Prenatal Presentation of Congenital Alveolar Capillary Dysplasia With Misalignment of Pulmonary Veins: A Case Initially Suspected as Posterior Urethral Valves.

Alveolar capillary dysplasia with misalignment of the pulmonary veins (ACDMPV) is a rare, typically lethal pulmonary disorder characterized by underdeveloped pulmonary vascularization. It usually presents within the first 48 h of life with progressive respiratory distress and therapy-resistant persistent pulmonary hypertension of the newborn (PPHN). ACDMPV is associated with genomic alterations at the FOXF1 locus, with most cases arising de novo. We present a case in which suspected urethral valves, managed prenatally with fetal vesicoamniotic shunting, were the first indication of ACDMPV. In our patient, we discovered a previously unreported FOXF1 frameshift variant, c.203dupG (p.Leu69Profs226). This case expands the spectrum of pathogenic FOXF1 variants and illustrates the diagnostic challenges posed by an atypical prenatal presentation of ACDMPV. It underscores the importance of considering ACDMPV in the differential diagnosis of fetal urinary tract anomalies, particularly when additional fetal abnormalities are identified.