Tag: autism spectrum disorder

Categories : Genetics Mental HealthTags :

Major Study Identifies Four Biologically Distinct Subtypes of Autism

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Researchers at Princeton University and the Simons Foundation have identified four clinically and biologically distinct subtypes of autism, marking a transformative step in understanding the condition’s genetic underpinnings and potential for personalised care.

Analysing data from over 5000 children in SPARK, an autism cohort study funded by the Simons Foundation, the researchers used a computational model to group individuals based on their combinations of traits. The team used a “person-centred” approach that considered a broad range of over 230 traits in each individual, from social interactions to repetitive behaviours to developmental milestones, rather than searching for genetic links to single traits. 

This approach enabled the discovery of clinically relevant autism subtypes, which the researchers linked to distinct genetic profiles and developmental trajectories, offering new insights into the biology underlying autism. Their results were published July 9 in Nature Genetics.

“Understanding the genetics of autism is essential for revealing the biological mechanisms that contribute to the condition, enabling earlier and more accurate diagnosis, and guiding personalised care,” said senior study author Olga Troyanskaya, director of Princeton Precision Health, professor of computer science and the Lewis-Sigler Institute for Integrative Genomics at Princeton, and deputy director for genomics at the Center for Computational Biology of the Simons Foundation’s Flatiron Institute.

The study defines four subtypes of autism: Social and Behavioural Challenges, Mixed ASD with Developmental Delay, Moderate Challenges, and Broadly Affected. Each subtype exhibits distinct developmental, medical, behavioural and psychiatric traits, and importantly, different patterns of genetic variation. 

  • Individuals in the Social and Behavioural Challenges group show core autism traits, including social challenges and repetitive behaviours, but generally reach developmental milestones at a pace similar to children without autism.  They also often experience co-occurring conditions like ADHD, anxiety, depression or obsessive-compulsive disorder alongside autism. One of the larger groups, this constitutes around 37% of the participants in the study.
  • The Mixed ASD with Developmental Delay group tends to reach developmental milestones, such as walking and talking, later than children without autism, but usually does not show signs of anxiety, depression or disruptive behaviours. “Mixed” refers to differences within this group with respect to repetitive behaviours and social challenges. This group represents approximately 19% of the participants.
  • Individuals with Moderate Challenges show core autism-related behaviours, but less strongly than those in the other groups, and usually reach developmental milestones on a similar track to those without autism. They generally do not experience co-occurring psychiatric conditions. Roughly 34% of participants fall into this category.
  • The Broadly Affected group faces more extreme and wide-ranging challenges, including developmental delays, social and communication difficulties, repetitive behaviours and co-occurring psychiatric conditions like anxiety, depression and mood dysregulation. This is the smallest group, accounting for around 10% of the participants.

“These findings are powerful because the classes represent different clinical presentations and outcomes, and critically we were able to connect them to distinct underlying biology,” said Aviya Litman, a PhD student at Princeton. 

Distinct genetics behind the subtypes

For decades, autism researchers and clinicians have been seeking robust definitions of autism subtypes to aid in diagnosis and care. Autism is known to be highly heritable, with many implicated genes. 

“While genetic testing is already part of the standard of care for people diagnosed with autism, thus far, this testing reveals variants that explain the autism of only about 20% of patients,” said co-author Jennifer Foss-Feig, a clinical psychologist at the Icahn School of Medicine at Mount Sinai and vice president and senior scientific officer at the Simons Foundation Autism Research Initiative (SFARI). This study takes an approach that differs from classic gene discovery efforts by identifying robust autism subtypes that are linked to distinct types of genetic mutations and affected biological pathways.

For example, children in the Broadly Affected group showed the highest proportion of damaging de novo mutations, while only the Mixed ASD with Developmental Delay group was more likely to carry rare inherited genetic variants. While children in both of these subtypes share some important traits like developmental delays and intellectual disability, these genetic differences suggest distinct mechanisms behind superficially similar clinical presentations. 

