Genetics of Autoimmune Diseases: Are You Doomed Just Because You Have the Wrong Genes?
People have a lot of misconceptions about genetics and autoimmune disease. When someone gets diagnosed with a disease like lupus, rheumatoid arthritis, Hashimoto’s, or even type 1 diabetes, conventional medicine doctors in particular will tell their patients, “Oh, it’s just genetics.” So a lot of people assume: “It’s my genetics. I can’t do anything about it.” But just because you have a genetic risk for autoimmune disease, does that really mean that you’re destined to develop it?
I will give you the good news right away. Just because you are genetically predisposed to develop an autoimmune disease, doesn’t mean you will. Although you can’t control your genetics, you can control your lifestyle, diet, and, to a certain extent, your environment.
There’s a saying that “genetics load the gun, but lifestyle pulls the trigger.” The key is to address those lifestyle, dietary, and environmental factors that serve as the trigger for your autoimmune disease.
In this blog post, I’m going to address the genetics of autoimmune diseases, the genes associated with autoimmune diseases, and what you can do to stop your risk of developing one of these diseases or making it worse.
How Do Genes and Gene Mutations Influence My Health?
Deoxyribonucleic acid (DNA) makes up the genetic blueprint that codes for every cell, protein, and molecule in your body. Base pairs act as the building blocks for this genetic code. When these base pairs get switched or changed, it can cause a mutation or variation. This genetic difference can change how your proteins, chemicals, or cells function. Genes can also be turned on or off. When they’re turned on, it can impact your health in either a good or bad way. Likewise, when genes are turned off, it can affect your health. We will touch on this when we talk about epigenetics later. Remember, genes are just codes. Just because you have a gene doesn’t mean it’s creating a problem. Now that we have brushed up on our genetics, let’s talk about different autoimmune conditions and how genetics can play into them.
Is Rheumatoid Arthritis a Genetic Disease?
There is no gene for autoimmune diseases in general. However, specific types of autoimmune conditions are linked to genetic variations. For example, is rheumatoid arthritis genetic? The answer is yes. People who have certain genetic markers have a small increased risk of developing rheumatoid arthritis, usually in combination with environmental triggers. These genes include:
• STAT4
• TRAF1/C5
• PTPN22
The STAT4 gene switches on the immune system and regulates its functions. STAT4 mutations also play a role in other autoimmune conditions such as lupus. Chronic inflammation is linked to TRAF1/C5 genes. In Caucasians, the PTPN22 gene controls immune cell responses, playing a role in the development and progression of RA. It’s one of the most common genes blamed for RA risk.
Another gene that’s commonly linked to rheumatoid arthritis is HLA-DR4 (human leukocyte antigen). The HLA gene expresses its gene products on the surface of white blood cells, which can impact immunity. People who have the HLA-DR4 gene variation are more likely to develop rheumatoid arthritis compared to people who don’t have the variation. In addition, genetic markers for RA can determine how well someone responds to therapy.
Genetic Lupus
If you’re wondering “is lupus hereditary,” scientists know that some gene variations are associated with systemic lupus erythematosus. This makes sense, because it runs in some families. Research shows that you have an increased risk of developing lupus if a family member has the disease. However, most lupus cases are sporadic, meaning no other relative has the disease. An estimated 30 different genes can make a person more susceptible to lupus. The increased risk of lupus in people of African, Asian, Pacific Island, Hispanic/Latino, Native American, or Native Hawaiian descent points to a possible genetic risk among those groups.
Is Crohn’s Inherited?
A lot of people wonder “Is Crohn’s genetic?” Scientists have found at least 200 genetic variations involved in Crohn’s disease risk, including variations in these genes that play a role in immune system function:
- ATG16L1
- NOD2
- IL23R
- IRGM
They help the immune system mount a proper response to bacteria in the intestinal lining. Variations in these genes can cause the immune system to respond inappropriately to bacteria in the intestines. This can lead to inflammation and digestion-related problems associated with Crohn’s.
Is Ulcerative Colitis Genetic?
What about ulcerative colitis? Is UC genetic? The answer is that people with certain gene variations do have an increased risk of ulcerative colitis. In fact, having a family history of this disease is one of the biggest risk factors. Research suggests there are more than 70 genes that can make a person more susceptible to developing an inflammatory bowel disease like ulcerative colitis. Many of these genes are also linked to other autoimmune diseases like psoriasis and ankylosing spondylitis.
