Is Asthma Genetic?

In this article, we’ll explain whether asthma is linked to genetics and how likely it is to be passed down through families [1]. We’ll look at the role of genetics, including whether having a family history of asthma means you’ll develop it yourself. We’ll also cover common environmental triggers that can contribute to asthma symptoms and how this is associated with genetic risk. We’ll also look at early-onset asthma, including how and why the condition might begin during childhood.

Key Takeaways

Here are the five biggest takeaways from this article about whether asthma is genetic:

• Research has confirmed that asthma can be inherited, with specific genetic markers linked to an increased risk.

• Asthma is influenced by several genes rather than one. These genes can affect the immune system, lung development and how the body responds to environmental triggers.

• Having asthma-related genes increases your likelihood of developing the condition, but it’s not a certainty.

• Common asthma triggers include allergens, air pollution, second-hand smoke, viral infections, cold air and emotional stress.

• Early-onset asthma is frequently seen in children with a family history of asthma or allergies.

The genetic factors that can contribute to asthma:

Genetic Predisposition

It is well known that asthma often runs in families. In 1989, researchers discovered one of the first known genetic links to a lung condition. This discovery helped confirm that asthma can be inherited [2].

Genes are passed down from our parents and influence how our bodies grow, function and respond to the environment. In the 1989 study, scientists looked at the genetic code of several families with a history of asthma. They identified a specific genetic marker on chromosome 11 that was linked to an increased risk of developing allergic asthma. 85% of people who carried this marker were more likely to experience asthma symptoms.

It should be noted, however, that genetics alone does not cause asthma. Environmental factors such as pollution, tobacco smoke and respiratory infections can also affect how likely someone is to develop asthma, even if they also have a genetic predisposition.

Combined effect of multiple genes

While specific genes have been identified as increasing the risk of asthma, research shows that the condition is not usually caused by a single gene. Instead, asthma is known as a complex genetic disorder, meaning it develops due to the influence of multiple genes [3]. Each gene may only have a small effect on its own, but when combined, they can significantly increase the risk of developing asthma.

These genes can affect how the immune system responds to allergens, how the lungs develop and function and how the body reacts to triggers like pollen, dust mites, or air pollution. People may have different combinations of genetic variants, which could be why asthma can vary so much from person to person.

Some genetic variants only seem to increase asthma risk when they occur alongside specific environmental factors or other genes [4]. This makes it difficult to predict who will go on to develop asthma, even if they have a family history of the condition.

Does a generic predisposition for asthma guarantee that you will develop it?

Having a genetic predisposition to asthma means you may be more likely to develop the condition, but it does not guarantee that you will. Many people carry genetic markers linked to asthma, yet never develop symptoms. This is because genes are only one factor that could cause asthma. Environmental factors can also play a significant role.

Exposure to things like air pollution, tobacco smoke, allergens, viral infections and changes in weather can all influence whether someone with a genetic tendency actually develops asthma.

While genetics can increase the risk, they do not determine your likelihood on their own.

Environmental asthma triggers

Even if someone has a genetic predisposition to asthma, it’s often environmental triggers that can cause symptoms. These triggers can vary from person to person, but a few are more common than others.

Exposure to allergens

One of the most common environmental triggers is exposure to allergens. These include:

• Pollen

• Dust mites

• Mould spores

• Animal dander

For people with asthma, coming into contact with these substances can cause inflammation in the airways, leading to coughing, wheezing and difficulty breathing [5].

Air pollution

Air pollution is another major factor. Outdoor pollutants, often produced by traffic and industrial activity, have been linked to increased asthma symptoms and attacks [6] [7]. Indoor air pollution, such as fumes from cleaning products, second-hand smoke and poor ventilation, can also be harmful [8].

Viral respiratory infections, particularly in early childhood, are also recognised as environmental risk factors. The common cold or flu can increase inflammation in the airways and may trigger or worsen asthma symptoms, especially in people who are already genetically susceptible [9] [10].

Other factors such as cold air, exercise, emotional stress and changes in weather can also act as triggers for some people. These don’t cause asthma on their own, but they can make symptoms worse.

Early-Onset Asthma (starting in childhood)

Asthma often begins in childhood, and this early-onset is strongly linked to genetic factors. Children with a family history of asthma, allergies, or other related conditions are more likely to develop asthma themselves. According to NHS Genomics Education, specific genetic variants can affect how a child’s immune system develops and how their airways respond to allergens and irritants [1].

Early-onset asthma is commonly associated with allergic conditions such as eczema or hay fever, which may appear before asthma symptoms develop. These children may show signs of wheezing, coughing, or breathlessness from a young age, particularly when they have a cold or are exposed to environmental triggers like pollen, dust, or pet hair.

Although genetics plays a key role, the environment is also important. Factors such as exposure to cigarette smoke, viral infections in early childhood and air pollution can all contribute to the development and severity of asthma in children.

Final Thoughts

Asthma is a complex condition influenced by both genetics and the environment. While having a genetic predisposition can increase the risk of developing asthma, it does not mean a person will definitely experience symptoms. 

Multiple genes are often involved, each playing a small role, and these genetic factors often interact with environmental triggers such as allergens, pollution, viral infections and lifestyle factors. Early-onset asthma, which begins in childhood, is linked to inherited traits but can also be worsened by exposure to harmful substances in the environment. 

Understanding the combined effect of genetics and environmental factors is essential for recognising risk, improving early diagnosis and managing the condition effectively.

At UK Meds, we provide a number of different asthma medications to help manage the condition regardless of its root cause. 

Sources

[1] Asthma and the genome - Genomics Education

[2] Unlocking the secrets of asthma: how we discovered the first genetic link - Asthma + Lung UK

[3] Asthma - Genes and Disease - NCBI Bookshelf

[4] Genetics of asthma: an introduction for the clinician - PMC

[5] Gene-Environment Interactions in Asthma: Genetic and Epigenetic Effects - PubMed

[6] Decoding the genetic and epigenetic basis of asthma - Stikker - 2023 - Allergy - Wiley Online Library

[7] Interactions between genes and environmental factors in asthma and atopy: new developments | Respiratory Research

[8] Asthma Triggers - Medical Glossary | UK Meds

[9] Allergic Asthma: Influence of Genetic and Environmental Factors - PMC

[10] CME review article Genetic, epigenetic, and environmental factors in asthma and allergy - Science Direct