Interestingly, TTC21B resides in the 2q24.3 locus, a region that contains the well-characterized epilepsy risk gene SCN1A (Claes et al., 2001, 2009; Meng et al., 2013; Parihar and Ganesh, 2013; International League Against Epilepsy Consortium on Complex Epilepsies, 2014; Haigh et al., 2021). The gene discussed is SCN1A; the disease is epilepsy.