SCYL1 and neurodegenerative disease: Spinocerebellar ataxia, autosomal recessive 21 is the only disease listed in OMIM under SCYL1. However, Lenz et al. reported a novel SCYL1-related phenotype known as CALFAN (low γ-glutamyl-transferase cholestasis, acute liver failure, and neurodegeneration) syndrome [8].