WDR62 and lissencephaly spectrum disorders: When mutations in WDR62 were initially discovered15, it became apparent that they cause a form of microcephaly invariably accompanied by a wide spectrum of additional and diverse cortical abnormalities, including pachygyria, thickened cortex, lissencephaly, and polymicrogyria, which were traditionally thought to be distinct, suggesting they can have a unified underlying genetic causation.