Previous studies of FCDII cohorts have noted associations between the causative gene and the malformation size, such as the predominance of somatic MTOR mutations in bottom of sulcus dysplasia, and PIK3CA and AKT3 variants in HME.14,18,49 It is unclear some people with mTORopathies present with IESS compared with others in whom focal epilepsies occur, despite sharing the same genetic causes. Here, PIK3CA is linked to infantile spasms.