TSC1 and subependymal giant cell astrocytoma: Mutations in either the TSC1 or TSC2 genes, through the hamartin/tuberin complex and mTOR pathway, cause neuronal/interneuronal disruption, which in turn leads to a malformation of brain cortical migration and layering, which is reflected by the development of cortical tubers, white matter anomalies, subependymal nodules (and related subependymal giant cell astrocytoma), and brain cysts [71].