Investigation of Homocysteine Levels in Jordanian Siblings of Autistic Children

Objectives To develop a sensitive and reproducible High-performance liquid chromatography-ultraviolet (HPLC-UV) method for quantifying plasma homocysteine (Hcy) in siblings of autistic individuals and age-matched controls in Jordan, and to investigate potential metabolic alterations associated with autism spectrum disorder (ASD). Materials and Methods Plasma samples were collected from siblings of autistic individuals and matched controls. Homocysteine levels were measured using a validated HPLC-UV method, demonstrating high accuracy, precision, and a low detection limit. Chemometric analyses, including hierarchical clustering, were applied to explore patterns related to age, gender, and volunteer type. Results The HPLC-UV method provided reliable quantification of Hcy in plasma. Siblings exhibited higher mean Hcy levels compared to controls, with significant inter-individual variability indicating heterogeneity in metabolic regulation. Female siblings had slightly higher Hcy concentrations than males, while age did not significantly influence Hcy levels. Chemometric analyses revealed distinct clustering: sibling samples did not segregate clearly by age or gender, whereas control samples clustered primarily by gender, suggesting potential metabolic dysregulation in siblings. Conclusion Altered homocysteine metabolism may represent a subtle biochemical endophenotype in siblings of individuals with ASD. These findings highlight the potential role of Hcy as a metabolic biomarker and underscore the need for further studies with larger cohorts to elucidate mechanistic links between Hcy dysregulation and neurodevelopmental outcomes.