This disease has been described in families of Roma and Sudanese descent.29,30UBA5 variants cause a subtype of early infantile epileptic encephalopathy, with fibroblasts from the affected individuals suggesting dysfunctional E1-like activity in the mutants (EIEE44, OMIM 617132).31,32UBA5 variants have also been reported in individuals with an autosomal recessive form of spinocerebellar ataxia (SCAR24, OMIM 617133).33 Variants in UFC1, which encodes the E2 component, cause an autosomal recessive neurodevelopmental disorder with spasticity and poor growth (NEDSG, OMIM 618076).30,34. This evidence concerns the gene UFC1 and cerebellar ataxia.