Introduction:

Both environmental and genetic factors are considered in the etiology of Autism Spectrum Disorder (ASD). Heavy metals are considered as few of the possible environmental agents.

Methods:

The study is currently undergoing in a tertiary care teaching hospital in North India from June 2016 onwards, with an aim to enroll children with ASD (DSM V criteria) 3-12 years and age and sex matched typically developing children. One ml blood collected from each participant after informed consent of the caregiver is analyzed for blood heavy metals: Lead, Cadmium, Copper, Zinc, Manganese and Iron levels. The corresponding values were compared between both groups and correlated with Childhood Autism Rating Scale (CARS) score for autism severity and Childhood Behavior Check List (CBCL) for behavioral co-morbidities.

Results: Analysis done in June 2018 includes 56 children each with ASD (45 boys, 80%, 5.33+/-1.92 years, CARS score 37.83+/-3.79) and age and sex matched controls. Only blood lead levels of children with ASD was found to be more than that of controls with difference being statistically significant (p=0.01). Moderately positive correlation was found between blood lead levels and hyperactivity in ASD children (r=0.47), but no correlation with autism severity. No significant difference was found between blood levels of Cadmium, Copper, Zinc, Manganese and Iron.

Conclusion:

Blood lead levels in ASD children were higher than controls and correlated with severity of behavioral co-morbidities like hyperactivity. Interventional studies with chelating agents are needed to study, whether reducing blood lead levels is helpful in reducing symptom severity of ASD.