This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Primary spontaneous pneumothorax is an abnormal accumulation of air in the pleural space (the space between the lungs and the chest cavity) that can result in the partial or complete collapse of a lung. It is called primary because it occurs in the absence of lung disease such as emphysema and spontaneous because the pneumothhorax was not caused by an injury such as a rib fracture. Primary spontaneous pneumothorax is likely caused by the formation of small sacs of air (blebs) in lung tissue that rupture, causing air to leak into the pleural space. This air creates pressure on the lung and can lead to its collapse. Symptoms may include chest pain on the side of the collapsed lung and shortness of breath. The blebs that lead to primary spontaneous pneumothorax may be present in an individual’s lung (or lungs) for a long time before they rupture. A change in air pressure or a very sudden deep breath may cause a rupture to occur. In most cases, there are no prior signs of illness. Once a bleb ruptures and causes a pneumothorax, rates for recurrence may be as high as 13 to 60 percent. Many researchers believe that genetic factors may play a role in the development of primary spontaneous pneumothorax. In rare cases, the condition can be caused by mutations in the FLCN gene. In these cases, the condition follows an autosomal dominant pattern of inheritance. In addition, several genetic disorders have been linked to primary spontaneous pneumothorax, including Marfan syndrome, homocystinuria, and Birt-Hogg-Dube syndrome.
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