Can you inherit chronic fatigue syndrome from your parents?
Or, are fatigue/energy levels determined more by your environment than your genes?
Like most aspects of science, the truth lies somewhere between the two extremes. There is more to chronic fatigue syndrome then a bad set of genes. But the genes you get from mom and dad certainly contribute to the likelihood of you developing the disease. Before you go further in this article, be sure you read my previous article that outlines the foundational knowledge of genetics and their connection to chronic fatigue syndrome. Before we get into genetics, I need you to become familiar with a term called epigenetics.
Epigenetics and chronic fatigue syndrome
It is commonly thought that you’re stuck with the genes you received from your parents. While this reductionist thinking may help assuage your personal responsibility behind why you have a particular illness, it’s not entirely true. You are not born with concrete, un-alterable DNA. Even if everyone in your maternal line had chronic fatigue syndrome, that does mean you’re destined for a life of CFS.
Genes are not set in stone. They are able to be expressed or suppressed based on the way you interact with your environment. Consider the following experiment to better illustrate my point: (1)
The agouti mouse has a specific gene, which is the reason for the mouse’s yellow fur and its obesity. This particular gene is passed onto future generations through reproduction, and therefore so are the agouti mouse’s traits. Hence, all agouti mice will have yellow fur and be obese. The common assumption is that since the agouti mouse has the “obesity gene” all future generations will be obese.
However, there are aspects in the environment that can cause a gene to not be expressed. One of these mechanisms is called methylation. It can cause a gene to be supressed (or expressed) without altering the underlying DNA. In the case of agouti mice, the researchers took two groups of agouti mothers. One group was given methyl-rich supplements (think high quality B-vitamins); the other was given nothing.
The offspring of the agouti mice that had not been given anything produced typical agouti offspring – yellow fur and obese. The offspring of the agouti mice that took the methyl-rich suplements and underwent methylation created a dramatic effect in their appearance! These mice had a normal brown coat, and were very lean. They looked nothing like agouti mice. Even though they inherited the same agouti genes.
For those of you with chronic fatigue syndrome, mom and dad may be responsible for setting you up with genes that predispose you to develop the illness. However, something in your environment is turning the chronic fatigue genes “on”.
Genes and chronic fatigue syndrome: what’s the connection?
Studies have shown that chronic fatigue has an inheritable or genetic component. (2) If your mom, dad, brother, or, sister suffers from chronic fatigue, you have a higher risk of developing the disease. If your cousin or either grandparent has chronic fatigue syndrome, you’re also at an elevated risk (when compared to the general public) though not at as high of a risk as with a first-degree relative like mom or dad. (3, 4)
There have been studies done on twins with chronic fatigue syndrome. Researchers found that fraternal twins were less likely to develop chronic fatigue syndrome than identical twins. Fraternal twins have different DNA. Whereas identical twins share exactly the same DNA and genes. These studies done on twins conclusively show that chronic fatigue has at least some genetic component to the development of the disease. (5)
Have you heard of the human leukocyte antigen (HLA) complex?
Probably not. But the human leukocyte antigen is an integral part of the regulation of your immune system. (6) If your HLA complex if not functioning properly, your body will struggle to differentiate itself from foreign invaders like viral and bacterial infections.
In 98% of those with celiac disease, the HLA DQ II and/or HLA DQ VIII complexes are active. You would think that this would make celiac disease entirely a genetic illness. But these complexes are also active in ~50% of the population without celiac disease. (7) This illustrates that celiac disease has a genetic component but is not caused entirely by genetics.
Here lies the similarity between celiac disease and chronic fatigue syndrome. And perhaps this is why the two conditions are linked. In chronic fatigue syndrome, instead of HLA DQ II or VIII activation (like in celiac disease), there is an increase in antigens to HLA DQA1 and the HLA DR4. (8) The HLA-DQA1 gene provides instructions for making a protein that plays a critical role in your immune system.
These human leukocyte antigens (HLA) types are inherited from your parents. While we still have lots to learn, those with HLA antigens are more likely to develop autoimmune diseases and/or chronic fatigue syndrome. (9) This is likely why autoimmune diseases and chronic fatigue syndrome are connected.
What happens when you get sick?
Well, if you’re a relatively healthy person, your body would begin producing something called cytokines. Cytokines are a group of proteins released by your immune system in response to an infection.
New research suggests that those with chronic fatigue syndrome have significantly higher levels of circulating cytokines in response to infection(s). This abnormal response is thought to be due to a genetic abnormality. (10) At the time of this writing, we’re not sure why this occurs. But it could help to explain why those with chronic fatigue feel sick. Their body is reacting as though it is fighting an infection.
What triggers the chronic fatigue genes?
At the time of this writing, there are no conclusive findings. But we do have a number of sound theories. I’ll explore each of them in more detail below.
Your microbiome is the collection of bacteria found inside your digestive tract, skin, nose etc. These bacterial colonies are absolutely essential to your health and well-being. In fact, these small bacteria can alter how you digest food, your immune system, and even the progression of disease(es).
