Is Pulmonary Fibrosis Hereditary?

In the case of pulmonary fibrosis patients, especially ones that are parents, a common concern is whether their condition is hereditary. Thankfully, most pulmonary fibrosis cases are considered sporadic, which means there’s no risk of passing the disease on to family members. There are, however, rare cases of what’s called familial idiopathic pulmonary fibrosis. Familial IPF is marked by multiple family members having abnormal genes associated with IPF.

What is Idiopathic Pulmonary Fibrosis?

There is no difference in symptoms when it comes to pulmonary fibrosis and idiopathic pulmonary fibrosis. “Idiopathic” is simply a term used when, after extensive testing, the presiding physician still cannot pinpoint the cause of the disease.

Idiopathic pulmonary fibrosis, like PF with known causes, is a disease in which the lungs develop scar tissue and lose their ability to function. To make a diagnosis of idiopathic pulmonary fibrosis, a physician will first conduct a battery of tests in an attempt to identify the cause of the disease.

If the disease is due to specific types of drugs (like those found in chemotherapy), radiation, environmental hypersensitivity (such as exposure to mold or animals), occupational hazards (such as exposure to coal dust or asbestos) or an autoimmune condition, the pulmonary fibrosis is not considered to be “idiopathic.” If, however, there is no plausible explanation for the disease, the diagnosis of IPF is made.

Idiopathic Pulmonary Fibrosis and Genetics

PF is usually considered to be familial when two or more members of the same family (either a parent, child, aunt/uncle or cousin) have been diagnosed with the disease. Most cases of familial IPF are autosomal dominant. This means that even if you inherit the abnormal gene from only one parent, you can still develop the disease.

Unfortunately, the genetics behind idiopathic pulmonary fibrosis are still poorly understood. Genetic testing is available for several genes but is not recommended due to poor clinical use. A few genes that may be responsible for inherited IPF are:

• Telomerase Genes: TERC genes provide information for making a single component of the telomerase enzyme. Telomerase are the custodians of structures called telomeres—repeated segments of DNA that are found at the ends of chromosomes.
• Surfactant Genes: These genes provide lubrication and allow for normal lung inflation, which is critical to normal lung function.
• Mucin Genes: Like surfactant genes, mucin genes also aid in the lubrication of lung tissue. They may also be involved in cell-cell signaling and help in preventing infection.

Can Pulmonary Fibrosis Be Prevented?

While pulmonary fibrosis with a distinct cause can be prevented by avoiding chemicals, particulates and dust, hereditary idiopathic pulmonary fibrosis cannot be circumvented. That said, if you are at risk for familial IPF, it’s imperative you limit your exposure to chemicals, drugs and environmental triggers that could exacerbate or trigger your IPF.

Some steps you can take to keep IPF at bay:

• Tell your doctor you have a history of familial IPF before taking any prescription drugs that affect the lungs, such as amiodarone, nitrofurantoin or methotrexate.
• Avoid radiation treatment, specifically to the chest. Opt for procedures like MRIs instead of CT scans.
• Be wary of moldy environments, and do not work near any airborne hazards like dust, fumes, vapors and fibers. If you cannot avoid these things, always wear a high-quality respirator. Change your clothes after being exposed to these types of triggers, as they can reside on your clothing long after you’ve left the area.
• Avoid exposure to caged birds. Pet birds can carry diseases that can be transmitted to their owners. These diseases occur via inhalation of contaminated materials such as bedding, and are particularly dangerous to those at risk of IPF as they have pulmonary-like symptoms. Disease transmitted by birds include influenza, Newcastle disease, Q fever, psittacosis, encephalitis and allergic alveolitis.
• Do not smoke. Smoking can trigger pulmonary fibrosis.
• Get your flu shot. While you may feel fine now, if you develop pneumonia or the flu, this can significantly exacerbate IPF. A pneumococcal shot to prevent pneumonia complications is also a great preventative step in maintaining optimal health.

Conclusion

While most pulmonary fibrosis is environmentally caused, some IPF is inherited. Several genes that seem to increase the risk of developing PF have been identified. Approximately 3-15 percent of patients who suffer from IPF have a family member who also has pulmonary fibrosis. That said, pulmonary fibrosis is a relatively rare condition. Approximately 130,000 people are affected in the United States, or 0.03 percent of the population. PF is more common in men and generally affects those above age 50.

There is no cure for pulmonary fibrosis. The damage caused to the lungs by scarring is permanent. Currently, existing treatments do not treat the disease as much as they slow lung scarring from developing and ease the symptoms for an improved quality of life. Systemic enzyme therapy may also break down fibrin that causes scarring in your lungs and help you breathe easier.  If you believe you are at risk of developing genetically linked pulmonary fibrosis, it’s important to avoid triggers to protect your health.