Transmethylation and Oxidative Biomarkers in Children with Autism Spectrum Disorder: A Cross Sectional Study.
Autistic children in this Indian sample carried extra oxidative and methylation stress markers, but the levels did not match their symptom severity.
01Research in Context
What this study did
Doctors in India drew blood from autistic children and matched controls. They measured two chemicals linked to cell stress: homocysteine and dityrosine. The goal was to see if these markers differ between groups and relate to autism severity.
What they found
Autistic kids had higher homocysteine and dityrosine levels than peers. Surprisingly, the extra chemicals did not track with how severe the autism looked. Higher numbers did not mean bigger challenges.
How this fits with other research
Ranjbar et al. (2014) saw the same oxidative stress theme in Iranian children, but used urine instead of blood. James et al. (2008) found similar methylation problems in parents years earlier, hinting the pattern runs in families.
Boswell et al. (2023) tell a different story. Their large review found no rise in tryptophan pathway markers. The two studies seem to clash, but they test separate chemical routes. One looks at oxidative stress, the other at tryptophan breakdown. Both can be true.
Beck et al. (2021) widen the lens. Their review links autism to broader metabolic risks like diabetes. Gulati et al. (2026) zoom in on two serum clues that may sit inside that bigger picture.
Why it matters
You cannot taste or see these chemicals, yet they may flag stress inside cells. For now, the numbers do not predict symptom level, so they are not ready for routine screening. Still, when you see feeding problems, fatigue, or growth issues, think metabolic. A quick referral for blood chemistry could rule out hidden risks and guide diet choices. Keep watching this line of work; future studies may link the stress markers to behavior and open new treatment paths.
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02At a glance
03Original abstract
We aimed to investigate the potential role of biomarkers of transmethylation, oxidative stress, and mitochondrial dysfunction in children with Autism Spectrum Disorder (ASD) by comparing them with that of typically developing children (TDC) controls. We also tried to correlate them with severity of autism, sensory issues, behavioural comorbidities and developmental quotients 119 with ASD and 52 age and sex matched typically developing children (TDC) controls were enrolled excluding those with chronic-illness or on any antioxidant therapy/multivitamins/anti-epileptic drugs. Median levels of biomarkers - serum homocysteine, cysteine, methionine, urine uric acid-to-creatinine ratio, arterial lactate, serum vitamin E, vitamin B12, folate, Nε-carboxymethyllysine, Nω- carboxymethylarginine (CMA), dityrosine and MTHFR C677T polymorphism were calculated. Children with ASD were further characterised using Childhood Autism Rating Scale-2, Childhood behavioural checklist, child sensory profile 2 caregiver questionnaire, Developmental Profile 3 for any correlation with the various biomarker levels. The median level of serum homocysteine in ASD group was 9 μmol/L(Range, 7- 16μmol/L), which was significantly higher than controls 7 μmol/L(Range, 4- 11μmol/L)(p=0.01). The prevalence of hyper-homocystinemia(>15μmol/L) was 13.4% in ASD as compared to 3.8% in controls with a significant difference(p=0.04). Dityrosine level was higher among ASD children when compared to TDC (9.8 vs 2.2 counts per second(cps), p<0.001). No significant correlation was found between prevalence of hyperhomocysteinemia and severity of autism/DQ/behavioural issues. No significant difference was found between the median levels of other biomarkers. Results support possible role of transmethylation defects and oxidative stress in ASD pathogenesis. Further studies are warranted for a better understanding of ASD pathogenesis.
Journal of autism and developmental disorders, 2026 · doi:10.1007/s12291-016-0619-0