Different species of bacteria can turn on (or off) inflammatory signals which in turn alter your body’s DNA. This is the epigenetic variable I discussed earlier in this post about the agouti mice.
Research in this realm is just beginning, but it is thought that we will soon be able to identify what type(s) of bacteria make up a gut with irritable bowel syndrome. Or, a gut with Crohn’s disease. We’ll then also (hopefully) know what bacterial colonies make up a healthy gut.
You likely won’t be surprised to hear that those with chronic fatigue syndrome are thought to have very different microbiomes than healthy controls. (11) In fact, CFS sufferers have microbiomes that closely resemble those with IBS. (12) This is why optimizing your gut health is an essential part of treatment for anyone with chronic fatigue syndrome.
Childhood illness(es) and/or trauma
It is estimated that nearly half of the population in the United States has experienced some form of childhood trauma (13) and that more than thirty percent of children experience a chronic illness before the age of eighteen. (14) Both illness and trauma have been shown to be able to alter your genetics.
One study done in the Philippines tracked the blood from over 500 participants dating back to the early 1980s. In 2005, the same blood was again used to analyze 114 genes associated with immune processes that regulate inflammation.
The methylation of nine of those genes was found to have a close relationship with a number of childhood variables including household socioeconomic status in childhood, extended absence of a parent in childhood, whether the individual was breastfed, and even whether the child was exposed to animal feces.
This study opened the eyes of researchers. By simply identifying specific childhood experiences, it was possible to (accurately) predict if an inflammatory gene would be turned on or off. (15) In other words, by identifying certain childhood experiences, it was possible for the researchers to predict whether one or more of those nine inflammation genes would be on or off.
Those with chronic fatigue syndrome often report significantly elevated incidents of childhood trauma. In fact, childhood trauma increases the risk for developing chronic fatigue syndrome by nearly six times. (16) It is thought that trauma experienced early in life decreases salivary cortisol levels. (17)
Remember, low cortisol levels are one of the diagnostic features of adrenal fatigue.
The HLA genes associated with chronic fatigue syndrome are the same genes associated with celiac disease and other autoimmune illnesses. (18) For those readers familiar with my blog, you’ll know that food is a common trigger for the autoimmune process. While there may not be much research done on the connection between food and chronic fatigue, I can report that from clinical experience, food allergies or sensitivities are always involved.
Food has the ability to alter your genes. Consider the following example:
During the winter of 1944–1945, the Netherlands suffered a terrible famine as a result of the German occupation, and the population’s nutritional intake dropped to fewer than 1000 calories per day. Women continued to conceive and give birth during these hard times, and these children are now adults in their sixties.
Recent studies have revealed that these individuals – exposed to calorie restrictions while in their mother’s uterus – have a higher rate of chronic conditions such as diabetes, cardiovascular disease, and obesity than their siblings. The first months of pregnancy seem to have had the greatest effect on disease risk.
It is thought that the caloric scarcity caused epigenetic changes in the fetus’s DNA. These children’s genes adapted to be born into a time when calories were scarce. Fortunately, conditions improved for those born during the Dutch hunger famine. They now have access to all the calories they could ever want.
Unfortunately, their DNA was altered to be very frugal with calorie consumption. The famine in which they were conceived altered their genes to be better able to survive on very low calories. When these individuals consume high-calorie diets, they are more likely to develop the above illnesses because of the genetic “adaptation”.
I’m confident all readers can agree that stress contributes to illness. Not surprisingly, those with chronic fatigue syndrome report to have higher levels of cumulative life stress. (19) Stress as you likely describe it relates to common life stressors – finances, relationships, work, or family tension.
These certainly contribute, no doubt. However, there are more insidious forms of stress that are more likely to bring about epigenetic changes. These “hidden’ stressors occur below the surface. They often happen without your conscious awareness surrounding them.
The more common hidden stresses include:
- Blood Sugar abnormalities
- Chronically high, low, or imbalanced blood sugar produces a tremendous stress on your body.
- Poor sleep hygiene
- Sleeping less than 7-8 hours each night, traveling across multiple time zones, or sleep disorders create a build-up of stress forceful enough to alter your genes.
- Hidden sources of inflammation
- This includes eating foods you’re allergic/sensitive to, bacterial or parasitic infections in your digestive tract, or undiagnosed inflammatory conditions.
New research has shown chronic stress to alter the DNA of mice. (20) It is thought that the long-term excretion (and exposure) of adrenaline (which is released when your body is exposed to stress) causes DNA damage and even premature aging. (21)
Remember, your body cannot tell the difference between types of stress(es). The stress from a blood sugar irregularity releases a very similar cascade of hormones to a stressful drive home in a winter snowstorm. Should these stress hormones be released over the long-term, the likelihood of DNA damage rises.
Ok, now you know the genetic connection to chronic fatigue syndrome!
Remember, it’s your environment that determines whether your gene(s) will be turned on or off. You are not destined to develop CFS.
It’s time for me to hear from you!
What environmental factors have you found to improve your chronic fatigue symptoms?
Want to know more than your doctor about chronic fatigue?
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Also published on Medium.