Prenatal Imaging of Micrognathia, Micromelia, and Fetal Hydrops Leading to the Diagnosis of Achondrogenesis Type II with a COL2A1 Missense Mutation.

This case report describes a fetus with achondrogenesis type II, a severe and lethal type II collagen disorder, presenting with micrognathia and hydrops. Prenatal evaluation with 2D/3D ultrasound, followed by postmortem imaging and pathological examination, confirmed the diagnosis. Genetic testing revealed a heterozygous COL2A1 mutation (1703G>A; Gly516Ser, exon 24). The significance of this study lies in the identification of a missense mutation in COL2A1 associated with achondrogenesis type II. This report highlights that the condition may present with hydrops and craniofacial anomalies, establishing this variant as a pathogenic mutation associated with the disorder.