PRPPS (Prps1, Prps1l1, Prps2) was previously reported to be affected by amino acid depletion55,59, while mutations in Prps1 have been associated with hyperuricemia, hyperuricosuria, hypotonia, and ataxia and gain-of-function mutation results in PRS-1 superactivity60. The gene discussed is PRPS1L1; the disease is cerebellar ataxia.