TUBB4A and torsion dystonia 4: In one large Australian family with fully penetrant juvenile-adult-onset “whispering dysphonia,” occasional generalization and alcohol benefit (Wilcox et al., 2011), the p.R2G mutation in the TUBB4a gene (DYT4, encoding the isoform a of b-Tubulin) has been identified by exome sequencing (Hersheson et al., 2012).