This commentary is on the original article by Knuutinen et al. pages 1066–1074 of this issue. Leukodystrophies and leukoencephalopathies, a heterogeneous set conditions now often referred to as ‘genetic white matter disorders’ (GWMDs), have been problematic for diagnosis treatment. Three major phases marked studies into GWMDs. First, with advent widespread use magnetic resonance imaging (MRI) i...