Somatic and/or germline variants in numerous PI3K–AKT–mTOR pathway genes, including TSC2, TSC1, MTOR, PIK3CA, AKT3, RHEB, DEPDC5, NPRL3 and NPRL2, are known to be associated with malformations within the FCD–hemimegalencephaly spectrum55,135–139. Here, TSC1 is linked to fleck corneal dystrophy.