“These findings point to specific hypotheses linking various pathways to different presentations of autism,” said Litman, referring to differences in biology between children with different autism subtypes.

Moreover, the researchers identified divergent biological processes affected in each subtype. “What we’re seeing is not just one biological story of autism, but multiple distinct narratives,” said Natalie Sauerwald, associate research scientist at the Flatiron Institute and co-lead author. “This helps explain why past genetic studies often fell short – it was like trying to solve a jigsaw puzzle without realising we were actually looking at multiple different puzzles mixed together. We couldn’t see the full picture, the genetic patterns, until we first separated individuals into subtypes.”

Autism biology unfolds on different timelines

The team also found that autism subtypes differ in the timing of genetic disruptions’ effects on brain development. Genes switch on and off at specific times, guiding different stages of development. While much of the genetic impact of autism was thought to occur before birth, in the Social and Behavioural Challenges subtype – which typically has substantial social and psychiatric challenges, no developmental delays, and a later diagnosis – mutations were found in genes that become active later in childhood. This suggests that, for these children, the biological mechanisms of autism may emerge after birth, aligning with their later clinical presentation.

“By integrating genetic and clinical data at scale, we can now begin to map the trajectory of autism from biological mechanisms to clinical presentation,” said co-author Chandra Theesfeld, senior academic research manager at the Lewis-Sigler Institute and Princeton Precision Health.

A paradigm shift for autism research

This study builds on more than a decade of autism genomics research led by Troyanskaya and collaborators. It is enabled by the close integration of interdisciplinary expertise in genomics, clinical psychology, molecular biology, computer science and modelling, and computational biology.

“The Princeton Precision Health initiative uses artificial intelligence and computational modelling to integrate across biological and clinical data,” said Jennifer Rexford, Princeton University provost and Gordon Y.S. Wu Professor in Engineering. “This initiative could not exist without the University’s charitable endowment. Our investments allow experts to collaborate across a range of disciplines to conduct transformative research that improves human health, including the potential for major advances in the diagnosis and treatment of autism made possible in this exciting project.” 

“It’s a whole new paradigm, to provide these groups as a starting point for investigating the genetics of autism,” said Theesfeld. Instead of searching for a biological explanation that encompasses all individuals with autism, researchers can now investigate the distinct genetic and biological processes driving each subtype.

This shift could reshape both autism research and clinical care – helping clinicians anticipate different trajectories in diagnosis, development and treatment. “The ability to define biologically meaningful autism subtypes is foundational to realising the vision of precision medicine for neurodevelopmental conditions,” said Sauerwald.

While the current work defines four subtypes, “this doesn’t mean there are only four classes,” said Litman. “It means we now have a data-driven framework that shows there are at least four – and that they are meaningful in both the clinic and the genome.”

Looking ahead

Beyond its contributions to understanding autism subtypes and their underlying biology, the study offers a powerful framework for characterising other complex, heterogeneous conditions and finding clinically relevant disease subtypes. As Theesfeld put it: “This opens the door to countless new scientific and clinical discoveries.”

Source: Princeton University

Categories : NeurologyTags :

Hormone Supplementation in Rhesus Monkeys Points to Potential Autism Treatment

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For years, Florida Tech’s Catherine Talbot, assistant professor of psychology, has worked to understand the sociality of male rhesus monkeys and how low-social monkeys can serve as a model for humans with autism. Her most recent findings show that replenishing a deficient hormone, vasopressin, helped the monkeys become more social without increasing their aggression – a discovery that could change autism treatment.

Currently, the Centers for Disease Control and Prevention report that one in 36 children in the United States is affected by autism spectrum disorder (ASD). That’s an increase from one in 44 children reported in 2018. Two FDA-approved treatments currently exist, Talbot said, but they only address associated symptoms, not the root of ASD. The boost in both prevalence and awareness of the disorder prompts the following question: What is the cause?

Some rhesus monkeys are naturally low-social, meaning they demonstrate poor social cognitive skills, while others are highly social. Their individual variation in sociality is comparable to how human sociality varies, ranging from people we consider social butterflies to those who are not interested in social interactions, similar to some people diagnosed with ASD, Talbot said. Her goal has been to understand how variations in biology and behaviour influence social cognition.

