WNK2 and Pleural effusion: RASopathies are heterogenous, overlapping disorders due to hyperactivating variants in the RAS/mitogen-activated protein kinase (MAPK) signaling cascade.36 RASopathy variants are a common etiology of hydrops and nuchal edema.29,30 In this study, CSFEs with RASopathy variants were all hydropic with pleural effusions and ascites and either with skin edema or polyhydramnios, similar to a recently described RASopathy cohort.39 CSFEs with VOUS in RASopathy genes also had hydrops and pleural effusions.