The spectrum of X-linked neurological disorders that are associated with decreased PRPS1 function includes Arts syndrome, Charcot-Marie-Tooth disease 5 (CMTX5), nonsyndromic sensorineural deafness 2 (DFN2), and more recently retinal dystrophy [22,23,24]. This evidence concerns the gene PRPS1 and Lethal ataxia with deafness and optic atrophy.