In their paper published in the journal PNAS, Talbot and researchers with Stanford, the University of California, Davis and the California National Primate Research Center explored vasopressin, a hormone that is known to contribute to mammalian social behaviour, as a potential therapeutic treatment that may ultimately help people with autism better function in society. Previous work from this research group found that vasopressin levels are lower in their low-social rhesus monkey model, as well as in a select group of people with ASD.

Previous studies testing vasopressin in rodents found that increased hormone levels caused more aggression. As a result, researchers warned against administering vasopressin as treatment, Talbot said. However, she argued that in those studies, vasopressin induced aggression in contexts where aggression is the socially appropriate response, such as guarding mates in their home territory, so the hormone may promote species-typical behaviour.

She also noted that the previous studies tested vasopressin in “neurotypical” rodents, as opposed to animals with low-social tendencies.

“It may be that individuals with the lowest levels of vasopressin may benefit the most from it – that is the step forward toward precision medicine that we now need to study,” Talbot said.

In her latest paper, Talbot and her co-authors tested how low-social monkeys, with low vasopressin levels and high autistic-like trait burden, responded to vasopressin supplementation to make up for their natural deficiency. They administered the hormone through a nebulizer, which the monkeys could opt into. For a few minutes each week, the monkeys voluntarily held their face up to a nebulizer to receive their dose while sipping white grape juice – a favorite among the monkeys, Talbot said.

After administering the hormone and verifying that it increased vasopressin levels in the central nervous system, the researchers wanted to see how the monkeys responded to both affiliative and aggressive stimuli by showing them videos depicting these behaviors. They also compared their ability to recognize and remember new objects and faces, which is another important social skill.

They found that normally low-social monkeys do not respond to social communication and were better at recognizing and remembering objects compared to faces, similar to some humans diagnosed with ASD. When the monkeys were given vasopressin, they began reciprocating affiliative, pro-social behaviors, but not aggression. It also improved their facial recognition memory, making it equivalent to their recognition memory of objects.

In other words, vasopressin “rescued” low-social monkeys’ ability to respond prosocially to others and to remember new faces. The treatment was successful – vasopressin selectively improved the social cognition of these low-social monkeys.

“It was really exciting to see this come to fruition after pouring so much work into this project and overcoming so many challenges,” Talbot said of her findings.

One of Talbot’s co-authors has already begun translating this work to cohorts of autism patients. She expects more clinical trials to follow.

In the immediate future, Talbot is examining how other, more complex social cognitive abilities like theory of mind – the ability to take the perspective of another – may differ in low-social monkeys compared to more social monkeys and how this relates to their underlying biology. Beyond that, Talbot hopes that they can target young monkeys who are “at-risk” of developing social deficits related to autism for vasopressin treatment to see if early intervention might help change their developmental trajectory and eventually translate this therapy to targeted human trials. 

Source: Florida Tech

Categories : Neurodegenerative Diseases NeurologyTags :

Autism Linked to Elevated Risk of Parkinson’s Disease

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People with an autism diagnosis are at a higher risk of developing Parkinson’s disease early in life, according to a large-scale study from Karolinska Institutet. The researchers believe that the two conditions can share underlying biological mechanisms.

The study, published in JAMA Neurology, is based on registry data from over two million people born in Sweden between 1974 and 1999 who were followed from the age of 20 up to the end of 2022.

The researchers interrogated a possible connection between the neuropsychiatric diagnosis Autism Spectrum Disorder (ASD), which affects an individual’s thought processes, behaviour and interpersonal communication, and early-onset Parkinson’s disease, a condition that affects locomotion and movement.

Possible dopamine involvment

The results show that people with an autism diagnosis were four times more likely to develop Parkinson’s disease than people without such a diagnosis, a correlation that remained when controlling for socioeconomic status, a genetic predisposition for mental illness or Parkinson’s disease and other such factors.

