Serum levels of FGF-2, VEGF, and EGF and repetitive behaviors in pediatric ASD, OCD, and comorbid groups.

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) exhibit notable phenomenological overlaps. However, relatively few studies have simultaneously examined both the biological mechanisms and phenomenological overlaps of these two conditions. The aim of this study is to examine serum fibroblast growth factor 2 (FGF-2), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) levels and their phenomenological characteristics in patients diagnosed with ASD, OCD, and ASD + OCD. The study sample consisted of 84 children categorized into ASD, OCD, and comorbid ASD + OCD groups. Serum concentrations of FGF-2, VEGF, and EGF were quantified using the enzyme-linked immunosorbent assays method. Concurrent clinical severity and symptom profiles were rigorously assessed using the Childhood Autism Rating Scale, Children's Yale-Brown Obsessive Compulsive Scale, and Repetitive Behavior Scale-Revised. FGF-2 levels were significantly lower in the comorbid group p < .001, clearly distinguishing this from the two single-diagnosis groups. Serum VEGF and EGF levels did not differ significantly across the diagnostic groups (both p > .05). Repetitive behavioral symptoms differed significantly between the groups and were more prevalent in the comorbid group (p = .019). The results suggest that alterations in FGF-2 levels may be associated with the co-occurrence of ASD and OCD. Further studies are needed for a better understanding of this topic.