Abstract
OBJECTIVE: This study aims to elucidate two distinct fetal ultrasound features associated with aberrant brain sulcus formation as potential prenatal markers for Sotos syndrome caused by mutations in the NSD1 gene. METHOD: This retrospective study investigated three fetuses across two pregnancies, including a pair of monochorionic diamniotic twins, all diagnosed with Sotos syndrome via whole exome sequencing (WES). Comprehensive clinical and laboratory data were collected and analyzed. Each fetus underwent a series of specialized neurosonographic assessments to evaluate the development of the cerebral cortex. RESULTS: All three fetuses exhibited aberrant brain sulcus formation characterized by Sylvian fissure (SF) abnormalities and shallow parietooccipital sulcus (POS). WES revealed the presence of two de novo NSD1 variants in these fetuses. CONCLUSIONS: Fetal aberrant brain sulcus formation may represent a distinctive ultrasound feature indicative of Sotos syndrome, thereby offering additional diagnostic insights for the identification of this condition.