Is There An Asthma Gene
While asthma is genetic, environmental factors play a part too. Unlike other inherited conditions, there is no single gene for asthma. Neither is there a guarantee that youll develop it if your parents had it, as it can skip a generation. Genetic research has identified various asthma genes, or gene complexes, that play a strong role. These include DPP10, GRPA and SPINK5.
Genomics is the study of how your genes interact with the environment. Genomic research is ongoing and provides a valuable insight into the complexity of asthma and the various factors involved in its development. Environmental factors that can increase the risk of asthma occurring can be both indoor and outdoor. For example, being exposed to second-hand smoke, poor air quality, pollution, cold temperatures and high humidity can all increase your risk.
Research shows that a combination of several genes interacting with each other and with environmental factors can increase the likelihood of asthma.
Triggers Irritants And Allergens
Successful long-term control of asthma requires identifying environmental triggers, allergens, and irritants that increase symptoms or precipitate exacerbations. Because these factors are at least potentially modifiable, it is important to either remove or minimize them to reduce overall risk.
Education and abatement are essential prerequisites for convincing clients about the need for specific allergen avoidance. It is only possible to convince clients to undertake the abatement measures when they know what their triggers are.
Determination of sensitivity to a specific allergen is usually not possible through the clients medical history alone, but requires testing. Current recommendations for avoidance measures are allergen-specific and clients should be tested for sensitivity only to allergens they may be exposed to. Skin or in vitro tests educate clients about the role of allergens in their disease and are reliable in determining the presence of specific allergens. These tests, however, do not determine whether the specific immunoglobulin is responsible for the clients symptoms.
Warm-blooded animalsincluding pets and rodentsproduce dander, urine, feces, and saliva that can cause allergic reactions. Successful controlled trials of high animal dander concentrations and abatement have been reported for schools and homes in which no animal is present but where significant dander counts have been recorded.
Signs Symptoms And Complications
How often;signs;and;symptoms;of asthma occur may depend on how severe, or intense, the asthma is and whether you are exposed to allergens. Some people have symptoms every day, while others have symptoms only a few days of the year. For some people, asthma may cause discomfort but does not interfere with daily activities. If you have more severe asthma, however, your asthma may limit what you are able to do.
When asthma is well controlled, a person shows few symptoms. When symptoms worsen, a person can have what is called an asthma attack, or an exacerbation. Over time, uncontrolled asthma can damage the airways in the lungs.
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Mendelian And Classical Genetics
Modern genetics started with Mendel’s studies of the nature of inheritance in plants. In his paper “Versuche Ã¼ber Pflanzenhybriden” , presented in 1865 to the Naturforschender Verein in , Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically. Although this pattern of inheritance could only be observed for a few traits, Mendel’s work suggested that heredity was particulate, not acquired, and that the inheritance patterns of many traits could be explained through simple rules and ratios.
The importance of Mendel’s work did not gain wide understanding until 1900, after his death, when and other scientists rediscovered his research. , a proponent of Mendel’s work, coined the word genetics in 1905 . Bateson both acted as a mentor and was aided significantly by the work of other scientists from Newnham College at Cambridge, specifically the work of , , and . Bateson popularized the usage of the word genetics to describe the study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in in 1906.
Respiratory Viral And Bacterial Factors That Influence Early Childhood Asthma
- 1Division of Immunology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- 2Division of Immunology, Health Science Faculty, International Centre for Genetic Engineering and Biotechnology and Institute of Infectious Diseases and Molecular Medicine , University of Cape Town, Cape Town, South Africa
- 3Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa , Institute of Infectious Diseases and Molecular Medicine , University of Cape Town, Cape Town, South Africa
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Poor Lung Function At Early Age And The Development Of Asthma In Children
The period of 06 years is crucial, as it is during this phase that the majority of asthma cases are reported . Poor lung function at infancy has been identified as one of the predisposing factors of childhood-onset asthma . Wheezing in the first year of life is a key feature of impaired lung function resulting from respiratory infections which are recurrent during childhood . In a longitudinal study by Martinez et al. where they followed up children from birth till the age of 6 years, they reported that almost half of the children enrolled in the study had recurrent wheezing episodes by the time they reached age 6. They also presented with signs of diminished lung function . They further noted respiratory infection in lower airways by the age of 3 as the leading cause of wheezing which they associated with asthma predisposition. Over two decades later, a follow up study led by Tai et al. further reported wheezing at infancy as a risk factor for subsequent asthma development in adults who were followed up for 50 years . Considering that asthma in adolescence is linked to wheezing during the first 6 years of life and subsequent defective lung function, it is therefore within reason to infer that poor lung function in early life does not only predispose children to asthma development, but may be the reason behind disease severity in adults .