Many of the genetic culprits behind UC involve the proteins that make up the protective barrier of the lining of the intestines. When that barrier is weak, bacteria and toxins can spill out of the intestines into the systemic circulation, causing an immune system response.
Some genes involved in ulcerative colitis risk impact the function of T cells, immune cells that identify and attack foreign invaders. Variations in certain genes can cause T cells to attack beneficial bacteria in the intestines. Another possibility is that those genes can become too active in responding to foreign invaders in the colon, leading to an overactive immune response that plays a role in ulcerative colitis.
Are You Doomed to Get an Autoimmune Disease?
The good news? You can leverage your genetic insight to prevent autoimmune flare-ups or stop the disease from developing in the first place. If you know you have a genetic risk, you can make lifestyle changes in order to reduce environmental triggers. If you have poor genetics, you can be more preventative and keep an eye on your diet, lifestyle, and things you have control over in order to make sure your body can function optimally even with the genetic risk.
A lot of times what might seem like genetics is actually other lifestyle factors that people in your family share. Lupus and Hashimoto’s have a strong familial pattern, which could be related to genetics or lifestyle. People are like, “Yeah, but everyone in my family has it.” Yet, even if many people in a certain family have a particular disease, it’s not just their genes they have in common. They also usually live in similar environments, have similar lifestyles, and eat similar diets. So there’s a lot more to it than autoimmune family members that have the same genes. In some cases, a person develops an autoimmune condition because of all these other factors that they probably have in common with family members, like similar diets and environment.
Learning your potential triggers are important. Even something like how you manage stress could serve as a trigger. The goal is to consider all of your different triggers to prevent your genetics from causing problems for you, whether that involves stopping the disease from developing in the first place, or stopping it from progressing.
The Gut Microbiome and Genetics
The gut microbiome, the collection of bacteria and microorganisms that are found in your intestinal tract, also can influence your genes and autoimmunity. Stool testing looks for the presence of different DNA of different species in our microbiome. The microbes in our microbiome outnumber our human cells about 10 to one, so as you can imagine, they play a large role in genetics.
The Gene-Environment Interaction: Epigenetics
What you’re exposed to in the environment can lead to gene variations that promote the development of autoimmune disease or its progression. Examples of environmental triggers include toxins, chemicals, the diet, stress, and infections. These type of triggers are called epigenetic changes.
Your lifestyle and environment can produce epigenetic changes in your body that make you vulnerable to diseases, including autoimmune disease. Epigenetics refers to factors that influence your gene expression rather than the genetic code itself. Exposure to toxins, stress, nutrient deficiencies, and other environmental and lifestyle factors can lead to these type of changes. A lot of these epigenetic changes lead to modifications in the gut microbiota that can impact your health.
Epigenetic changes not only affect you, but they can also impact your children and grandchildren. There are several types of epigenetic changes, but one of the ones that we’re often concerned about is DNA methylation, which acts like a switch that turns a gene on or off.
Nutrigenomics in Genetics
Nutrigenomics is the role that diet plays in gene expression. Nutrigenomics refers to how your nutrient levels and nutrient deficiencies can play a role in what genes are expressed. For example, during World War II, during the winter of 1944-45, the Germans blocked food transport. This led to famine and deficiency in vitamins and proteins, especially in pregnant women. Down the line, scientists conducted studies to show how the famine affected offspring. They found that people born around the time of the famine were more vulnerable to conditions like schizophrenia, sensitivity to stress, and obesity. This illustrates the important role that nutrition plays in genetic vulnerability to disease.
Helping You Overcome Your Genetic Risk
As a functional medicine doctor, I can help you address your autoimmune disease even if you’re genetically predisposed to it, either by suppressing the development of the disease to begin with, or stop it from getting worse.
The first step? Schedule a free 15-minute discovery consultation, by phone or video. If you come on board as a practice member, I’ll order testing and conduct a history in order to determine your triggers. The bottom line? Don’t feel trapped by your genetic code. By reducing the environmental and lifestyle triggers, you can optimize your genes and reduce symptoms of autoimmune disease.
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