PMSE is caused by a homozygous deletion in the STE20-related kinase adaptorα (Strada) gene, a modulator of mTORC1 signaling via the AMP-activated protein kinase (AMPK)-TSC1/2 pathway (Puffenberger et al., 2007; Orlova et al., 2010). Here, STRADA is linked to polyhydramnios, megalencephaly, and symptomatic epilepsy.