Elevated Plasma X-Linked Neuroligin 4 Expression Is Associated with Autism Spectrum Disorder

Abstract

Objectives: In this study, we compared plasma levels of neuroligin 4 (NLGN4) in children with autism versus matched healthy controls to examine a possible correlation between plasma NLGN4 and degree of autism severity as well as social impairment in autistic patients. Subjects and Methods: 88 autistic patients aged 3-12 years and 33 age- and sex-matched controls aged 3-9 years were recruited. Plasma levels of NLGN4 were determined using a commercial enzyme-linked immunoassay (ELISA). The Childhood Autism Rating Scale (CARS) and the Social Responsiveness Scale (SRS) were used to assess cognitive dysfunction and social impairment in autistic patients. Results: Plasma levels of NLGN4 were significantly higher (p = 0.001) in autistic children than in healthy controls. Despite alterations in the levels of NLGN4 in the subgroups of the autistic children, no correlation between plasma concentration of NLGN4 and cognitive problems or social impairment was observed (p> 0.05). Conclusion: Increased plasma concentrations of NLGN4 may play a role in the pathogenesis of autism, and it could be a valuable biomarker for autism. Further studies with larger sample sizes are warranted to validate this finding and also to explore the potential links between NLGN4 and the features of autism.