Using the MME platform, we recognized consistent genotype-phenotype relationships among multiple families with polymicrogyria for 4 genes not previously associated with human disease: KIF26A, TMEM161B, PANX1, and MAN2C1. Phenotypic expansions of 2 known disease genes to include polymicrogyria are supported by multiple families within our cohort: SCN2A (3 families), associated with developmental and epileptic encephalopathy, and QRICH1 (4 families), associated with Ververi-Brady Syndrome. The gene discussed is SCN2A; the disease is developmental and epileptic encephalopathy.