Primary spontaneous pneumothorax (Primary spontaneous pneumothorax) - Gen FLCN  

Primary spontaneous pneumothorax is a disorder characterized by abnormal accumulation of air in the pleural space, which can cause partial or complete collapse of a lung. This type of pneumothorax is considered primary, because it occurs in the absence of pulmonary disease such as emphysema. Primary spontaneous pneumothorax due to the formation of small air spaces in the lung tissue that are broken, causing air leakage into the pleural space. The air in the pleural space creates pressure on the lung and can collapse it . A person with this disorder may feel chest pain on the side of the collapsed lung and respiratory distress. Air vesicles may be in one or both lungs for a long period of time before breaking. Certain factors such as changes in atmospheric pressure, or a sudden deep breathing, can cause rupture of a vesicle with consequent air outlet into the pleural space. Often people who develop a primary spontaneous pneumothorax have no previous signs of illness, because the vesicles by themselves do not cause any symptoms and are only visible in imaging methods.

This process is due to mutations in the gene FLCN (folliculin), located on the short arm of chromosome 17 (17p11.2), encoding the protein foliculina. In the lungs, it folliculin found in connective tissue cells and allows the lungs expand and contract with breathing. Folliculin also occurs in the cells lining the alveoli. This protein would help control the growth and division of cells, may play a role in lung tissue recovery after damage.

They have identified at least eight mutations in the gene FLCN in individuals with primary spontaneous pneumothorax. Many of these mutations cause the synthesis of an abnormally short, nonfunctional protein foliculina. The link between abnormal foliculina and the appearance of vesicles could be the existence of an inflammatory process in lung tissue that could alter and damage tissue, resulting in vesicles.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to cause disease. In most cases, a person inherits the gene FLCN mutation from an affected parent. People who have a genetic mutation associated vesicles appear to develop, but it is estimated that only 40 percent of them go on to develop a primary spontaneous pneumothorax. In addition, some gene mutations acquired during the lifetime of a person and are present only in certain cells. These changes, called somatic mutations, not inherited. Causing mutations of primary spontaneous pneumothorax, may be somatic mutations, not inherited, sometimes associated with various types of non - hereditary sporadic tumors. Somatic mutations in the gene FLCN found in some cases of carcinoma renal clear cell and in some colon cancers. These mutations may change the structure of the protein foliculina altering its tumor suppressor function.  

Tests in IVAMI: in IVAMI perform detection of mutations associated with primary spontaneous pneumothorax, by complete PCR amplification of exons FLCN gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).