Autism: Study Finds Genetic Differences Linked to Age of Diagnosis
- Spectrum Stars
- Oct 21
- 2 min read
A new study published in the prestigious journal Nature (Zhang et al., 2025) offers fresh insight into the genetic and developmental origins of autism.
Rethinking Our Understanding of Autism
For a long time, researchers studied autism as a single condition, mainly of genetic origin.But this new research shows that the age at which autism is diagnosed plays a major role in how autistic traits and brain differences appear over time.
“Common genetic variants explain about 11% of the variance in the age of autism diagnosis — a level comparable to that of clinical and social factors,” the authors explain.
In other words, genes don’t tell the whole story: development, environment, and family context also have a strong influence on how autism manifests throughout life.
Two Autism Profiles Identified
The researchers analyzed several birth cohorts and identified two major developmental and genetic profiles:
Early-diagnosed profile
Detected in early childhood
Associated with more pronounced differences in communication and social interaction
Linked to genes influencing early brain development
Later-diagnosed profile
Often identified during adolescence
Associated with greater emotional or behavioral difficulties
Shows a stronger genetic correlation with ADHD and other mental health conditions
“These results indicate that early- and late-diagnosed autism follow distinct developmental trajectories,” the authors note.
Toward a More Nuanced View of the Autism Spectrum
This study challenges the idea of a “single autism” and calls for a more individualized approach to both diagnosis and support.
“Our findings have important implications for how we conceptualize autism and provide a model for explaining part of the diversity found across the spectrum.”
In other words, there isn’t just one autism, but multiple trajectories influenced by genetics, development, and environment.
Key Takeaways
The age of diagnosis is linked to genetic and developmental differences.
Some genetic signatures are more commonly associated with early diagnosis (traits appearing early in life), while others are linked to later diagnosis, often with co-occurring conditions such as ADHD.
Understanding autism means recognizing and integrating this diversity of experiences and pathways.
Spectrum Stars’ Perspective on the Study
This research does not question the fact that autism is a spectrum, encompassing a wide range of profiles. It simply shows that the age of diagnosis may be linked to different developmental and life trajectories, sometimes influenced by genetics.
It’s also important to remember that children diagnosed early often receive targeted support and early interventions, which can help their development.Conversely, a later diagnosis often means less support at key moments, leading to more challenges along the way.
In short, the observed differences are not purely genetic — they also stem from environmental factors, life context, and access to care.This study mainly helps us better understand the diversity of autistic experiences, while highlighting the crucial role of early identification and support.
📚 Source: Zhang et al., Polygenic and developmental profiles of autism differ by age at diagnosis, Nature, October 2025.🔗 Read the full article on Nature
