ARX and autism: For example, the microtubule-interacting and trafficking (MIT) domain in SPAST contains missense variants implicated in hereditary spastic paraplegias27, the CAT C domain in SLC7A3 contains an autism-linked variant (S589T)28 and multiple domains in ARX outside MSA coverage (highlighted in Fig. 1d) contain missense variants linked to intellectual disability29–32.