Abstract
RATIONALE: Neuroendocrine cell hyperplasia of infancy (NEHI) is a diffuse lung disease that presents in infancy and improves during childhood. Long-term outcomes have not previously been described. In one familial cohort, we have reported that NEHI is associated with a heterozygous variant of NKX2.1/TTF1. OBJECTIVES: Our objective was to determine whether pulmonary abnormalities persist in adults with NEHI, to aid in elucidating the natural history of this disease. METHODS: Four adult relatives with heterozygous NKX2.1 mutation and with clinical histories compatible with NEHI enrolled in a prospective study that included questionnaires, pulmonary function tests, and chest computed tomography scans. MEASUREMENTS AND MAIN RESULTS: Mild radiologic abnormalities including mosaicism were seen in all four cases. Three individuals had obstruction on pulmonary function tests, two had marked air trapping, and three had symptomatic impairments with exercise intolerance. CONCLUSIONS: Although clinical improvement occurs over time, NEHI may result in lifelong pulmonary abnormalities in some cases. Further studies are required to better describe the natural history of this disease and would be facilitated by additional delineation of genetic mechanisms to enable improved case identification.