“This indicates that there can be shared biological drivers behind ASD and Parkinson’s disease,” says first author Weiyao Yin at the Department of Medical Epidemiology and Biostatistics. “One hypothesis is that the brain’s dopamine system is affected in both cases, since the neurotransmitter dopamine plays an important part in social behaviour and motion control.”

It is well-known that dopamine-producing neurons are degraded in Parkinson’s disease. Previous studies have also shown that dopamine is possibly implicated in autism, but more research needs to be done to confirm this.

“We hope that our results will eventually help to bring greater clarity to the underlying causes of both ASD and Parkinson’s disease,” says Dr Yin.

Medical checkups are vital

Depression and the use of antidepressants are common in people with autism, as are antipsychotic drugs, which are known for being able to cause Parkinson’s-like symptoms. When the researchers adjusted for these factors, the correlation between ASD and the later development of Parkinson’s disease was less salient, but the risk was still double.

The researchers point out that they only analysed early-onset Parkinson’s disease before the age of 50 and that the average age of participants by the end of the study was 34. The incidence of Parkinson’s disease was therefore very low. Future studies will need to examine if the elevated risk persists into older age. 

“The healthcare services need to keep people with ASD – a vulnerable group with high co-morbidity and a high use of psychotropics – under long-term observation,” says last author Sven Sandin, statistician and epidemiologist at the Department of Medical Epidemiology and Biostatistics. “At the same time, it’s important to remember that a Parkinson’s diagnosis before the age of 50 is very rare, including for people with autism.”

Source: Karolinska Institutet

Categories : NeurologyTags :

Study Sheds Light on How Autistic People Communicate

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There is no significant difference in the effectiveness of how autistic and non-autistic people communicate, according to a new study, challenging the stereotype that autistic people struggle to connect with others.

The findings, published in Nature Human Behaviour, suggest that social difficulties often faced by autistic people are more about differences in how autistic and non-autistic people communicate, rather than a lack of social ability in autistic individuals, experts say. 

Researchers hope the results of the study will help reduce the stigma surrounding autism, and lead to more effective communication support for autistic people.  

Direct communication

Autism is a lifelong neurodivergence and disability, and influences how people experience and interact with the world. 

Autistic people often communicate more directly and may struggle with reading social cues and body language, leading to differences in how they engage in conversation compared to non-autistic people. 

Story sharing

The study, led by experts from the University of Edinburgh, tested how effectively information was passed between 311 autistic and non-autistic people. 

Participants were tested in groups where everyone was autistic, everyone was non-autistic, or a combination of both. 

The first person in the group heard a story from the researcher, then passed it along to the next person. Each person had to remember and repeat the story, and the last person in the chain recalled the story aloud. 

The amount of information passed on at each point in the chain was scored to discern how effective participants were at sharing the story. Researchers found there were no differences between autistic, non-autistic, and mixed groups.  

Increased awareness

After the task, participants rated how much they enjoyed the interaction with the other participants, based on how friendly, easy, or awkward the exchange was.  

Researchers found that non-autistic people preferred interacting with others like themselves, and autistic people preferred learning from fellow autistic individuals. This is likely down to the different ways that autistic and non-autistic people communicate, experts say.  

The findings confirm similar findings from a previous smaller study undertaken by the same researchers. They say the new evidence should lead to increased understanding of autistic communication styles as a difference, not a deficiency.   

Autism has often been associated with social impairments, both colloquially and in clinical criteria. Researchers have spent a lot of time trying to ‘fix’ autistic communication, but this study shows that despite autistic and non-autistic people communicating differently it is just as successful. With opportunities for autistic people often limited by misconceptions and misunderstandings, this new research could lead the way to bridging the communication gap and create more inclusive spaces for all.

 Dr Catherine Crompton, Chancellor’s Fellow at the University of Edinburgh’s Centre for Clinical Brain Sciences

Categories : Mental HealthTags :

Differences in Object Grasping may Offer Simpler Diagnosis for Autism

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Getting a timely diagnosis of autism spectrum disorder is a major challenge, but new research out of York University shows that how young adults, and potentially children, grasp objects could offer a simpler way to diagnose someone on the autism spectrum.

