TUBB4A and Dystonia: Additionally, likely pathogenic or pathogenic variants were found in ATP1A3 (n = 5) and GNAO1 (n = 1) for genes causing combined dystonia, as well as ACTB (n = 1), IRF2BPL (n = 1), SPR (n = 1), and TUBB4A (n = 3) for genes linked to dystonia with other neurological or systemic features (Table S2).