A disorder caused by a mutation of the DPYD gene with a spectrum of manifestations from asymptomatic individuals to seizures (45%), ocular abnormalities (23%), autism (18%), growth retardation (18%), microcephaly (14%) or mild dysmorphic features
On imaging there is partial agenesis of the corpus callosum, intracerebral hamartomas, and increased T2 signal of the white matter. There is increased grey white matter differentiation due to decreased T1 signal of the white matter.