Hydrops, Arthrogryposis, and Cerebellar Hypoplasia in a Fetus With a de Novo BICD2 Variant: Expanding the Prenatal Phenotype of SMALED2B.

What is already known about this topic? ◦. BICD2 variants are associated with spinal muscular atrophy, lower extremity predominant type 2, typically diagnosed postnatally or after fetal demise. ◦. Prenatal presentations may include arthrogryposis multiplex congenita, hydrops, and fetal akinesia. What does this study add? ◦. This is the first report of a fetus with a prenatally detected BICD2 variant showing increased nuchal translucency and hydrops on first‐trimester ultrasound examination. ◦. This is also the first prenatal case in which cerebellar hypoplasia has been documented by ultrasound in a disease related to the BICD2 gene.