LOW SERUM OXYTOCIN LEVELS IN PROBANDS WITH AUTISM AND THEIR FIRST DEGREE RELATIVE-A PRELIMINARY CASE FOR OXYTOCIN AS AN ENDOPHENOTYPE

Abstract

Author(s): Ahmed Abd El Gawad*

Oxytocin (OT) is a peptide hormone that has been reported to be associated with attachment, social memory, emotional cognition, and social interaction. Metabolic abnormalities of OT have exhibited a significant association with impairment in social interaction and communication in Autism Spectrum Disorders (ASD) individuals. Several exogenous OT treatments have managed to normalize impaired social functioning among individuals with ASD. The serum Oxytocin levels in patients with autism, their age, and sex-matched healthy control groups and First-Degree Relatives (FDRs) of patients with autism, and the association between Oxytocin levels and socialization have not been studied.

Aims: This study aimed to assess and compare the serum OT levels in patients with autism, their FDRs, and age-sex-matched healthy controls, and examine the relationship between OT levels & socialization.

Settings and design: Cross-sectional hospital-based study on 20 patients diagnosed with autism according to ICD-10 DCR, 20 their FDRs and 20 age-sex matched healthy controlstion.

Materials and methods: A total of 60, 20 patients were diagnosed with autism according to ICD-10 DCR (n=20), 20 their FDRs (siblings) (n=20) and 20 age-sex matched healthy controls (n=20). Serum oxytocin level was measured using an Enzyme-Linked Immunosorbent Assay (ELISA). Assessments included the INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD) and the Indian Scale for Assessment of Autism (ISAA).

Results: A total of 20 autism patients, 20 of their FDRs, and 20 age and sex-matched healthy controls completed the study. The study showed a significant difference in Serum Oxytocin levels among the autism patient group, their first-degree relative, and the healthy control group (p<0.001). Post-hoc analysis has revealed that there is a significantly high level of Serum Oxytocin levels in controls compared to the patient group and FDRs. However, there is no significant difference in Serum Oxytocin levels between the patient group and FDRs. The assessment showed significant differences among the patient group and FDRs in ISAA domains of Social relationship and reciprocity, Emotional responsiveness, Speech-language and communication, behavior patterns, sensory aspects, cognitive component & total score (p<0.001). There was no significant correlation between Serum Oxytocin levels with age and ISAA domains of Social relationship and reciprocity, Emotional responsiveness, Speech language and communication, behavior patterns, sensory aspects, or cognitive component in the study group.

Conclusion: The study found significantly lower values of OT in patients and FDRs when compared to controls, suggesting a possible role of Oxytocin as a trait marker in autism. Also found that lower levels of Oxytocin in FDRs have no relation with socialization in FDRs as ISAA scores were significantly higher in FDRs compared to patients.