Asthma and Genetics: What Is the Connection?
Asthma affects both children and adults. It is one of the most common long-term diseases in children.
Asthma has a strong genetic component, meaning it runs in families. A child who has one parent with asthma has a 25% risk of developing asthma, while the risk is around 50% if both parents have asthma.
This article explores the role that genetics play in asthma, types of asthma, and asthma symptoms and treatments.
Asthma is known to run in families. The risk of developing asthma due to genetic factors, sometimes called heritability, ranges from 35–70%. Another study suggests heritability might be close to 90% for children who develop asthma.
Asthma is not caused by a mutation in one particular gene. However, it can be caused by multiple genes interacting with each other as well as with environmental factors.
This combination makes it difficult for researchers to predict whether someone will develop asthma.
If one or both of your parents has asthma, you may or may not develop it. However, there is no guarantee that you will. The opposite is also true: even if neither of your parents has asthma, you may still develop asthma later in life.
Is there an asthma gene?
There is no single gene that causes asthma. Instead, asthma develops based on the interaction of a variety of genes with each other and with the environment. Your individual risk of developing asthma is determined by:
- your genes
- the types of environmental exposures you experience
- the timing of the environmental exposures
Environmental factors that may influence asthma include:
- exposure to air pollution
- exposure to tobacco smoke
- viral infections as a young child
- exposure to dust mites and other environmental allergens
- exposure to mold
- experience being a person who is overweight or a person with obesity
- urbanization, which may introduce lifestyle factors that contribute to asthma
Asthma is a chronic disease that affects the lungs. When the immune system reacts to a trigger, it causes inflammation in the airways. This leads to wheezing, coughing, tightness in your chest, and breathlessness.
The different types of asthma include:
- adult-onset asthma
- exercise-induced asthma
- occupational asthma
- nonallergic asthma
- allergic asthma
- asthma-chronic obstructive pulmonary disease (COPD) overlap
- pediatric asthma
Genetics are likely to play a larger role in asthma that begins in childhood, while environmental factors are responsible for types of adult-onset asthma, including asthma associated with COPD and occupational asthma.
Asthma occurs when the immune system reacts to something in the lungs. Environmental factors that can cause an asthma attack are often called triggers.
Asthma triggers vary from person to person. If you have asthma, knowing your asthma triggers can help you avoid flare-ups. When triggers are unavoidable, you can be alert for signs of an asthma attack and carry out your rescue treatment plan.
Some common triggers of asthma include:
- tobacco smoke — from smoking or from secondhand smoke
- dust mites
- outdoor air pollution
- waste from pests like cockroaches, mice, or rats
- cleaning products, disinfectants, or chemicals
- infections related to colds, the flu, or respiratory syncytial virus
- breathing cold air
- intense exercise
Asthma is very common. According to the Centers for Disease Control and Prevention (CDC), more than 20 million adults and more than 5 million children in the United States have asthma. That is one in 13 people.
Some risk factors for asthma include:
- family history of asthma
- exposure to secondhand smoke — when your birth parent was pregnant with you or when you were a child
- exposure to chemical or industrial dust in the workplace
- experience being a person with obesity
- history of allergies
- history of respiratory viruses as a child
When asthma occurs in childhood, it is more common in boys. In teens and adults, asthma is more common in females.
Race and ethnicity may be factors in whether you develop asthma as well. In the U.S., asthma occurs more frequently in Black American, African American, and Puerto Rican people than in people from other races or ethnic groups.
Asthma symptoms vary, and they can range from mild to severe. Common symptoms include:
- a persistent cough (often at night)
- shortness of breath
- wheezing (a whistling or rattling sound when you breathe)
- tightness in the chest
Treatments for asthma focus on avoiding triggers when possible and taking medications to manage the condition.
The first step in managing your asthma is knowing your triggers and avoiding them when possible. For example, if pollen triggers your asthma, you might shower and wash your face when you come inside after a day with a high pollen count, or you could keep your windows closed during pollen season.
In addition to avoiding triggers, there are two types of medicine that can help you manage your asthma: long-term control medication and quick-relief medication.
Long-term control medications are medications you take on a daily basis. They help you manage symptoms with the goal of avoiding an asthma attack.
Quick-relief or rescue medications are meant for use during an asthma attack. During an asthma attack, symptoms become more severe and can even be life threatening.
Frequent asthma attacks may be a sign you need to work with your doctor to adjust your treatment plan.
Asthma is a common yet complex disease that can develop due to interactions between genetic and environmental factors. Asthma can run in families. Having a parent or parents with asthma can increase your risk of developing the condition. However, not all people with risk factors will develop asthma.
Asthma that begins in childhood is likely to have a stronger genetic component than adult-onset asthma.
If you have asthma, you can control it by taking medicine and avoiding the environmental elements that can trigger an attack. Treatment plans typically include medication for long-term asthma control taken daily and quick-relief medication for an asthma attack. If your symptoms worsen, you and your doctor can work together to make changes to your asthma management plan.