BRAF and posterior cortical atrophy: The BRAFV600E mutation (8.9% pediatric and 9.75% adult PCA) and KIAA1549‐BRAF fusions (41.1% pediatric and 25.7% adult) are two alterations of the BRAF gene that demonstrate a variable pattern between different age‐groups in case of the majority circumscribed astrocytoma (PCAs).38