Masked ABCA3-Related Interstitial Lung Disease in a Neonate With Prenatally Diagnosed Total Anomalous Pulmonary Venous Connection.

Obstructive total anomalous pulmonary venous connection (TAPVC) and ABCA3-related interstitial lung disease (ILD) rarely coexist. We report a neonate with TAPVC complicated by compound heterozygous ABCA3 variants (c.4180dup/p.V1394fs maternal, c.3446A>G/p.D1149G paternal). Overlapping neonatal respiratory symptoms mask the underlying surfactant disorder, easily causing misdiagnosis and delayed targeted management. This case highlights that the genetic screening for ABCA3 deficiency is mandatory for infants with persistent severe hypoxemia and ventilator dependence after complete TAPVC surgical repair. To our knowledge, this is the first documented co-occurrence of TAPVC and congenital ABCA3-related ILD.