Chest CT scan of a person with type III osteogenesis imperfecta, showing bony chest wall deformities and lungs with focal emphysema (black arrow) and ground glass opacities (black circles).
Lung disease is the leading cause of illness and death for people with osteogenesis imperfecta (OI), a group of rare genetic bone fragility disorders that affect the structure or quantity of the protein collagen. Most cases of OI are caused by mutations in the genes that provide instructions for type 1 collagen, the major protein component of bone. Type 1 collagen helps make bones strong but also is a component of lung tissue.
Lung problems in people with OI may result from a combination of factors. Scoliosis—a sideways curvature of the spine—and deformities in the chest wall may make it more difficult for the lungs to expand. Previously, NICHD researchers found that lung function declines with age even among children with OI who do not have scoliosis, suggesting the contribution of additional factors involving the lung tissue itself.
Recent work by a collaborative clinical team led by Joan Marini, M.D., Ph.D., provides new insights into the origin, progression, and characteristics of lung disease in children and young adults with OI. Researchers administered lung function tests to 37 children and young adults with OI, of whom 29 had mutations in the genes for type 1 collagen. Study participants also received X-rays and computed tomography (CT) scans of the chest.
Regardless of whether they had scoliosis, most participants had restrictive lung disease—a decrease in the total volume of air that the lungs can hold—and reduced gas exchange—a disruption of oxygen and carbon dioxide exchange in the lung tissues. The investigators also observed thickening of the walls of small airways and reduced airflow through them.
Further study may lead to improved treatment options and better quality of life for people with OI-related lung disease.
Learn more about the Bone and Matrix Biology in Development and Disease group: https://www.nichd.nih.gov/about/org/dir/affinity-groups/BMBDD