Could the Polymorphisms of DOCK4 (rs147636134), SYNGAP1 (rs199759879), and FOXP1 (rs767001715) be the Primary Risk Factors for Bipolar Disorder and Autism Spectrum Disorder?

Autism spectrum disorder (ASD) and bipolar disorder (BD) are psychiatric diseases that may overlap in common neurodevelopmental and genetic basis. Forkhead Box P1 (FOXP1), Synaptic Ras GTPase-activating protein 1 (SYNGAP1), and Dedicator of Cytokinesis 4 (DOCK4) genes are critical for synaptic plasticity, neuronal communication, and brain development. This study aims to investigate the association of FOXP1 (rs767001715), SYNGAP1 (rs199759879), and DOCK4 (rs147636134) polymorphisms with ASD and BD and to determine the effects of genetic variations on disease pathogenesis in the Turkish population. This study was conducted with a total of 200 participants, including 50 ASD patients, 50 BD patients, and 100 healthy controls. DNA was isolated from peripheral blood samples, and FOXP1, SYNGAP1, and DOCK4 polymorphisms were genotyped using real-time PCR. The distribution of genetic variants was compared between patient groups and healthy controls. The chi-square test was applied for statistical analyses. In terms of FOXP1 (rs767001715), SYNGAP1 (rs199759879), and DOCK4 (rs147636134) polymorphisms examined in the study, no statistically significant difference was found between the ASD and BD patient groups and the healthy control group (p > 0.05) in the Turkish population. In addition, it was determined that these variants had allele frequencies compatible with global population data. However, due to the limited sample size, these results cannot be generalized. Further large-scale population analyses and functional studies are needed to investigate the association of these genes with ASD and BD in more detail.