B4GALNT1 and cerebellar ataxia: For example, pathogenic variants in the ceramide synthase gene CERS2 (Mosbech et al., 2014) cause epilepsy and ataxia, and mutations in genes involved in sphingolipid metabolism such as B4GALNT1, GBA2, and even FA2H, cause different forms of spasticity and ataxia, such as SPG26 (Wilkinson et al., 2005), SPG46 (Boukhris et al., 2010), and SPG35 (Dick et al., 2008), respectively.