The phenotypic spectrum of SPG56 has been expanded since the first description; to date, 32 affected individuals have been reported with pathogenic variants in CYP2U1. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 Additional clinical features may include cerebellar ataxia, dystonia, intellectual disability, cognitive delay, visual impairment, and subclinical peripheral neuropathy. The gene discussed is CYP2U1; the disease is Global developmental delay.