| Phenotype details |
age at deterioration 15y; developmental delay, intellectual disability; progressive psychomotor slowing adolescence/adulthood; Rett-like features; dystonia; minimal Parkinsonism, only rigidity; limited expressive language; no sleep problems; staring, absence or atonic seizures; high myopia; T2 hypointense substantia nigra and globus pallidus (high iron); no T1 hyperintense ‘halo’ midbrain; cerebral atrophy; cerebellar atrophy |