Prenatal Ultrasound and <scp>MRI</scp> in the Diagnosis of a Rare Fetal Dysplastic Megalencephaly Caused by <scp>AKT1</scp> Gene Variant

We report a prenatal case of rare dysplastic megalencephaly detected via ultrasound and magnetic resonance imaging (MRI), showing progressive macrocephaly and abnormal cortical development. Whole-exome sequencing (WES) identified a somatic AKT1 variant (c.49G>A), confirming the diagnosis. This case highlights the integration of imaging and genetic analysis in diagnosing fetal megalencephaly, underscoring the role of mTOR pathway disorders. Pregnancy was terminated after counseling.