In both daughters, screening for early ILD was performed. For both, no history of respiratory symptoms was reported and physical examination was normal. Both had an active lifestyle including regular exercise, normal PFTs without restriction or decrement in diffusing capacity for carbon monoxide, and exercise oximetry that revealed no oxygen desaturation. In the older daughter (aged 43 years), high-resolution CT (HRCT) scan of the chest was normal. In the younger daughter (aged 39 years), who carried both the SFTPC mutation and the ABCA3 variation, HRCT scan demonstrated early interstitial thickening in a few peripheral areas in the lower lobes, findings possibly suggestive of early ILD (Fig 2). Given these HRCT scan findings, a bronchoscopy, with BAL and transbronchial biopsies, was performed. BAL was performed in the right middle lobe (RML), with predominance of monocytes/macrophages on lavage fluid cell count and differential. Biopsies were performed in the RML and right lower lobe. Evaluation of hematoxylin and eosin-stained sections from the biopsies revealed multiple foci where alveolar tissue was involved by interstitial fibrosis, including areas with dense scar and associated lymphoplasmacytic inflammation (Fig 3). A single fibroblastic focus was noted on one section. These histologic findings were observed in biopsies from the right lower lobe where mild HRCT scan abnormalities were detected as well as from the RML where the HRCT scan was completely normal. Electron microscopy images from the biopsies revealed bands of collagen deposition in the lung interstitium and type 2 AECs that had poorly developed lamellar bodies, fewer mature lamellar bodies, and the accumulation of numerous small cytoplasmic vesicles (Fig 4).