Is There a Connection Between Genetics and Asthma?
As a preemie, a lot of things in my life have been linked to predisposed genetic connections. There are lots of connections between genetics and asthma that are being discovered.
An overview of a recent genetic study
A recent study in The Lancet concluded a large investigative study that examined the genetic risk factors in both childhood and adult-onset asthma. I was really excited to see what they learned. The study was a genome-wide association study.1 In this study, they identify childhood-onset as those with onset younger than 12 years of age. Adult-onset was defined as a disease that developed between the ages of 26-65.
You may be asking yourself, what is a genome-wide association study? It is a process that rapidly scans markers across complex sets of DNA, or genomes, of a large group of people, to find genetic variations related to a specific disease. When genetic connections are identified, researchers use those to better identify strategies to detect, treat, and prevent the disease.2
The study highlighted the following key findings:
- Three times the genes are connected to childhood asthma than adult-onset asthma
- The cells in childhood asthma are greatly expressed in epithelial, blood and small intestine
- Adult-onset asthma cells tend to be in the lung, blood, small intestine, and spleen
- Adult-onset genes can be considered as a group of childhood genes1
Who knew that they were a subset of the same genes?
Potential connection between genetics and asthma
The study notes that the same type of gene, but with different processes, may lead to childhood asthma. The defects are found to be in the epithelial cell integrity and have been connected to other diseases that are seen in childhood. Other diseases include eczema and food allergies.
A "locus," or plural "loci," identifies the location of a particular gene on a chromosome. In the case of this study, the researchers were able to identify 28 locations that have not previously been documented. Seventeen were significant for childhood-onset only, but only one was significant for adult-onset asthma.1
These developments will help clinicians and investigators to determine strategies for detection and diagnosis. I am sure that these will lead to further development of phenotypes, endotypes, and the increase in personalized medicine treatments.
Reflecting on my own diagnosis
This week I needed to confirm some data in my medical records. I was looking through my pediatric records and I found a few mentions of asthma, but almost nothing about connections to genes or my preemie status. When I was discussing this with my parents, they mentioned that the doctors said that asthma is super common in children -- and not much else. I would love to see more research in the diagnosis of children with both asthma and bronchiolitis, as distinguishing between the two can be challenging. An interesting note was that areas of atelectasis (partial collapse of lung, lobe) can be caused by deflated airways or airways that are filled with fluid.3
In adulthood, I have had an issue with atelectasis and I wonder if there are genetic predispositions with this particular feature. While not necessarily a feature of asthma, it is something that can get tangled up in it. As it is related to mucus plugs and mucous production, which is a feature of asthma. This is a huge issue for me as there are very limited treatments for mucus hypersecretion.
What about your genetics?
Have you participated in research that looked at your genetic disposition towards asthma? I would love to hear about your experiences in the comments below.
What has your experience with Singulair been like?