Bilateral Frontoparietal Polymicrogyria with Lissencephaly–Pachygyria Complex in Fraternal Twins due to Homozygous Non-sense Mutation in Exon 11 of ADGRG1 Gene: A Case Report

A bstract We present a case report with two 8-year-old fraternal twins who presented with myoclonic epilepsy and regression of milestones. Magnetic resonance imaging (MRI) of both cases revealed a near identical phenotype with bilateral frontoparietal polymicrogyria (BFPP) and lissencephaly–pachygyria complex, along with diffuse white matter changes and minute cerebellar cysts. Genetic testing revealed a non-sense mutation in the exon 11 of ADGRG1 gene (previously known as GPR56) responsible for neural migration. Previously reported cases describe identical twins with lissencephaly (LIS) on MRI. To our knowledge, this is the first case in which fraternal twins are seen to have this mutation and an imaging spectrum with both BFPP and LIS. We tend to highlight the classical imaging findings as well as a literature review of the cases in which twins were affected.