PIK3CA and hemimegalencephaly: It was recently documented that postzygotic activating mutations in PIK3CA are present in several congenital malformation and overgrowth syndromes, including (but not limited to) congenital, lipomatous, overgrowth, vascular malformations, epidermal naevi and scoliosis (CLOVES) syndrome, fibroadipose hyperplasia, megalencephaly-capillary malformation syndrome, hemihyperplasia-multiple lipomatosis syndrome, hemimegalencephaly and facial infiltrating lipomatosis [16,17,18,19].