Yr ymennydd sy'n datblygu mewn iechyd a chlefyd" Gweithdy
  • Adolygydd grant ar gyfer Gwobr MQ Gwyddor Data
  • Aelod o bwyllgor adolygu Banc Biobanc Prifysgol Caerdydd