Is Sleep Apnea Genetic?
Plenty has been written about the causes of obstructive sleep apnea (OSA).
For example, it’s caused by:
- Being overweight
- Having a thick neck (such as a fit bodybuilder)
- Overlarge tissues, like tonsils, blocking the airways
And the list goes on and on.
Drinking, smoking, and certain medications may also contribute to OSA, maybe not causing it, but certainly worsening a mild, undetected case.
But what about genetics? Might OSA run in families?
The short answer: Yes
While people can develop OSA for all these other reasons, the sad fact is that, for some families, it's a condition that's part of the gene pool.
Research going back as far as the 1990s and earlier confirms that OSA can occur in families. Not only that, but science has long known the risk for developing OSA increases along with increasing numbers of affected family members. These findings are independent of other factors like obesity or neck size. In other words, the more people in your family with an OSA diagnosis, the more likely you, too, will have it.1
The family connection can, quite literally, be seen by the naked eye. The shape of your cranium and lower jaw is a facial characteristic – clinically known as a facial phenotype — that runs in families. For instance, underdeveloped facial bones can cause the palate to arch too high or lead to a shallow jaw that slides back, creating obstructions in the airway while reclined during sleep.2
Family resemblance and risk for OSA
Research using MRI has also confirmed an increased risk for OSA related to larger volume of tissue in the tongue and throat, features that can be inherited within families.3
Think about it: many members within a family can resemble one another specifically because of the shapes of their faces. If they all share a problematic bone or tissue structure that makes OSA likely, then it just makes sense they’re likely to be at higher risk for it. This includes families of people of normal weight.4
Other shared traits beyond the upper anatomy include a propensity toward obesity, known to run in families. Common shared behaviors related to physical activity and eating habits may be part of the link between OSA and families.5
More than 30 percent of obese people also have an OSA diagnosis, and the numbers run even higher for those who are morbidly obese, at between 50 and 98 percent. Specifically, the way fat is deposited in the body — especially around the neck, tongue, and throat, or in abdominal accumulations — is what ties obesity to OSA.6
Many people are surprised to learn that some people are born with OSA. Infantile OSA occurs in children less than 12 months old and is typically caused by developmental impairment. More rarely, it is considered a familial disease, meaning it is linked by genetics.7
Genes associated with OSA
But beyond this, it’s known that there are several genes associated with OSA. These genes are linked to functions like breathing, tissue development, appetite, sleep-wake cycle, and inflammatory response.8
OSA is a heritable disease
Recent genetics investigations show that OSA is a heritable disease, meaning it runs in families. This research confirms that first-degree relatives of people with OSA (such as siblings or children) are about 50 percent more likely to snore or have observed apneas. 8,9
The science of gene discovery
Studies of twins and within families also show respiratory responsiveness, obesity, facial phenotypes to be significantly controlled by genetics (at a rate of between 30 and 70 percent). Genome-wide association studies (GWAS) for obesity have located 97 valid biomarkers linking it with OSA.9
More work is being conducted specifically on the new science of gene discovery for OSA. Researchers are gathering hundreds of thousands of samples of genome sequences to help determine genetic basis for OSA. In doing so, they hope to better grasp how OSA might happen within families and refine those therapies that might be most successful in treating it.9
Familial OSA is not out of your control
Despite the dreadful news that you likely have OSA because your brothers and sisters do, this doesn’t mean you do have it, it just means you are at higher risk for it.
To know for sure, talk to your doctor. They can screen you for risk factors and refer you to a sleep physician, who can run a clinical study to check for OSA. If you receive a diagnosis, then you can do yourself a favor and treat your condition.
Or, if you don’t receive a diagnosis, you can breathe a sigh of relief, even and especially in your sleep.
Do you feel stigmatized by sleep apnea?