A rare mitochondrial disease with characteristics of a distinctive MRI pattern of cavitating leucodystrophy, predominantly in the posterior region of the cerebral hemispheres. The clinical picture varies widely between acute neurometabolic decompensation in infancy with loss of developmental milestones, seizures and pyramidal signs rapidly evolving into spastic tetraparesis, to subtle neurological symptoms presenting in adolescence. The disease course tends to stabilise over time in most patients and marked recovery of milestones may be observed. [from SNOMEDCT_US]