Presymptomatic Biological, Structural, and Functional Diagnostic Biomarkers of Autism Spectrum Disorder.
Stick to behavioral tools; biological early-warning tests for autism are still research toys.
01Research in Context
What this study did
Wang et al. (2025) pulled together every paper they could find on early warning signs that show up before autism is diagnosed. They looked at three kinds of clues: tiny molecules in blood or spinal fluid, brain pictures from MRI, and how brain cells fire during simple tasks. The team only kept studies that watched babies who later got an autism diagnosis.
What they found
Most biomarkers looked exciting in small labs but fell apart when teams tried to repeat them. A few patterns keep popping up—slightly different head growth, certain gene snippets, and subtle EEG quirks—but none are ready for your clinic yet. The authors stamp every finding with a big "preliminary" label.
How this fits with other research
Hu et al. (2017) and Ecker (2017) echo the same warning: micro-RNAs and brain scans look cool on paper, yet they give too many false alarms for real-world use. Baker et al. (2025) focused only on gut and metabolic markers and reached the identical "not ready" verdict, showing the problem spans body systems.
Moss et al. (2009) widens the lens to kids with fragile-X, Rett, and other syndromes. They show that autism-like behaviors in these groups look different from idiopathic ASD, so any future blood test must be tuned by genetic subtype—something Wang’s broad review barely touches.
Atladóttir et al. (2015) studied birth records and found higher neonatal illness in babies later diagnosed with ASD, but the same risks appear in cerebral palsy and ADHD. Their medical-chart approach gives you cheaper, quicker red flags than Wang’s high-tech markers, yet neither route offers a unique autism signature.
Why it matters
For now, keep doing what works: use standardized checklists, parent interviews, and direct observation. Let the medical team order genetic tests only when syndromic features show up. Track biomarker news, but don’t wait for a lab result to start EIBI or parent training—early behavior therapy still beats any experimental blood draw.
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02At a glance
03Original abstract
Autism spectrum disorder (ASD) is a common neurodevelopmental disorder clinically diagnosed by persistent deficits in three areas of social communication and interaction, plus at least two of four types of restricted repetitive behaviors. ASD has been shown to be caused by genetic predisposition and environmental factors; however, the heterogeneity of ASD complicates its diagnosis and treatment. Early behavioral interventions have shown significant benefits, emphasizing the urgent need for reliable diagnostic biomarkers to enhance long‐term outcomes. Here we provide a systematic review that outlines current findings on genetic and neurological biomarkers for presymptomatic ASD diagnoses, assessed prior to the observation of behavioral manifestations. Specifically, we offer insights into the mechanisms of presymptomatic neurological, biological, structural, and functional markers for ASD, compare outcomes across studies, and critically assess their limitations and implications. Recent findings highlight genotype‐guided therapeutic strategies in animal models, such as dietary zinc supplementation for reversing ASD‐associated behaviors by synaptic deficits. However, the differential efficacy based on underlying genotypes, along with challenges in identifying reliable genomic biomarkers prior to symptom onset, indicates the need for further research. Notably, recent advancements in imaging technologies like magnetic resonance imaging, electroencephalography, and pupillometry have shown promising markers in neonates, and at 3 and 9 months old, respectively. Newer developments in magnetoencephalography hardware can facilitate the much‐needed infant ASD studies. It is important to note that many of these biomarker findings are preliminary, and further validation for clinical use is required. Continued research is needed to advance the practicality, reliability, and acceptability of these biomarkers to improve ASD diagnosis and treatment strategies.
Journal of Neurochemistry, 2025 · doi:10.1111/jnc.70088