ATM and Dystonia: The classical myoclonus‐dystonia phenotype is based on genetic defects in the MYC/DYT‐SGCE gene in about 50% of cases.101 Other disorders that can give rise to a myoclonus‐dystonia phenotype include MYC/DYT‐KCTD17, DYT‐ANO3, ATX‐PRKCG, ATX‐ATM, CHOR/DYT‐ADCY5, CHOR‐NKX2‐1, and maternal uniparental disomy with regions of heterodisomy and isodysomy on chromosome 7 (mUPD7), which is based on the loss of function of the SGCE gene.