Lung disease is the major cause of illness and death in individuals with osteogenesis imperfecta (OI), a collagen-related bone disorder. Previously, scoliosis and chest wall deformities were considered responsible for abnormal lung function in OI. We studied children and adults with several types of OI using lung function tests, X-Rays and lung CTs. Most patients had restrictive lung disease and decreased gas exchange, independent of scoliosis. Analysis of chest scans and breathing tests showed thickening of the walls of small airways and lung tissue abnormalities.  We conclude that OI also causes intrinsic lung disease that negatively impacts Quality of Life (QOL) in OI. Further study of intrinsic lung abnormalities may lead to improved treatment options and improve QOL. (By Dr. Joan Marini, https://jmg.bmj.com/content/early/2023/05/16/jmg-2022-109009 )