Autism Subtypes: Research from Princeton University and the Simons Foundation
An often used expression about Autism popularized by Autism advocate Dr. Stephen Shore is: “If you’ve met one person with Autism, you’ve met one person with Autism.” This phrase suggests that Autism is indeed a diverse spectrum, and people with Autism have unique strengths, challenges, and experiences that vary greatly from one person to the next. Information about Autism has become increasingly available to the public in recent years, and it is now well understood that there is no single set of specific symptoms that accurately describes all people on the spectrum. Recent research from Princeton University and the Simons Foundation (senior author Olga Troyanskaya) is helping to identify four clinically and biologically distinct subtypes of Autism, which is useful not only in understanding genetic contributions to Autism, but also in expanding the potential for personalized support and care. The Princeton/ Simons Foundation research is summarized here.
Highlights of the Princeton and Simons Foundation Autism research include:
- A study sample of 5000 children
- A computational model grouping individuals based on their combinations of over 230 behavioral traits
- The discovery of Autism subtypes with distinct genetic profiles and developmental trajectories, published in July of 2025 in Nature Genetics.
- The data shows there are at least four meaningful subtypes, but does not rule out the possibility that other subtypes may exist.
- Divergent biological processes were identified for each subtype, helping explain why past genetic studies often fell short. Genetic patterns could more readily be identified when the participants were separated into subtypes.
- Autism subtypes differ in the timing of genetic disruptions’ effects on brain development (with some gene mutations not present before birth, and becoming active later in childhood).
- Understanding one’s Autism subtype may help lead to more targeted monitoring of development, treatment tailored to the individual, and personally relevant support and accommodations at school and work.
What are the Proposed Four Subtypes of Autism?
The four subtypes of Autism described in the Princeton/ Simons Foundation research include 1. Social and Behavioral Challenges, 2. Mixed ASD with Developmental Delay, 3. Moderate Challenges, and 4. Broadly Affected. Each subtype is noted to exhibit distinct traits, and distinct patterns of genetic variation.
1. Social and Behavioral Challenges Group
Individuals in the Social and Behavioral Challenges group exhibit social challenges and repetitive behaviors, but typically reach developmental milestones (such as speech and walking) at similar rates as neurotypical children. They often also experience co-occurring conditions including Attention Deficit Hyperactivity Disorder, anxiety, depression, or anxiety. This group constituted about 37% of the study participants. Diagnosis is often later in this subtype, and mutations were found in genes that become active later in childhood (whereas the genetic impact of Autism was previously thought to occur before birth).
2. Mixed ASD with Developmental Delay Group
Those in the Mixed ASD with Developmental Delay group tend to reach developmental milestones later than neurotypical children, but do not typically show signs of depression, anxiety, or disruptive behaviors. Differences are noted in this group as regards repetitive behaviors and social challenges. This group constituted about 19% of study participants. Children in this group were most likely to carry rare inherited genetic variants.
3. Moderate Challenges Group
Individuals in the Moderate Challenges group exhibit core Autism-related behaviors, but to a lesser extent than those in the other groups, and typically reach developmental milestones similarly to neurotypical children. They generally do not experience co-occurring psychiatric conditions, and this group constituted about 34% of study participants.
4. Broadly Affected Group
Those in the Broadly Affected group exhibit more extreme and wide-ranging challenges than those in other groups. These challenges include developmental delays, social and communication difficulties, repetitive behaviors, and co-occurring psychiatric conditions (such as anxiety, depression, and mood dysregulation). This group constituted about 10% of study participants. Children in this group showed the highest proportion of de novo genetic mutations (those not inherited from either parent).
The Princeton/ Simons Foundation research offers exciting findings, helpful conceptualization of Autism, and suggestions for future research.
If you feel you may have neurological differences that are not yet diagnosed; you have a known diagnosis and you are in need of updated recommendations for accommodations, modifications, and other personal or work-related needs; or you would like to learn more about the assessment process, you can find more information on my page: Autism Assessment for Adults. If you prefer, please feel free to reach out to me by email at amy@amyblackmonphd.com.