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Spectrum: Autism Research News

Special Reports Curated collections of articles on special topics in autism.

Trends in autism research 2021

23 December 2021

Sex differences

Because autism is most often diagnosed in boys, researchers have a history of ignoring girls with the condition. But that bias is changing, as evidenced by an increasing number of studies on sex differences in autism.

Traits such as aggression and communication problems are related in autistic boys but not autistic girls, one study from 2021 showed. Another found that autistic women and girls pay more attention to faces than autistic men and boys do — which, along with the fact that autistic girls have an increased likelihood of having a co-occurring condition, may explain some of the diagnostic bias.

Researchers are grappling with what causes these differences, but autistic girls tend to have larger genetic mutations than autistic boys do — leading to sex differences in brain activity, according to one 2021 study, and lending support to the idea of a ‘female protective effect.’ Another 2021 analysis found that the X chromosome holds an outsized influence over brain development, which could serve to establish sex differences early on. Given these differences, researchers caution against using brain activity as an autism biomarker. Autistic men and women show different patterns of resting-state brain activity, for example, one 2021 analysis revealed.

Scroll through the study highlights below.

Brain activity patterns may distinguish girls with autism

by  /  2 June 2021

Atypical patterns of neuronal activity and gene expression in the striatum may characterize autism in girls, according to a new study.

X chromosome exerts extra influence on brain development

by  /  15 September 2021

The X chromosome holds stronger-than-expected genetic sway over the structure of several brain regions. The genes that may underlie this oversized influence have ties to autism.

Social attention shows sex difference in autism

by  /  14 May 2021

Autistic boys and men are less attuned to social stimuli than autistic girls and women are, according to new unpublished work.

Communication struggles may explain aggression in some autistic boys

by  /  29 March 2021

Poor communication skills predict aggression in autistic boys, according to a new study. In autistic girls, communication and aggression may not be related.

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“We cannot assume that what we learn about males with autism holds true for females with autism. That might sound obvious, but girls and women with [autism] are often underrepresented in research samples.”

Emily Neuhaus, assistant professor of psychiatry and behavioral sciences at the University of Washington in Seattle

The ‘dark genome’

In the search for autism-linked mutations, researchers have focused mainly on genes — which make up only 2 percent of the genome. This year, however, autism scientists made inroads exploring vast stretches of DNA that don’t code for proteins. One sequencing study implicated what may be the first three spontaneous mutations in noncoding regions tied to the condition. Such mutations contribute to autism in at least 2 percent of people on the spectrum, according to another 2021 study. And noncoding mutations play a role in the ‘second hit’ theory of autism genetics, an analysis from November shows, amplifying the effects of mutations in the autism-linked chromosomal region 16p12.1.

Noncoding mutations may also shape when and where autism-linked genes are most active during brain development, which a new atlas of gene expression in the fetal brain maps out for mid-gestation. And mutations in enhancers — noncoding regions that boost gene expression — occur far more often in people with autism than in those without, according to an analysis of postmortem brain tissue from this past January.

A mosaic made of different colors of maize (corn) kernels depicting DNA.

Two studies highlight role of ‘mosaic’ mutations in autism

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

circuit board style lines in black and white suggest sperm approaching an egg.

Mutations linked to autism may be detectable in men’s sperm

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Abstraction of human genome data with some sections circled.

Analysis ups estimate of spontaneous mutations’ role in autism

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Mutations in the noncoding genome contribute to autism

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Ultra-rare variants point to new autism candidate genes

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

A gloved-hand holds up a vial against a background of colorful lights that represent a sequenced genome.

Genetic effects stack up in some people with autism

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

The current evidence does not establish meaningful specificity of any genes for autism. Similarly, there are no molecular pathways or neural pathways or networks that are known to be uniquely associated with autism when disrupted.”

David Ledbetter, chief clinical officer of Dascena in Oakland, California

Improving screening

Researchers deployed several new strategies this year to try to upgrade autism screening and, in many cases, render the process remote — although questions remain about some app-based systems. A new deep-learning model flags autistic toddlers based on the patterns of other conditions noted in the children’s medical records. A mobile app that tracks toddlers’ gaze patterns accurately distinguishes those with autism from their non-autistic peers. And a web app for tracking pupillary responses — which can be slower in people with autism — proved reliable as well this year. Wearable devices could also help clinicians detect early signs of the condition, new works shows.

Other teams are seeking to optimize existing screening practices. This past year, one group uncovered a long-standing error in the guidelines for one popular autism screening test. Another team boosted autism screening rates at pediatric clinics in Utah by, among other changes, adding reminders to electronic health records. And a growing number of researchers is pushing to expand genetic screening for newborns to improve early identification of some autism-linked conditions.

Scroll through the study highlights below.

