June 30th is World Pneumothorax Day and this year we are urging all doctors to ask about family history if a patient presents with a spontaneous pneumothorax. This one simple question can help to diagnose rare genetic conditions that cause pneumothorax and ultimately improve patient care.
What is a pneumothorax?
A pneumothorax (also known as a lung collapse) occurs when the air leaks from the lung causing it to collapse. Sometimes this happens spontaneously, and no cause is ever found. However, several rare genetic conditions can cause a pneumothorax.
What are the genetic causes of pneumothorax?
Birt-Hogg-Dubé syndrome (BHD) causes skin bumps, lung cysts, lung collapses and kidney cancer. It is caused by mutations in the folliculin gene and there is a 1 in 2 chance that your children will have BHD. The symptoms usually start in adulthood, with most people experiencing their first lung collapse between the ages of 20 and 30. The kidney cancer in BHD is normally slow growing. With regular kidney scans, it can be diagnosed, monitored and treated early.
Lymphangioleiomyomatosis (LAM) is a condition that affects the lungs, kidneys and lymphatic system. The most common symptom of LAM is a shortening of breath that gets worse over time and recurrent lung collapses. LAM almost exclusively occurs in women with most being diagnosed at 35 years old. LAM is caused by mutations in tuberous sclerosis genes. This genetic mutation is not inherited. Researchers believe it is a random change to the gene that happens in early development.
Marfan syndrome affects the body’s connective tissues which are a group of tissues that maintain the structure of the body. Symptoms vary between individuals but people with Marfan syndrome are often tall and slim and have flexible joints. Marfan syndrome can also affect heart, blood vessels and lungs with an increased risk of having a lung collapse. It is caused by a mutation in the fibrillin gene and there is 1 in 2 chance that the child of a parent with Marfan syndrome will inherit the syndrome.
Vascular Ehlers-Danlos syndrome (vEDS) affects the connective tissue in the body leading to fragile blood vessels and internal organs. People with vEDS often have thin skin and bruise easily. They are also at risk of hollow organs leaking which can result in a collapsed lung. vEDs is caused by a mutation in the COL3A1 gene. In most cases, vEDS is inherited from a parent. There is a 1 in 2 chance that children of people with vEDS will have vEDS.
Loeys-Dietz syndrome (LDS) is a genetic disorder of the connective tissue in the body. The condition affects bones, skin, eyes and the heart and blood vessels. It can also cause the lungs to collapse. There are five genetic causes of LDS with genetic mutations found in the TGFBR1, TGFBR2, SMAD3, TGFB2 and TGFB3 genes. Each child has a 1 in 2 chance of inheriting LDS.
Why is asking about family history important?
One in 10 people who have a spontaneous pneumothorax will have someone else in their family who has also had a lung collapse. Multiple cases of lung collapse in a family suggest that there may be a genetic cause. This is vital information that doctors can use to inform further tests and reach a diagnosis. As a lung collapse is often an early sign of a rare condition, it provides an opportunity for doctors to start treating and managing patients before other, sometimes more dangerous, symptoms occur.
We are urging all doctors to ask about family history if a patient presents with a lung collapse. This will lead to faster diagnosis of rare genetic conditions that are often missed.