Investigating the Role of Gluten Sensitivity in the Etiology of Autism Spectrum Disorder.

&lt;b&gt;Background and Objective:&lt;/b&gt; Autism Spectrum Disorder (ASD) is a range of neurodevelopmental disabilities that lack a clear etiology. To date, studies investigating the role of immune reactivity to gluten in ASD have been inconsistent. This study aimed to compare levels of gluten reactivity markers in 319 ASD patients to 172 of their unaffected siblings and 322 of unrelated healthy controls (UHC). &lt;b&gt;Materials and Methods:&lt;/b&gt; Patients younger than 12 years old diagnosed with ASD via experienced child psychiatrists and neuro-pediatricians were recruited and gluten reactivity markers and gastrointestinal (GI) complaints commonly found in children with ASD were also investigated. Serum levels of anti-gluten and anti-tissue transglutaminase IgA (anti-TTG IgA) were measured via ELISA. &lt;b&gt;Results:&lt;/b&gt; No significant differences were detected in IgA levels and IgG levels for anti-TTG among all groups (p<0.05). The anti-gliadin IgG levels were significantly higher in ASD patients and their siblings compared to the UHC group (p<0.05). Also, those IgG levels were not associated with any GI complaints or Electroencephalogram (EEG) abnormalities (p>0.05). &lt;b&gt;Conclusion:&lt;/b&gt; The data suggested gluten sensitivity has no role in ASD pathophysiology or its comorbid symptoms.