The push to screen newborns for rare autism-linked genetic conditions

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Tweaking clinic protocols improves autism screening rates

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

How two graduate students uncovered a critical error in autism screening guidelines

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Green light for diagnostic autism app raises questions, concerns

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

Web app tracks pupil size in people, mice

by  /  12 July 2021

Mosaic mutations, which affect only some of the body’s cells, play a small but meaningful role in autism. Though they are difficult to study, researchers are working to master their complexity.

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News

Video: Wearable sensors pick up early signs of autism

Audio and motion-sensor recordings offer a remote window into a baby’s first years and make it easier for families to participate in research.

“The wait time from getting a positive in an M-CHAT screen to getting a targeted autism assessment might take a year.”

Ishanu Chattopadhyay, assistant professor of medicine at the University of Chicago in Illinois

Participatory research

Participatory research in autism is not new, but conversations around the practice — which involves close collaboration between scientists and autistic people to design and conduct studies — reached new heights this year. A comprehensive personal account from autistic postdoctoral researcher Monique Botha tackled unacknowledged ableism in the autism research community. Intense debate followed the launch and subsequent pause of Spectrum 10K, a planned genome-sequencing project in the United Kingdom that some autistic people saw as misaligned with its stated goals of helping people on the spectrum; the project’s leaders announced that they would engage in a deeper dialogue with autistic people before restarting. And a rare look at researchers’ perceptions of the process reiterated that researchers’ willingness to work with autistic people is only the first step.

Spectrum took a deep dive to explore successful partnerships between autistic and non-autistic researchers and produced a primer on best practices for scientists who are new to the concept.

Backlash from autistic community pauses research, exposes communication gaps

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Illustration shows researcher hand and the hand of a person with autism, holding a research paper aloft. Tone is optimistic.

Six steps to engaging in participatory autism research

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Meet the autistic scientists redefining autism research

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Speech bubble formed by a network of communication

Community Newsletter: Gene-by-sex effects, biosecurity laws, participatory research

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Speech bubble formed by a network of communication

Community Newsletter: Ableism in autism research

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Speech bubble formed by a network of communication

Community Newsletter: Participatory research, burnout, sleep Kismet

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

“Too much autism research fails to acknowledge autistics as people who can read and make valuable contributions to the field. Instead, it casts them as little more than passive study participants or recipients of treatment.”

Elle Loughran, Laidlaw scholar at Trinity College Dublin in Ireland

Convergence

Because autism is such a diverse condition, researchers have long sought to identify common ground — including shared mechanistic routes to multiple forms of it. This year, scientists plotted several new points of convergence on that map, several of which involve shared functions among autism-linked genes: Some genes play a role in the early development of neurons, according to a study of frog embryos, whereas others seem to be important for the function of the brain’s glial cells, an analysis of gene expression in single brain cells showed.

A few autism-linked genes converge on the same cellular neighborhoods, with high activity levels in the brain’s anterodorsal thalamus; diminishing the genes’ activity there led to neuronal hyperexcitability and memory problems in mice, one study showed. And six mouse models of autism became more sociable after drug treatments that boost levels of the neurotransmitter serotonin, according to work that flags part of the brain’s social-reward system, the nucleus accumbens, as another point of convergence.

Zooming out further revealed that distinct forms of autism may share distinct activity signatures across the brain, according to scans from 16 mouse models. One signature — marked by a pattern of brain overconnectivity — arises from a surplus of synapses, mouse work suggests.

Scroll through the study highlights below.

Genes tied to autism, developmental delay, schizophrenia share functions

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Autism-related conditions converge on same loss of DNA tags

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Brain’s sensory processor may prompt memory problems in autism

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Drugs boost serotonin, socialization in multiple autism mouse models

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

Synaptic overgrowth, hyperconnectivity may define autism subtype

by  /  14 January 2021

Five collaborations involving autistic scientists and experts are advancing autism research, from lending support for theories of the condition to shoring up trials of new treatments.

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Mutations in frogs point to autism genes’ shared role in neurogenesis
transparent tadpole
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Frog frames: Mutations in multiple autism-linked genes have similar effects on the developing central nervous system of Xenopus tropicalis tadpoles.

All images courtesy Helen Willsey

Full transparency: Researchers can use Xenopus tropicalis tadpoles to readily observe stages of brain development that occur in utero in humans and other animals.

Half time: Researchers can edit a gene in one half of Xenopus embryos (red) without altering the other (gray).

Resizing: A tadpole with a mutation in the autism-linked gene DYRK1A in cells on the right side of its body has a smaller right forebrain (upper right) than left forebrain.

Face to face: Dyes that bind to different cells highlight muscles (red) and nuclear DNA (blue) in a tadpole. Thanks to gene editing, the developing brain glows green.

Body parts: Colorful markers reveal muscles, DNA nuclei and the central nervous system in a Xenopus laevis tadpole.

“Expecting that we were going to find a common signature for such a heterogeneous condition was sort of a pipe dream.”

Kaustubh Supekar, clinical assistant professor of psychiatry and behavioral sciences at Stanford University in California