The team, part of an international collaboration, used machine learning to analyse naturalistic hand movements – specifically, finger motions during grasping – in autistic and non-autistic individuals. Surprisingly, none of the simpler measures, such as time to grasp (reported to be slower in autistic adults), proved to be a reliable predictor.

“Our models were able to classify autism with approximately 85 per cent accuracy, suggesting this approach could potentially offer simpler, scalable tools for diagnosis,” says lead author, Associate Professor Erez Freud of York’s Department of Psychology and the Centre for Vision Research.

“Autism currently affects about one in 50 Canadian children, and timely, accessible diagnosis remains a major challenge. Our findings add to the growing body of research suggesting that subtle motor patterns may provide valuable diagnostic signals – something not yet widely leveraged in clinical practice.”

In addition to social and communication challenges, autism, a neurodevelopmental disorder, can include motor abnormalities which often show up in early childhood. The researchers say testing for these motor movements early could lead to faster diagnoses and intervention.

“The main behaviours markers for diagnosis are focused on those with relatively late onset and the motor markers that can be captured very early in childhood may thus lower age of diagnosis,” says Professor Batsheva Hadad of the University of Haifa, an expert in autism research and a key collaborator in this study.

Autistic and non-autistic young adult participants were asked to use their thumbs and index fingers, which had tracking markers attached, to grasp different blocks of varying size, lift each one and replace it in the same spot, and put their hand back in the starting position. The researchers used machine learning to analyse the participants’ finger movements as they made grasping motions.

Both groups of participants had normal IQ and were matched on age and intelligence. Young adults were used instead of children to rule out any differences in the findings due to delayed development.

The research found that subtle motor control differences can be captured effectively with more than 84% accuracy. The study also showed there were distinct kinematic properties in the grasping movements between autistic and non-autistic participants.

Analysis of naturalistic precision grasping tasks has not typically been used in previous studies, says Freud. Machine learning, however, provides researchers with a powerful new tool to analyse motor patterns, opening new ways to use movement data in the assessment of autism spectrum disorder.

The findings, says Freud, could lead to the development of more accessible and reliable diagnostic tools as well as timely intervention and support that could improve outcomes for autistic individuals in the future.

The paper, Effective autism classification through grasping kinematics, was published in the journal Autism Research.

Source: York University

Categories : VaccinesTags :

Why do False Claims that Vaccines Cause Autism Refuse to Die? Here are Nine Reasons

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Sven Bölte, Karolinska Institutet

The idea that autism is caused by vaccines has recently been revived by Robert F. Kennedy Jr., the presumptive nominee for US Secretary of Health and Human Services, as well as by president-elect Donald Trump. When asked about vaccines at a recent press conference, Trump reportedly said there was “something wrong” with rising autism rates, adding: “We’re going to find out about it.”

From a research perspective, there is little left to discover about vaccines used in long-standing nationwide vaccine programmes, such as diphtheria, tetanus, whooping cough, polio, measles, mumps and rubella. There is strong data from different countries showing that these vaccines do not cause autism or underlie the vast increase in autism diagnosis rates. So why do suspicions that vaccines cause autism remain?

1. Unawareness of evidence

Reliably and accurately communicating research results to the public is difficult. Research results usually stay in small research or clinical communities. Research is rarely accessible and researchers have few incentives to communicate findings outside of their scientific channels.

Popular media is typically superficial and often primarily interested in controversy that generates public attention.

2. Challenges understanding the science

Science is complicated and in medicine there are rarely absolute truths. The public, however, might expect clear consensus or have difficulty grasping the precise nuance of the science and its findings.

Evidence shows that vaccines do not cause autism or are the reason for increasing diagnosis rates. But it is also in the nature of science that it can neither verify nor exclude totally that vaccines contribute to autism in single individuals.

They protect against viruses and bacteria that cause significant levels of death and human suffering. Vaccine programmes thus have a good risk-to-benefit ratio but are not perfect.

