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Autoimmune conditions – such as autoimmune thyroiditis, psoriasis, rheumatoid arthritis, type 1 diabetes and more – are strongly influenced by genes. And while that doesn’t mean everyone with a similar genealogy will have the same autoimmune condition, it is one factor.
Researchers don’t know exactly what causes an autoimmune condition. Autoimmune conditions are considered to be polygenic (multifactorial) diseases. The main factors at play for whether someone is likely or unlikely to have an autoimmune disease are:
Some people have a genetic susceptibility to autoimmune conditions, and certain autoimmune diseases tend to run in families more than others.
A weakened or compromised immune system is often the trigger that provides the path for an autoimmune condition to surface.
Short-term or long-term exposure to certain environmental conditions or toxins can trigger a flare-up.
Most autoimmune conditions are chronic, meaning there may be many years while the condition is present but latent. When the symptoms are finally present enough to be clinically evident for diagnosis, the condition may then last for decades or a lifetime after diagnosis.
Is there a gene that causes autoimmunity?
The genetics of autoimmune conditions have been studied for years and researchers have concluded that there is no single autoimmune gene. Instead, numerous genes found throughout chromosomes in the genome have been shown to increase the risk of developing an autoimmune condition. The individual impact of a single gene is very small, so researchers theorize it’s a combination of several genes combined with a compromised immunity and environmental triggers that cause an autoimmune disease to surface.
Which autoimmune conditions are most related to your genes?
In a systematic review and meta-analysis of more than 60 articles and studies on familial autoimmunity, it was shown that certain autoimmune conditions tend to cluster in families more than others. The following conditions show the most evidence for having a strong gene and hereditary factor:
Autoimmune thyroiditis: Affects the thyroid, causing it to over- or under-produce hormones that control metabolism
Systemic lupus erythematosus: Affects many organs, including joints, kidneys, brain, heart and skin
Rheumatoid arthritis: Affects the joints
Celiac disease or gluten intolerance: Affects the gastrointestinal tract when gluten is ingested
Type 1 diabetes: Affects insulin-producing cells in the pancreas
Researchers and doctors have also noted that while some families have a predisposition to autoimmune conditions, it isn’t always the same disorders that get passed down. For example, a parent may have rheumatoid arthritis but their child may have celiac disease or no autoimmune condition at all. Remember, it’s not a single gene that causes an autoimmune disease. Rather, there are multiple factors at play, including a variety of genes and gene combinations, a compromised immunity, environmental triggers and time.