A Prenatal Ultrasound Study of Cerebral Cortical Sulci and Gyri Development in Fetuses With Overgrowth Syndrome and/or Cerebral Malformations due to Abnormalities in MTOR Pathway Genes

To investigate the abnormal development of cerebral cortical sulci and gyri in fetuses with Overgrowth Syndrome and/or Cerebral Malformations Due to mTOR Pathway Gene Abnormalities (OCMMPG), focusing on prenatal imaging correlates of mTOR dysregulation. Retrospective analysis of three OCMMPG cases diagnosed via whole-exome sequencing (WES). Sulco-gyral morphology was assessed using 2D cross-sectional imaging and 3D inversion Crystalvue/Realisticvue (3D-ICRV) rendering. Polymicrogyria (PMG) was identified in all cases via 2D and 3D-ICRV imaging. The third fetus exhibited a malformed Sylvian fissure and hypoplastic parieto-occipital sulcus (POS). 3D-ICRV revealed cortical thickening and microgyral fusion, aligning with PMG criteria. The integration of 2D imaging and 3D-ICRV technology enables comprehensive prenatal assessment of sulco-gyral development. Our findings highlight the utility of this approach in detecting mTOR-related cortical dysplasias, particularly in cases with atypical Sylvian fissure or POS hypoplasia.