Earlier- and later-diagnosed autism may be genetically different

Publicly released:
Australia; International; NSW; VIC; QLD; SA
Photo by Alireza Attari on Unsplash
Photo by Alireza Attari on Unsplash

People with autism tend to have different developmental and genetic profiles depending on whether they were diagnosed with autism in early childhood or from late childhood onwards, according to Australian and international research. The study found the genetic differences between these groups were similar to differences expected between distinct psychiatric conditions, rather than within the same one.  One of these groups tends to have an earlier autism diagnosis and lower social and communication abilities in early childhood, but with only a moderate genetic link to ADHD and mental-health conditions, while the other group tends to have a later autism diagnosis and stronger genetic links with ADHD and mental-health conditions, the authors say.

Media release

From: Springer Nature

Genetics: Genetically different forms of autism spectrum disorder (N&V)

The age that autism is diagnosed may partly reflect underlying biological and developmental differences among individuals with autism, finds a study published in Nature. The research identifies distinct developmental and genetic patterns between those diagnosed in early childhood and those diagnosed later, typically from late childhood onwards, with implications for understanding co-occurring mental health conditions.

Autism is an umbrella term that covers many differences within the neurodevelopmental condition, but clear ways to distinguish these differences remain limited. Although social and demographic factors have been linked to age at diagnosis, the role of genetics has not been well studied. As more people are getting diagnosed later in life, often alongside conditions such as anxiety, attention deficit–hyperactivity disorder (ADHD) and depression, understanding these differences is increasingly important.

Using behavioural data from 4 birth cohorts, ranging from 89 to 188 individuals, and genetic data from two large studies, Varun Warrier and colleagues found that common genetic variants explain around 11% of the variation in age at autism diagnosis. They identified two groups with different behavioural trajectories with separate genetic profiles: one where social and communication difficulties, such as anxiety, hyperactivity and difficulties with social interaction, appear early but remain stable, and another where such difficulties increase during adolescence. Those, on average, diagnosed from late childhood onwards were also more likely to experience mental health conditions such as depression compared with those who received a diagnosis earlier in childhood. The authors found that the genetic differences between these different groups were comparable to those between psychiatric conditions, rather than within one.

The findings suggest that autism diagnosed at different ages may reflect distinct developmental pathways and provides a clearer way to understand variation within the diverse condition. The findings may help guide future research and support strategies. The authors conclude that further research on diverse genetic ancestries is needed.

Attachments

Note: Not all attachments are visible to the general public. Research URLs will go live after the embargo ends.

Research Springer Nature, Web page Please link to the article in online versions of your report (the URL will go live after the embargo ends).
Journal/
conference:
Nature
Research:Paper
Organisation/s: The University of New South Wales, QIMR Berghofer, The University of Melbourne, The University of Sydney, Queensland University of Technology (QUT), The University of Adelaide, University of the Sunshine Coast, University of Cambridge, UK
Funder: This research was supported by funding from the Simons Foundation for Autism Research Initiative, the Wellcome Trust (214322\Z\18\Z and 226392/Z/22/Z), Horizon-Europe R2D2-MH (grant agreement 101057385) and UKRI (10063472). For the purpose of open access, we have applied a CC BY public copyright licence to any author-accepted manuscript version arising from this submission. S.B.-C. also received funding from the Autism Centre of Excellence at Cambridge, the Templeton World Charitable Fund, the MRC and the National Institute for Health Research Cambridge Biomedical Research Centre. The research was supported by the National Institute for Health Research Applied Research Collaboration East of England. Any views expressed are those of the author(s) and not necessarily those of the funder. Some of the results leading to this publication have received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement 777394 for the project AIMS-2-TRIALS. This joint undertaking receives support from the European Union’s Horizon 2020 research and innovation program and the EFPIA and Autism Speaks, Autistica and the SFARI. The iPSYCH team was supported by grants from the Lundbeck Foundation (R102-A9118, R155-2014-1724 and R248-2017-2003), the NIMH (1R01MH124851-01 to A.D.B.) and the European Union’s Horizon Europe program (R2D2-MH; grant agreement 101057385 to A.D.B.). The Danish National Biobank resource was supported by the Novo Nordisk Foundation. High-performance computer capacity for handling and statistical analysis of iPSYCH data on the GenomeDK HPC facility was provided by the Center for Genomics and Personalized Medicine and the Centre for Integrative Sequencing, iSEQ, Aarhus University, Denmark (grant to A.D.B.). The UK Medical Research Council and Wellcome (grant 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. This publication is the work of the authors and the authors will serve as guarantors for the contents of this paper. A comprehensive list of grants funding is available on the ALSPAC website (http://www.bristol. ac.uk/alspac/external/documents/grant-acknowledgements.pdf). R2D2-MH has been funded by Horizon Europe (grant agreement 101057385), by UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee (grant 10039383) and by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract 22.00277. A.H. and L.E.H. were supported by the Norwegian Research Council (336085) and the Norwegian Health Authority (2020022, #2022029 and #2022083). E.V. and B.S.P. are funded by the Max Planck Society. We thank the Centre for Longitudinal Studies (CLS), UCL Social Research Institute, for the use of these data and the UK Data Service for making them available. However, neither CLS nor the UK Data Service bear any responsibility for the analysis or interpretation of these data. This paper uses unit record data from Growing Up in Australia, the Longitudinal Study of Australian Children. The study is conducted in partnership between the Department of Social Services (DSS), the Australian Institute of Family Studies (AIFS) and the Australian Bureau of Statistics (ABS). The findings and views reported in this paper are those of the author and should not be attributed to DSS, AIFS or the ABS. Growing Up in Ireland (GUI) was funded by the Government of Ireland through the Department of Children, Equality, Disability, Integration and Youth (DCEDIY) and the Central Statistics Office (CSO). Results in this report are based on analysis of data from research microdata files provided by the Central Statistics Office (CSO). Neither the CSO nor the DCEDIY take any responsibility for the views expressed or the outputs generated from these analyses. We thank all the families who took part in this study, the midwives for their help in recruiting them and the ALSPAC team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists and nurses. This study includes data from the Norwegian Mother, Father and Child Cohort Study, conducted by the Norwegian Institute of Public Health. We thank all the participating families, and A. Kwong, T. Ford, W. Mandy and A. Grotzinger for discussions.
Media Contact/s
Contact details are only visible to registered journalists.