Abstract
This study is the first to investigate potential correlations between blood groups, Rh factors, and Autism Spectrum Disorder (ASD) within a diverse dataset of 2,390 participants from multiple regions in Iraq. The participants included children with ASD, children with other neurodevelopmental disorders, typically developing children and their parents. Using chi-square tests, logistic regression analysis, and machine learning algorithms, the findings revealed that the O + blood group was the most prevalent across all groups. Importantly, logistic regression analysis identified the AB + blood group as being associated with a significantly lower risk of ASD, suggesting a novel protective factor. No significant associations were observed between other blood groups, Rh factors, and ASD risk. Additionally, the study found no statistically significant differences in blood group distributions among children with ASD, other neurodevelopmental disorders, and typically developing children. These results provide new insights into the potential immunogenetic contributions to ASD and emphasize the need for further research to confirm the protective effect of the AB + blood group. Such studies may help unravel the genetic, immunological, and environmental mechanisms underlying ASD and support the development of targeted diagnostic and preventative strategies.