3. Doubts of science

The public may have doubts about science and scientists. Science often delivers probabilities and models, not absolute truths.

This might be disappointing or misunderstood as being no better than individual attitudes or opinions. Although not true for vaccines and autism, evidence can be contradictory and difficult to replicate, reinforcing public doubts.

The human need for immediate and simple explanations for complex issues fuels misbelief. The public may also mistrust scientists due to experiences of elitism, reports of researchers not following good scientific practices, and recurring conspiracies that scientists are accomplices of the pharmaceutical industry.

4. Invisible success of vaccine programmes

Vaccination programmes are among the most cost-effective public health interventions available and have averted deaths and long-term disease on a global level in the last decades.

This success has made most diseases invisible in many countries today. The absence of these diseases generates implicit beliefs that vaccinations are unnecessary.

5. Vaccines cause immune reaction

To reach the goal of immunisation, vaccines must cause an immune reaction. Therefore, a transient inconvenient physical reaction is a sign of success, and the logic of vaccination.

This alone might be counterintuitive and feed doubts about vaccinations. Compared to other drugs, only the side-effects are experienced, and the main effect is preventive, not immediately experienced.

6. Parallelism of events

Autism is a neurodevelopmental condition commonly appearing in the first years of life. Initial autistic behaviour may coincide by chance with vaccination time points or follow them and mix with immune reactions.

Making a connection between vaccination and the appearance of autism in these cases is inevitable. But correlation is not causation.

7. Drugs in infancy without an emergency

Ethical issues arise when people make decisions for others regarding drugs or feel coerced to take them. This is particularly true for infancy where parents must consent for their babies.

It can feel intuitively wrong to interfere with nature and invasive to give a series of shots to a fragile human being in early development in the absence of a medical emergency.

8. Actual harms from less-well established vaccines

Benefits and risks cannot be generalised across all vaccines. Vaccines that are part of long-standing vaccination programmes have good evidence to back them, indicating a convincing risk-benefit ratio.

New vaccines are not ensured in the same way. For instance, the swine flu vaccine during the 2009 pandemic is suspected of having caused 1300 cases of narcolepsy in Europe.

We must distinguish between well-established vaccines and those developed within a short period. It seems that necessary discussions around the safety of less well-established vaccines affect trust in established ones.

9. Polarised debate of vaccines

Open societies build on trust, freedom of speech and debate – but also on shared responsibility. Recent years have seen a polarisation of views around many topics, including vaccinations, not at least fuelled by the COVID crisis.

The urgency of the situation and need for solidarity left little space and time for discussion in society and marginalised or stigmatised even moderate sceptics. The latter has surely harmed trust in vaccines more generally.

Sven Bölte, Professor of Child and Adolescent Psychiatric Science, Karolinska Institutet

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Categories : Mental HealthTags :

Social Skills not as Relevant for Autism Diagnosis than Thought

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People with autism are typically diagnosed by clinical observation and assessment. To deconstruct the clinical decision process, which is often subjective and difficult to describe, researchers used a large language model (LLM) to synthesize the behaviours and observations that are most indicative of an autism diagnosis. Their results, publishing in the Cell Press journal Cell, show that repetitive behaviours, special interests, and perception-based behaviours are most associated with an autism diagnosis.

These findings have potential to improve diagnostic guidelines for autism by decreasing the focus on social factors – which the established guidelines in the DSM-5 focus on but the model did not classify among the most relevant in diagnosing autism.

“Our goal was not to suggest that we could replace clinicians with AI tools for diagnosis,” says senior author Danilo Bzdok of the Mila Québec Artificial Intelligence Institute and McGill University in Montreal. “Rather, we sought to quantitatively define exactly what aspects of observed behaviour or patient history a clinician uses to reach a final diagnostic determination. In doing so, we hope to empower clinicians to work with diagnostic instruments that are more in line with their empirical realities.”

