SNP Shot: Genomic Insights

Primary spontaneous pneumothorax (PSP) happens when air abnormally collects in the pleural space, the area between the lungs and the chest wall. This air buildup can cause a lung to partially or completely collapse. It's called "primary" because it occurs in people without underlying lung diseases like emphysema. The term "spontaneous" indicates the condition wasn't triggered by an injury, such as a broken rib. PSP is thought to be caused by small air-filled sacs called blebs that develop in the lung tissue and then burst. When a bleb ruptures, air leaks into the pleural space, putting pressure on the lung and leading to its collapse. Symptoms of PSP can include chest pain on the side of the affected lung and difficulty breathing.

Blebs can exist on the lung(s) for a significant period without causing problems. The rupture of a bleb can be triggered by various factors, including changes in air pressure or a sudden, deep inhalation. Often, individuals experiencing PSP are otherwise healthy and unaware of any issues before the event. Blebs themselves usually don't cause symptoms and are only detectable through medical imaging. Individuals can have anywhere from one to over thirty blebs. After a bleb ruptures and causes a pneumothorax, the likelihood of recurrence ranges from approximately 13 to 60 percent.

Inheritance:

When PSP is caused by mutations in the FLCN gene, it follows an autosomal dominant inheritance pattern. This means that having just one copy of the mutated gene in each cell is enough to cause the condition. Typically, the FLCN gene mutation is inherited from a parent who also carries the mutation. Individuals with FLCN gene mutations linked to PSP seem to invariably develop blebs. However, it's estimated that only about 40 percent of these individuals will actually experience a primary spontaneous pneumothorax.