The Role of Genetics in Chronic Lung Disease

Medically reviewed by Elaine K. Luo, MD on February 23, 2017Written by Colleen Story

idiopathic pulmonary fibrosis

Chronic lung disease remains incurable in most cases. Treatments help slow the progression of the disease and ease symptoms. People who develop the disease, though, usually have to live with it the rest of their lives.

Scientists hope to change that. So far, they’ve found that certain genes seem to be involved in many lung conditions. If they can zero in on exactly which ones have the largest impact, they may be able to better predict who’s at risk.

Even more importantly, they may be able to use that information to improve screening, diagnosis, and treatment.

What is chronic lung disease?

A chronic lung disease is any disease that damages your lungs and affects their function. The term encompasses a number of related conditions, including the following:

  • chronic obstructive pulmonary disease (COPD)
  • idiopathic pulmonary fibrosis (IPF) or other type of interstitial lung disease
  • chronic bronchitis
  • cystic fibrosis
  • emphysema
  • sarcoidosis
  • bronchiectasis
  • pneumonia
  • lung cancer

Also called chronic respiratory conditions, these diseases damage lungs to the point that it’s difficult to breathe. Some of them affect the small air sacs. Others damage the breathing tubes (bronchial tubes) or interstitium, which supports the air sacs. Still others cause scarring and stiffening.

There are significant differences in all these diseases. One thing they share, though, is that they can lead to lung damage that reduces quality of life. Scientists have focused on each individually in the hopes of discovering new treatments. But finding out how certain genes may be involved could provide even more hope for improved survival.

What really causes chronic lung disease?

It’s difficult in many cases to find out just what causes a person to develop lung disease. Risk factors include smoking, exposure to environmental toxins, and certain viral infections. But one person may develop a viral infection and go on to enjoy healthy lungs, while another develops lung disease. Scientists still aren’t sure why that is.

Smoking is considered the primary risk factor. Yet only about of smokers develop chronic obstructive pulmonary disease (COPD). Scientists wanted to discover what would make those people particularly vulnerable to the disease.

Turns out that genetics may play a much bigger role than thought. Genetics is the study of how certain traits are passed on from parents to their children. For example, your genes control your eye color, your height, and your facial features.

Genetic information exists inside each cell of your body. The Human Genome Project estimates that humans have between 20,000 and 25,000 genes. A small number of these are unique. These unique genes are responsible for the unique traits in each individual.

Certain genes can be passed on from parent to child that may increase risk of lung disease.

Many genes may increase risk of lung disease

Research hasn’t revealed a clear-cut relationship between genes and lung disease. It’s thought that certain genes could be associated with lung function, however.

After studying genes and lung health in over 7,600 people, found one specific gene variant that was strongly associated with impaired lung function. They looked at the relationship again in over 800 people, and found the same results.

Other studies have focused on different genes. For instance, scientists connected the SERPINE2 gene to COPD in a 2006 study published in the . In , researchers linked lung function with a number of gene variants. They added that genetics affected lung function regardless of other risk factors, like smoking.

In 2016, researchers published an showing genetic connections with several lung conditions. Asthma, for example, was associated with common variants of seven genes. Still different genes were linked with COPD, IPF, and sarcoidosis.

How might genetics influence future treatments?

Determining which genes may increase risk of genetic disease opens up new possibilities in diagnosis and treatment. As well, focusing in on which genes may influence lung disease can help give doctors new clues as to who may be at risk.

For example, alpha-1 antitrypsin deficiency (A1AT) has been linked with COPD. A 2011 study published in the reported that this genetic condition increases risk of early-onset emphysema, a form of COPD.

Now, a simple blood test can diagnose A1AT deficiency. People who test low for it may undergo additional tests that show what type of faulty gene they have. With that information, doctors may be able to determine how serious a person’s risk for lung disease might be.

As another example, a recent demonstrated a potential treatment for IPF. About 25 percent of people with IPF have two copies of a gene variant called TOLLIP. For these people, an inexpensive drug called N-acetyl cysteine significantly reduced the risk of hospitalization and death.

For the other 75 percent of people with the disease, though, the drug made the disease worse. That means more research needs to be done before this type of treatment could be recommended. Yet these types of results point the way to a promising future for people with chronic lung disease.

What you can do now

With a few exceptions, general genetic testing currently isn’t recommended. The research isn’t far enough along yet to say that this gene or that gene will increase your risk for a certain type of lung disease. From what’s been seen so far, there may be many genes involved.

Your best approach at this point is to refer to your family history. If your parents, siblings, or grandparents had a lung disease, your risk for that same disease is likely higher than someone who has no relatives with the disease.

Talk to your doctor. In certain cases, genetic testing may be helpful. They may refer you to a genetic counselor who can confirm diagnosis of A1AT deficiency, for example.

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