Systemic lupus erythematosus (SLE), also known as lupus, is an autoimmune disease that affects many different parts of the body. An autoimmune disease occurs when your immune system attacks healthy cells by mistake.
Diseases that can be passed down from parent to child are known as hereditary. Lupus, however, is not a hereditary condition — though genetic factors, along with environmental factors, appear to play a role. Researchers have identified many genes that may contribute to the development of lupus, but there doesn’t seem to be one gene that can be called a lupus gene.
The way lupus is inherited is currently unknown. You don’t directly inherit lupus from your parents, but you can inherit certain genes that make it more likely that you’ll develop the disease.
According to the Lupus Foundation of America, 20 percent of people with lupus also have a parent or sibling with the condition. Additionally, about 5 percent of children whose parents have lupus will also end up with the disease.
If you have a family member with lupus, you may have an increased risk of developing it yourself. However, some people with lupus have no family history of the disease.
You may know what symptoms to look for if you have a family member with lupus. A MyLupusTeam member shared, “I knew for several years that I had lupus. My mother did, so I knew the symptoms.”
Early recognition and treatment of lupus may help avoid damage and improve your health and quality of life.
Factors other than your family history can affect your susceptibility to lupus, such as:
Genome-wide association studies have helped scientists identify several genes associated with lupus. These studies involve scanning the DNA (genetic code) of a group of people to find similarities and differences in the genes of people with lupus. Researchers have identified more than 100 genes associated with lupus so far.
Genes can be found on chromosomes inside every cell in your body. They carry instructions for how your body should function and for your individual traits. When a gene is changed in a harmful way, it is called a mutation. Unsurprisingly, most of the genes associated with SLE are involved with the immune system.
The major histocompatibility complex (MHC) is a group of genes involved in recognizing the difference between your own cells and pathogens (foreign invaders such as bacteria and viruses). It was the first group of genes to be associated with SLE.
MHC genes contain the directions for making several different immune proteins. Specific changes in some of these proteins can increase your risk of developing SLE.
MHC genes carry directions for making human leukocyte antigens (HLAs), which are present on human cells as a signal to the immune system. Scientists have consistently found variations of certain HLAs (called alleles) associated with lupus.
People with some types of HLA alleles may have a two- to threefold increase in their risk of developing lupus. Associations with HLA alleles are generally inconsistent across ethnic groups.
MHC genes also encode the directions for making other immune proteins like cytokines (proteins produced by immune cells). MHC genes act as messengers, sending signals between cells to help regulate inflammation and complement proteins (specialized proteins that are part of the immune system). Cytokines, such as tumor necrosis factor-alpha (TNF-alpha), contribute to inflammation in lupus. Complement proteins that don’t properly identify pathogens have also been linked with the development of lupus.
Fc gamma receptors bind to immunoglobulin G (IgG) antibodies, which are responsible for binding pathogens. People with lupus are more likely to have genetic variants of Fc gamma receptors that don’t bind to IgG as well.
The programmed cell death 1 (PDCD1) gene is involved in cell apoptosis — the process of programmed cell death (a series of steps the body takes to eliminate unnecessary or abnormal cells). Researchers have found that in animals, getting rid of this gene leads to lupuslike symptoms. So far, results in humans have been inconsistent.
Research from 2022 shows that a gene called toll-like receptor 7 (TLR7) might play a key role in causing lupus. TLR7 is involved in activating the immune system.
Scientists found a specific mutation of TLR7 in a 7-year-old child with lupus. When they introduced this mutation into healthy mice, the mice developed lupus. So far, scientists have found this mutation in only one person, so more research is needed to see if it’s present in others with lupus. This discovery, which provides insight into why lupus develops in some people, may also lead to new treatment options.
Monogenic lupus is the result of a mutation in just one gene. In most cases, lupus is polygenic (caused by several genes).
There are several different genes that, when changed, can cause monogenic lupus. Some of the genes that can cause monogenic lupus control processes such as:
Evidence from studies on twins with lupus suggests that factors other than genes are involved in developing the condition. If genetics alone were responsible, the twin of a person diagnosed with lupus would have nearly a 100 percent chance of developing lupus. Instead, the chance that the twin will develop the condition is only 24 percent to 40 percent.
Epigenetics refers to how your behavior and the environment influence your gene expression (the way genes work). Epigenetic changes caused by your behavior can include smoking and diet. Environmental factors include exposure to chemicals, sunlight, or infections. Epigenetic changes may cause lupus by affecting T cells, cytokines, or other parts of the immune response.
Currently, there are no screening tests or genetic tests for lupus. The lack of available screening can be scary for parents who worry about passing lupus on to their children. A MyLupusTeam member commented, “I pray that my two daughters don’t inherit the genes of lupus. They are both in their 20s and so far, so good.”
However, just because a family member — even a parent or sibling — has lupus doesn’t mean you’ll also have it. If you’re concerned that you may have lupus because it runs in your family, it’s best to meet with a rheumatologist who can conduct a thorough evaluation. Although laboratory results may be helpful, lupus is a clinical diagnosis — the condition is identified based on a person’s signs and symptoms, their medical history, and a physical exam.
There is no way to prevent lupus, but you can manage your environmental risk factors. Take steps such as these:
If you have questions about any of your risk factors for lupus, be sure to discuss them with your doctor.
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