Stx1a, also known as Shiga toxin 1a in the context of bacterial toxins, is a major subunit of Shiga toxin. Shiga toxin is one of the most potent bacterial toxins, with Stx1a being found in Shigella dysenteriae 1 and some Escherichia coli serogroups. The Stxs (including Stx1a) consist of an A subunit that halts protein synthesis in target cells by injuring the eukaryotic ribosome, and a B pentamer that binds to the cellular receptor globotriaosylceramide on endothelial cells [3].

In the context of human health, certain genes like STX1A (encoding syntaxin 1A) have been associated with attention-deficit/hyperactive disorder (ADHD). A case-control study in the Chinese Han population found that genetic variants of STX1A contribute to the susceptibility of children ADHD. Specifically, rs3793243 GG genotype carriers had a lower risk of ADHD compared with AA genotype, and rs875342 was also associated with children ADHD [2]. Additionally, ultra-rare variants in STX1A cause a neurodevelopmental disorder with or without epilepsy. Missense variants in STX1A are mainly associated with epilepsy, while in-frame deletions are related to intellectual disability and autistic behavior [1].

In conclusion, Stx1a in the form of the bacterial toxin has well-defined functions in disrupting eukaryotic cell protein synthesis. Regarding the STX1A gene, its variants are linked to neurodevelopmental disorders such as ADHD and other conditions involving intellectual disability, autism, and epilepsy. Research on these aspects helps in understanding the genetic basis of such disorders and may potentially lead to better diagnostic and treatment strategies.