How Is Asthma In Children Diagnosed
Asthma is often difficult to diagnose in infants. However, the disease can often be diagnosed in older children based on the child’s medical history, symptoms, and physical examination, and on certain tests:
- Medical history and symptom description: The healthcare provider will ask about any history of breathing problems your child may have, as well as a family history of asthma, allergies, a skin condition called eczema, or other lung diseases. Be sure to describe your child’s symptoms in detail, including when and how often these symptoms have been occurring.
- Physical exam: During the physical examination, the doctor will listen to your child’s heart and lungs.
- Tests: Many children will have a chest X-ray and pulmonary function tests, which measure the amount of air in the lungs and how fast it can be exhaled . The results will help the provider determine how severe the asthma is. Children younger than 5 are usually unable to perform pulmonary function tests, so doctors rely heavily on history, symptoms, and physical examination in making the diagnosis.
The doctor may order other tests to help identify particular asthma triggers, including allergy skin testing and blood tests.
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Does Asthma Run In The Family
Asthma, a chronic lung condition that affects the airways, can occur in people of all ages. In some cases, asthma symptoms can be mild and are well controlled with asthma medications. For others, symptoms are more severe and can have a debilitating effect on daily life and work. Asthma and other atopic conditions can run in the family, meaning if you have a family history of the condition, you are more at risk to developing it.
Theres no cure for this bronchial condition, but it can be effectively managed with modern treatments, and research continues to reveal more about asthma causes.
Read on to discover if asthma is genetic or environmental and if theres any truth in the idea that asthma can run in families.
Exposure To Triggers At Work
Occupational asthma is a type of asthma caused by certain things found in the workplace, such as chemicals or dust from flour or wood.
If you havent had asthma before and then get it because of the work you do, and if your symptoms improve when youre not at work, you probably have occupational asthma.
Occupational asthma is a common cause of adult onset asthma.
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Asthma And Family History
Numerous studies have found that your family history can be a risk factor for the development of asthma. If one of your parents or siblings has asthma, then youre more likely to have it too. If both your parents have asthma, then this risk increases further. Youre also more likely to have other related atopic conditions, such as eczema, hay fever or food allergies.
This doesnt mean that youll definitely develop asthma if other members of your family have it, just that the genetics predispose you to a greater risk. Nor does it mean that you wont develop the condition if your relatives are all free of asthma.
Diagnosing Asthma In Children Younger Than 6
It can be hard to tell whether a child under age 6 has asthma or another respiratory condition, because young children often cannot perform a pulmonary function test such as spirometry. After checking a childs history and symptoms, the doctor may try asthma medicines for a few months to see how well a child responds. About 40% of children who wheeze when they get colds or respiratory infections are eventually diagnosed with asthma.
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What Makes A Child More Likely To Develop Asthma
There are many risk factors for developing childhood asthma. These include:
- Family history of asthma, allergies and atopy .
- Frequent respiratory infections.
- Being African American.
- Being raised in a low-income environment.
In children who are under five years of age, the most common cause of asthma symptoms is upper respiratory viral infections such as the common cold.
How Do You Give Your Child Asthma Medication
You will be giving your child asthma medications using a valved holding chamber device or a home nebulizer .
Your child may be able to use a metered dose inhaler with a VHC. A VHC is a chamber that attaches to the MDI and holds the burst of medication. Talk with your child’s provider to see if an MDI with VHC is right for your child.
The nebulizer delivers asthma medications by changing them from a liquid to a mist. Your child gets the medicine by breathing it in through a facemask or mouthpiece.
There are some asthma medications that are also breath-actuated, or come as a dry powder. These medications are given to older children who are able to demonstrate the appropriate technique for using them.
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Global Alliance Against Chronic Respiratory Diseases
The Global Alliance against Chronic Respiratory Diseases contributes to WHOs work to prevent and control chronic respiratory diseases. GARD is a voluntary alliance of national and international organizations and agencies from many countries committed to the vision of a world where all people breathe freely.
Association Between Viral Infections And Early Childhood Asthma
The association between viral infections and early childhood asthma is an area of research interest, and advances in virus detection methods such as more sensitive polymerase chain reaction have propelled early detection of different viral genotypes . Host genetics and other external environmental agents have been associated with asthma exacerbation in young children. Viral infections are thought to be the major triggers of asthma exacerbation, accounting for 8095% in children compared with 7580% in adults . Respiratory viral infections are important causative agents of many lower tract respiratory illnesses in early childhood ranging from wheezing episodes to more severe bronchiolitis which could lead to later development of asthma . Respiratory syncytial virus and rhinovirus are the most common and frequently detected viral exacerbation in newborns . Initially, RSV was thought to be a major etiologic agent of viral induced exacerbation, however, subsequent studies have shown that RV dominates after 12 months of life . Thus, this suggests that RSV is the major cause of exacerbation in the first year of life after which RV takes over .
