Breakthrough autism research identifies four unique subtypes, revolutionizing diagnosis and care

New Breakthrough in Understanding Autism

Researchers have made a significant breakthrough in understanding autism by identifying four distinct types of the condition, each with its own unique genetic profile. This discovery could lead to better treatments and more personalized care for individuals with autism.

A team from Princeton University and the Simons Foundation conducted a comprehensive study involving 5,000 children participating in the SPARK research program, one of the largest autism studies in the United States. They analyzed various traits and behaviors, grouping the children into different categories based on their characteristics.

The researchers examined over 230 behavioral and developmental traits, including social interactions, repetitive behaviors, and sensory sensitivities. From this data, they identified four subtypes of autism: Social and Behavioral Challenges; Mixed Autism Spectrum Disorder (ASD) with Developmental Delay; Moderate Challenges; and Broadly Affected.

Each subtype was linked to specific genetic patterns and developmental trajectories. By comparing these subtypes with the children’s genetic profiles, the researchers found that DNA glitches can influence the development of autism before or after birth, highlighting the complexity of the condition.

Aviya Litman, a PhD student at Princeton University and co-lead author of the study, emphasized the importance of these findings. She stated that the subtypes represent different clinical presentations and outcomes, and importantly, they are connected to distinct underlying biology.

The study also revealed that common gene variants account for only about 20% of ASD diagnoses, leaving the remaining 80% to be influenced by environmental factors, DNA modifications, and gene-environment interactions that scientists are still trying to understand.

These insights could help parents better understand their children’s needs and guide them through developmental milestones with appropriate treatments, such as occupational therapy. Additionally, the findings may pave the way for new targeted gene therapies for those severely affected by autism.

To analyze the data from the 5,000 children, the researchers used a computational model that grouped children based on over 230 different traits, including repetitive behaviors, sound sensitivity, motor delays, and texture aversion. This approach led to the creation of four subtypes, each associated with unique genetic profiles and developmental paths.

Natalie Sauerwald, an associate research scientist at the Flatiron Institute and co-lead author, highlighted the significance of the findings. She noted that the study reveals multiple distinct narratives of autism, explaining why previous genetic studies often failed to produce consistent results.

Subtypes of Autism

1. Social and Behavioral Challenges: This group, comprising 37% of the study participants, displays classic autism traits such as social difficulties and repetitive behaviors. However, they typically meet developmental milestones on time. They often have co-occurring mental health conditions like ADHD, anxiety, depression, or OCD, which may not be apparent until they face increased social demands in school.

2. Mixed ASD with Developmental Delay: Representing 19% of the children, this group tends to lag behind their peers in hitting key developmental milestones, such as speaking and walking. They do not exhibit the anxiety or disruptive behaviors commonly seen in other subtypes. The term “mixed” reflects the variability in core autism traits among these children.

3. Moderate Challenges: Making up 34% of the study, this group represents the mildest form of autism. These children generally meet developmental milestones on time and do not exhibit the psychological difficulties seen in the first subtype. As a result, they may require less long-term care.

4. Broadly Affected: This group, accounting for 10% of the children, is the most severely impacted. They face challenges such as developmental delays, social and communication difficulties, repetitive behaviors, and co-occurring psychiatric conditions. They are more likely to carry damaging gene mutations that were not inherited from their parents.

Dr. Litman noted that these findings point to specific hypotheses linking various biological pathways to different presentations of autism. Understanding these differences is crucial for developing targeted interventions and improving diagnosis and treatment.

According to the CDC, the prevalence of autism has increased significantly over the years. In 2000, one in 150 children were diagnosed with ASD, but by 2020, this figure had risen to one in 36. A 2024 analysis of electronic health records for over 12.2 million Americans found that diagnoses increased by approximately 175% over 11 years.

Public health experts and healthcare professionals believe the rise in diagnoses is due to greater awareness, acceptance of neurodivergent individuals, and improved screening methods. Health and Human Services Secretary Robert F. Kennedy Jr. has prioritized identifying the causes of autism and understanding the reasons behind its increasing prevalence.

Senior study author Olga Troyanskaya, director of the Princeton Precision Health and Lewis-Sigler Institute for Integrative Genomics, emphasized the importance of understanding the genetics of autism. She stated that this knowledge is essential for revealing the biological mechanisms behind the condition, enabling earlier and more accurate diagnosis, and guiding personalized care.