| Phenotype details |
age at deterioration 25y; developmental delay, intellectual disability; progressive psychomotor slowing adolescence/adulthood; Rett-like features; dystonia; Parkinsonism; l-DOPA responsive; limited expressive language; no sleep problems; EEG diffuse background slowing with bursts of generalized 3/s spike and wave discharges; staring, absence or atonic seizures; no ocular defects; T2 hypointense substantia nigra and globus pallidus (high iron); T1 hyperintense ‘halo’ midbrain; cerebral atrophy; no cerebellar atrophy |