About 10% of the population of Europe and the US have chronic sinus infections, known as sinusitis or rhinosinusitis. While most everyone has known the occasional sinus pain from having a head cold, for some people, this problem continues for months at a time.
This article looks at the genetic reasons driving some people to have chronic sinus infections.
Members: Jump over to the Enhanced Member’s Version of this article to see your genetic data included.
Doctors define chronic rhino-sinusitis as having inflamed sinuses (stuffiness, nasal discharge, and changes in the ability to smell) for 12 weeks or more. For a lot of people, this can start with allergies or cold that turns into a sinus infection that lingers on, never really clearing up and flaring up again periodically.
Chronic sinus infections often go hand in hand with allergic rhinitis, frequent colds, atopic dermatitis, and asthma. [ref]
Your nose is constantly bringing in bacteria, fungi, and viruses. The first line of defense here is the mucous membrane and cilia that clear out the particles that come into the nose. In someone with chronic sinus infections, the can be persistent inflammation and biofilm formation in the sinus cavities. [ref] In most people though, the acute infection from a pathogen isn’t what is continuing to cause chronic sinus problems (defined as 12+ weeks). Instead, the inflammation in the sinuses continues after a triggering episode (allergies, fungus, pathogen, etc).[ref]
Genetics plays a role in the likelihood of having chronic sinus problems. The genetic component can range from genes that influence your inflammatory response to the mutations that cause cystic fibrosis or ciliary diseases. [ref]
When researchers investigate how genetics influences the risk of a condition, such as chronic sinus infections, they can go at this a couple of ways.
First, they can investigate whether specific genetic variants or mutations are found more commonly in people with the condition. For example, researchers can look at people who carry one copy of the mutations that cause cystic fibrosis to see if they are linked to sinus infections. Or they can investigate genes related to the immune response.
Another way to go about looking at genetic connections is to do a ‘genome-wide association study’. These research studies involve looking at the whole genome of a large number of people and seeing if there is anything that is different about people with a certain condition. Lots of computing power needed for these studies!
Bitter taste receptors have been shown in a number of genome-wide studies to be linked to the susceptibility to chronic sinus infections. While you may be thinking – taste receptors in your nose? – researchers have found that the taste receptors are found throughout the body and perform different functions. In your mouth, taste receptors are chemosensors that are abundant in taste bud cells. But in the nasal and sinus cavities, these same receptors are thought to detect secreted bacterial products and modulate the immune response. [ref]
The TAS2R38 gene codes for a bitter taste receptor. A fairly common variant in this gene causes some people to be unable to taste certain bitter flavors. This drives food preferences, to some extent, for things like bitter vegetables, coffee, and scotch. In the airways, though, it is thought that the TAS2R receptors are important for sensing certain gram-negative bacteria including Pseudomonas aeruginosa, a multi-drug resistant pathogen.[ref]
When the TAS2R38 receptor is activated in the nasal passages, it causes the secretion of nitric oxide. The increase in nitric oxide causes two things to happen: first, it increases the movement of cilia in the nose and second, it can directly kill bacteria.[ref]
Nasal polyps are a risk factor for chronic sinus infections. A genetic variant that causes the ALOX15 gene not to function is associated with a greatly decreased risk of both nasal polyps and chronic sinus infections. ALOX15 gene codes for an enzyme that is important in the metabolism of polyunsaturated fats. It is also important in the inflammatory response to certain pathogens, including pathogens that cause periodontal disease, peritonitis, sepsis, and atherosclerosis. [ref]
Cystic fibrosis is a genetic disease that causes an alteration to the thickness of mucous in the lungs, gut, and nasal passages. One complication of cystic fibrosis is chronic sinus infections, including with the drug-resistant P. aeruginosa. This is a big problem for people with cystic fibrosis because the pathogen can spread from the nose to the lungs, causing serious lung infections. [ref]
Alpha-1 antitrypsin deficiency is another genetic disease that is linked with an increased risk of chronic sinus infections. Mutations in the SERPINA1 gene cause alterations to the alpha-1 antitrypsin enzyme, which is active in the lungs at all times, but is also part of the immune response against infections. People with Alpha-1 antitrypsin deficiency are at a greater risk for chronic rhinosinusitis. [ref]
Inflammatory response, both to pathogens and overall inflammation, is also implicated in chronic sinus infections. While many inflammatory cytokine related genetic variants have been investigated, few of the studies have been replicated in more than one population group. The TNF-alpha variants, though, have been found in several studies to increase the risk of chronic sinus infections. The TNF gene codes for tumor necrosis factor-alpha, which is a major player in the regulation of immune cells.
TAS2R38 Gene: codes for a bitter taste receptor
Check your genetic data for rs10246939 (23andMe v4, v5; AncestryDNA):
Check your genetic data for rs713598 (23andMe v.4 and v.5; AncestryDNA):
NOS1 gene: codes for nitric oxide synthase 1, which helps to kill bacteria in the nose.
Check your genetic data for rs9658281 (23andMe v4; AncestryDNA):
ALOX15 gene: codes for an enzyme important in the metabolism of polyunsaturated fats and modulation of the immune response.
Check your genetic data for rs34210653 (23andMe v4, v5):
IL1RL1 gene: codes for the interleukin-1 receptor which is important in the immune response
Check your genetic data for rs13431828 (AncestryDNA):
SERPINA1 gene: codes for alpha-1 antitrypsin
Check your genetic data for rs1243168 (23andMe v4, v5):
TNF gene: codes for TNF-alpha, which regulates immune response
Check your genetic data for rs1800629 308G>A (23andMe v4, v5; AncestryDNA):
Cystic Fibrosis: Check out the article on carrier status for genetic diseases.
Alpha-1 Antitrypsin Deficiency: Check out the article on the alpha-1 antitrypsin deficiency mutations.
Many studies show that nasal irrigation statistically improves chronic sinus infections. There are several ways to do sinus irrigations, including using a neti pot. Make sure to only use distilled water for your saline rinse. [ref][ref][ref]
One study found that a 0.08% diluted povidone-iodine solution reduced sinus infection symptoms in patients with ‘recalcitrant’ infections.[ref] Look for a package for sinus rinse or a prepared solution labeled for sinus infections. Povidone-iodine is also called betadine.
Nitric oxide is produced in the nasal cavities and can kill fungus, viruses, and bacteria. Humming has been shown to increase nitric oxide in the nasal cavities. One case study found that humming at a low pitch for an hour or more for four days lessened chronic rhinosinusitis after one day with remission after 4 days.[ref] Another study found that nasal nitric oxide increased 15-fold during humming. [ref](I have no idea if this would work for other people, but it is free and easy to do…)
Hypoxia, or low oxygen, has also been shown to increase nitric oxide. [ref] This could be accomplished by breathing out through your nose and then holding the nose shut for as long as it is comfortable. Then inhaling in through the nose.
A triple-blind placebo-controlled clinical trial found that 4,000 IU of vitamin D per day decreased the severity of nasal polyps. [ref]
Steam was shown in a study to help in the short term with sinus headaches, but it didn’t improve outcomes with chronic sinusitis. [ref]