The scientists leveraged a transformer language model, which was pre-trained on about 489 million unique sentences. They then fine-tuned the LLM to predict the diagnostic outcome from a collection of more than 4000 reports written by clinicians working with patients considered for autism diagnosis. The reports, which were often used by multiple clinicians, included accounts of observed behaviour and relevant patient history but did not include a suggested diagnostic outcome.

The team developed a bespoke LLM module that pinpointed specific sentences in the reports that were most relevant to a correct diagnosis prediction. They then extracted the numerical representation of these highly autism-relevant sentences and compared them directly with the established diagnostic criteria enumerated in the DSM-5.

“Modern LLMs, with their advanced natural language processing capabilities, are natively suited to this textual analysis,” Bzdok says. “The key challenge we faced was in designing sentence-level interpretability tools to pinpoint the exact sentences, expressed by the healthcare professional themselves, that were most essential to a correct diagnosis prediction by the LLM.”

The researchers were surprised by how clearly the LLM was able to distinguish between the most diagnostically relevant criteria. For example, their framework flagged that repetitive behaviours, special interests, and perception-based behaviour were the criteria most relevant to autism. While these criteria are used in clinical settings, current criteria focus more on deficits in social interplay and lack of communication skills.

The authors note that there are limitations to this study, including a lack of geographical diversity. Additionally, the researchers did not analyse their results based on demographic variables, with the goal of making the conclusions more broadly applicable.

The team expects their framework will be helpful to researchers and medical professionals working with a range of psychiatric, mental health, and neurodevelopmental disorders in which clinical judgement forms the bulk of the diagnostic decision-making process.

“We expect this paper to be highly relevant to the broader autism community,” Bzdok says. “We hope that our paper motivates conversations about grounding diagnostic standards in more empirically derived criteria. We also hope it will establish common threads that link seemingly diverse clinical presentations of autism together.”

Source: ScienceDaily

Categories : NeurologyTags :

Risk Factor for Autism Linked to Y Chromosome

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Chromosomes. Credit: NIH

Increased risk for autism appears to be linked to the Y chromosome, a Geisinger study found, offering a new explanation for the greater prevalence of autism in males. The results were published in Nature Communications.

Autism spectrum disorder (ASD) is nearly four times more prevalent among males than females, but the reason for this disparity is not well understood. One common hypothesis involves the difference in sex chromosomes between males (XY) and females (XX).

“A leading theory in the field is that protective factors of the X chromosome lower autism risk in females,” said Matthew Oetjens, PhD, assistant professor at Geisinger’s Autism & Developmental Medicine Institute.

The Geisinger research team, led by Dr Oetjens and Alexander Berry, PhD, staff scientist, sought to determine the effects of the X and Y chromosomes on autism risk by examining ASD diagnoses in people with an abnormal number of X or Y chromosomes, a genetic condition known as sex chromosome aneuploidy.

The team analysed genetic and ASD diagnosis data on 177 416 patients enrolled in the Simons Foundation Powering Autism Research (SPARK) study and Geisinger’s MyCode Community Health Initiative.

They found that individuals with an additional X chromosome had no change in ASD risk, but that those with an additional Y chromosome were twice as likely to have an ASD diagnosis.

This suggests a risk factor associated with the Y chromosome instead of a protective factor associated with the X chromosome.

“While these may seem like two sides of the same coin, our results encourage us to look for autism risk factors on the Y chromosome instead of limiting our search to protective factors on the X chromosome,” Dr. Berry said.

“However, further research is needed to identify the specific risk factor associated with the Y chromosome.”

This analysis also confirms prior work by showing that the loss of an X or Y chromosome, known as Turner syndrome, is associated with a large increase in ASD risk. Further research is needed to determine whether the ASD risk factors associated with sex chromosome aneuploidy explains the sex difference in ASD prevalence.

Source: Geisinger Health System via Science Daily

Categories : Neurology PaediatricsTags :

Study Confirms the Utility of Screening for Autism in Toddlers Born Preterm

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New research published in Developmental Medicine & Child Neurology reveals that children born preterm are more likely to screen positive for autism than full-term children.

