Prenatal Phenotype of Common Arterial Trunk With Tricuspid Atresia and Bilateral Cleft Lip-Palate With Novel MASP1 Variant.

What is already known about this topic? ◦. 3 MC syndrome is a rare autosomal recessive disorder with limited prenatal reports. ◦. Cardiac anomalies are rarely described and only postnatally. What does this study add? ◦. First trimester prenatal suspicion of 3 MC syndrome confirmed by genetics and autopsy. ◦. Dual cardiac anomaly (common arterial trunk with tricuspid atresia) not previously described. ◦. Highlights persistent elbow flexion as a consistent prenatal finding. ◦. Expands the prenatal phenotype‐genotype spectrum with a novel homozygous MASP1 nonsense variant.