KATNB1 and cerebral malformation: Interestingly, similar subcortical heterotopias group 1a have been associated with mutations in the genes encoding the katanin subunit KATNB1, also involved in microtubule severing at the centrosome, and the microtubule subunit tubulin β (TUBB), suggesting a link between microtubule assembly and these brain malformations (39).