For the study, 9725 toddlers were screened at 15-, 18-, or 24-month well child visits using a test called the Modified Checklist for Autism in Toddlers, Revised.

Screening results that were positive for autism were most common among children born extremely preterm (51.35%) and least common among those born full-term (6.95%). Subsequent evaluations after positive screening revealed the following rates of autism diagnoses: 16.05% of extremely preterm, 2.00% of very preterm, 2.89% of moderately preterm, and 1.49% of full-term births.

Utilising the screening test at ages unadjusted for early birth was effective for identifying autism, as only a small number of preterm children (1.90%) who screened positive with the test did not receive a diagnosis of autism or other developmental delay following evaluation.

“With this research, we are hoping to help dissipate doubts that clinicians might have about the utility of screening for autism in toddlers born preterm,” said corresponding author Georgina Perez Liz, MD, of the AJ Drexel Autism Institute. “Low-cost, universal public health strategies such as screening can lead to less disparity in autism detection and help children on the spectrum start specific intervention and supports earlier in life.”

Source: Wiley

Categories : Neurology PaediatricsTags :

Early Sensorimotor Skill Differences can Guide Autism Diagnosis

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New research published in the journal iSCIENCE has revealed new insights into early sensorimotor features and cognitive abilities of toddlers who are later diagnosed with Autism Spectrum Disorder (ASD). The research, led by Kristina Denisova, a professor of Psychology and Neuroscience at the CUNY Graduate Center and Queens College, takes an important step toward better understanding ASD so that more precise, individually tailored interventions can be developed.

ASD, typically diagnosed around the ages of 4 to 5 years, is a neurodevelopmental disorder with complex and varied presentations, including atypical communication and restrictive and repetitive patterns of behaviour. Moreover, cognitive abilities are often lower in individuals with ASD. Despite the established link between lower intelligence quotient (IQ) in infancy and a future diagnosis of ASD, not all children with ASD exhibit lower cognitive abilities during infancy. The study addresses the critical gap in knowledge regarding the early features that differentiate children with varying cognitive abilities who later develop ASD.

The research team investigated the relationship between movement and cognitive abilities in toddlers before their ASD diagnosis, both during sleep and wakefulness. The study posed two key questions: Do ASD children with lower IQ exhibit altered movement during sleep compared to children with higher IQ? Additionally, are lower motor skills during wakefulness characteristic of lower-IQ children with ASD compared to those of higher-IQ ASD toddlers?

The research was conducted in two stages. In the first sample, the team examined sensorimotor features obtained from sleep functional magnetic resonance imaging (fMRI) in 111 toddlers with ASD. In the second, independent sample, they analysed sensorimotor functioning during wakefulness in over 1000 toddlers with ASD, categorised by lower vs higher cognitive abilities.

The findings revealed that toddlers with ASD and lower IQs have significantly altered sensorimotor features compared to toddlers with ASD and higher IQs. Interestingly, the sensorimotor features of higher-IQ ASD toddlers were nearly indistinguishable from typically developing (TD) toddlers. This suggests that a higher IQ may confer resilience to atypical sensorimotor functioning, and conversely, that poor sensorimotor functioning may be a key marker for lower IQ in childhood autism.

Moreover, the study found that lower-IQ ASD toddlers consistently exhibited lower gross motor skills across various age milestones (6, 12, 18, 24, and 30 months). This disruption in early sensorimotor learning during critical developmental periods indicates a potential vulnerability in the brain’s motor control circuitry, associated with lower cognitive abilities in toddlers who later receive an ASD diagnosis.

“The implications of these findings are far-reaching,” said Denisova. “They underscore the need for more precise, tailored interventions for children with ASD, particularly those with lower cognitive abilities. Interventions for lower-IQ autistic children may need to focus on enhancing both sensorimotor and cognitive skills, while interventions for higher-IQ autistic children might prioritise leveraging their strengths to mitigate potential mental health consequences.”

Denisova emphasised the importance of future research in this area, particularly involving underserved families who face barriers in accessing early intervention services.

Source: The Graduate Center, CUNY