VPS13A and Choreoacanthocytosis: Mutations in the vacuolar protein sorting-associated protein A (VPS13A) are associated with ChAc (Ueno et al. 2001; Rampoldi et al. 2001); however, the clinical phenotype differs among the cases even with the same mutation, suggesting complex gene–gene interactions or gene–environment interactions as modifying factors (Niemelä et al. 2020; Tomiyasu et al. 2012).