A recent study has identified four distinct subtypes of autism, highlighting the diversity within Autism Spectrum Disorder (ASD). The research, published in Nature Genetics, examined more than 5,000 autistic children and analyzed 230 traits, including repetitive behaviors, developmental milestones, and social interactions. The data was collected through questionnaires completed by parents as part of the SPARK cohort study.
Dr. Paige Kalika, a pediatric neurologist at the University of Miami Health System who works with children diagnosed with autism, commented on the findings. “This is why it’s called Autism Spectrum Disorder,” Dr. Kalika said. “We’ve known for some time that an autism diagnosis can represent multiple conditions bundled together with a lot of different symptoms. There can be a vast difference from one end of the spectrum to another.”
She described the new study as “the first of its kind to distinguish the complex disorder and confirm what so many of us understand about diagnosing and treating these children.” Dr. Kalika also noted that further research could identify additional subtypes, which may help develop targeted interventions such as behavioral therapies or medications.
The four subgroups identified in the study each have unique clinical and genetic profiles:
1. Social and Behavioral Challenges: This group comprises 37% of participants and is characterized by higher rates of anxiety, depression, ADHD, mild core autism traits like repetitive behaviors and social communication difficulties, but generally no significant developmental delays.
2. Moderate Challenges: Making up 34% of participants, this subgroup does not commonly have co-occurring psychiatric conditions or major developmental delays but shows core autism behaviors such as sensory sensitivities and challenges with conversation.
3. Mixed ASD with Developmental Delay
4. Broadly Affected
“These subtypes are just the beginning, a starting point. I expect that further research will identify more subtypes,” Dr. Kalika said.
According to a 2025 report from the Centers for Disease Control and Prevention (CDC), about one in 31 children in the United States are diagnosed with ASD by age eight—an increase from previous years (https://www.cdc.gov/autism/data-research/index.html0). The prevalence is higher among boys than girls and has recently increased among minority groups; Asian children have a prevalence rate of 3.82%, Black children at 3.66%, and Hispanic children at 3.30%.
Experts attribute rising diagnosis rates to greater awareness and improved access to diagnostic services. Dr. Kalika suggested that identifying subtypes could enhance diagnoses among adults since many people are not diagnosed until later in life.
“I see so many people who are not diagnosed until they’re adults, when their own children are diagnosed,” she said.
Research indicates that genetics play a significant role in ASD cases; approximately 20 percent of de novo cases can be linked directly to genetic factors (https://www.medrxiv.org/content/medrxiv/early/2024/08/16/2024.08.15.24312078.full.pdf). Other studies estimate that overall genetic contributions range from 40% to over 80%.
The identification of these subtypes may support more personalized treatments tailored to each group’s needs while also helping families plan for appropriate accommodations at home and school.
Dr. Kalika expressed optimism about future advances: “The idea is to target treatment to what people need, and this goes a long way in helping us achieve that.”
