Recent genome-wide association studies (GWAS) have reported an association between SNPs in gene encoding alpha-2,3-sialyltransferase-III (ST3GAL3) and factors regulating ganglioside function and the incidence of schizophrenia, attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorders (ASD). This evidence concerns the gene ST3GAL3 and attention deficit-hyperactivity disorder.