SPTAN1 and Ataxia: Furthermore, in 13 families (9.7%), we identified genes primarily associated with peripheral neuropathies (3 patients: SLC2A46, PDK3, MORC2), white matter disorders (3 patients: RNASEH2B, GFAP, ACER3), and neurodevelopmental disorders (5 patients: IRF2BPL, CTNNB1, DLG4, TAF1 and SPTAN1), which would have most likely been missed by gene panels targeting HSP/ataxia genes.