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Risk Factors For The Development Of Asthma And Food Allergies
Webinar recorded on Thursday, June 24, 2021
There are many risk factors for the development of asthma and food allergies, involving complex interactions among multiple environmental exposures, immune regulation and genetic influences.; Join Dr. Angela Hogan as she helps us understand these factors and look at new treatments.
Causes Of Asthma: Your Guide To Asthma Risk Factors And Triggers
Asthma is a condition that causes your airways to swell and produce extra mucus making it difficult to breathe according to Jason Casselman D.O. with Reid Allergy. Symptoms of asthma include coughing wheezing and chest tightness. Asthma can affect anyone children and adults so its important to understand the causes of asthma and its symptoms.
Whos at risk of developing asthma?
While it can develop at any age most people with asthma begin to experience symptoms as children. According to the National Institutes of Health children who frequently wheeze and have airway infections are at the greatest risk of developing asthma after age six. In children girls are less likely to have asthma but as adults women are more likely than men. Adult-onset asthma is when people develop asthma symptoms when older.
Doctors and researchers are still working to understand and identify the causes of asthma in adults and children. The American Lung Association listed the following risk factors for developing asthma:
- Family history: Having a parent with asthma increases the likelihood that youll have it.
- Obesity: Overweight children and adults are at greater risk and have a more challenging time managing symptoms.
- Respiratory infections: Childhood viral airway infections increase risks.
- Environmental causes: Dust chemical fumes air pollution and mold can all cause asthma.
- Allergies: Eczema or hay fever play a role.
- Smoking: Both firsthand and secondhand smoke make it more likely.
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Less Common Asthma Triggers
Although these triggers are relatively uncommon, they are potentially serious for people who are senstitive to them.
- Medication: A number of different medications are associated with asthma, among them pain medications and beta blockers.
- Foods: Certain foods, including fish, soy, eggs, wheat, and tree nuts, are known to trigger asthma, especially in infants and children.
- Exercise: Wheezing, coughing, and chest pain that occur in response to physical activity, known as exercise-induced asthma , is thought to occur because people tend to breathe through their mouths during exercise, which sends cold, dry air to the lungs. .
Research For Your Health
The NHLBI is part of the U.S. Department of Health and Human Services National Institutes of Health the Nations biomedical;research;agency that makes important scientific discovery to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders, including asthma. Learn about the current and future NHLBI efforts to improve health through research and scientific discovery.
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Recombination And Genetic Linkage
The diploid nature of chromosomes allows for genes on different chromosomes to or be separated from their homologous pair during sexual reproduction wherein haploid gametes are formed. In this way new combinations of genes can occur in the offspring of a mating pair. Genes on the same chromosome would theoretically never recombine. However, they do, via the cellular process of . During crossover, chromosomes exchange stretches of DNA, effectively shuffling the gene alleles between the chromosomes. This process of chromosomal crossover generally occurs during , a series of cell divisions that creates haploid cells. , particularly in microbial , appears to serve the adaptive function of repair of DNA damages.
The first cytological demonstration of crossing over was performed by Harriet Creighton and in 1931. Their research and experiments on corn provided cytological evidence for the genetic theory that linked genes on paired chromosomes do in fact exchange places from one homolog to the other.
Genes generally their functional effect through the production of , which are complex molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each of which is composed of a sequence of , and the DNA sequence of a gene is used to produce a specific . This process begins with the production of an molecule with a sequence matching the gene’s DNA sequence, a process called .
Largest Asthma Genetics Study
The largest and most comprehensive study of asthma genetics to date was conducted in 2010 by a consortium of more than a hundred centres worldwide . They ran a GWA study , which genotyped 10,365 persons with asthma and 16,110 unaffected persons to test for association between 582,892 SNPs and asthma. This large study identified genes on chromosomes 2 , 6 , 9 , 15 , 17 , and 22 associated with asthma. The ORMDL3 gene, in particular, was associatedwith childhood onset, whereas the HLA-DQ gene was related to later-onset asthma. Further, the results showed that 38% of all cases of childhood-onset asthma were attributable to a combination of the identified genes.
The study also found an association between serum total IgE and the HLA-DRB1 gene within the class II region of the major histocompatibility complex on chromosome 6. However, this locus was not associated with asthma; most of the identified susceptibility loci for asthma were not associated with IgE, suggesting that elevation of serum total IgE has only a minor role in asthma development.
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