While doctors do not fully understand what causes rheumatoid arthritis, they do know that having a family history of the disease increases a person's risk of developing it.
Rheumatoid arthritis (RA) is an autoimmune disorder in which a person's immune system attacks the fluid-filled linings of their joints. The result is inflammation and swelling that can cause pain, especially in the hand, wrist, and knee joints.
This article discusses the relationship between RA, genes, and a person's family history. We also look at additional risk factors for the disease.
Researchers believe that the cause of RA is often a combination of genetic and environmental factors.
For example, a study found that children who grew up with mothers who smoked had
However, doctors have not been able to correctly predict if a person with genetic risk factors for RA will or will not develop the disease.
Some researchers have said that this is because the large-scale population studies necessary to fully understand the genetics may not be economically feasible.
Researchers have identified more than 100 positions in the human DNA code that could relate to RA.
One example involves the human leukocyte antigen (HLA) genes. Doctors have pinpointed the HLA-DRB1 gene as having an association with RA.
According to the Arthritis Foundation, people who have this genetic marker are five times more likely to have RA than those who do not.
Other genes that may have an association with RA include:
- PTPN22: This gene plays a role in the development and progression of the disease.
- STAT4: This gene helps control how the body regulates and activates the immune system.
- TRAF1 and C5: These genes can cause chronic inflammation.
However, doctors have not identified how a person acquires these genes. It is possible that a parent could pass down an altered gene or that something external could modify a person's genes.
Also, not everyone who has RA-associated genes goes on to develop this condition.
In addition to a family history of RA, researchers have identified other risk factors, including:
- Age: Older adults are more likely to have RA.
- Sex: Women are more likely than men to develop this form of arthritis.
- Smoking: People who smoke are more likely to have RA, and their symptoms may be worse.
- Obesity: People with obesity have an increased risk.
- History of live births and breastfeeding: Women who have never given birth have a higher risk of developing RA. Women who have breastfed a baby have a decreased risk.
Anyone who is concerned about their risk of developing RA should talk to a doctor.
The doctor may recommend lifestyle changes to minimize specific risks. They may also explain the early signs and symptoms to look for to help catch and treat RA as soon as possible.
Some risk factors for RA are modifiable while others, such as age, are not.
However, a healthful lifestyle may help reduce the controllable risks of developing RA. Steps to take include:
- avoiding smoking and limiting secondhand exposure to cigarette smoke
- eating a nutritious diet
- exercising regularly
Research indicates that genetic risk factors are responsible for at least two-thirds of the risk of developing rheumatoid arthritis.
The genetic risk appears to be highest if a person has specific sequences of the HLA gene that research has identified as having an association with RA.
While having a family history of RA may increase a person's risk of getting this disease, so can a variety of lifestyle factors. By focusing on leading a healthful lifestyle, a person can reduce their risk.
Catching RA early and receiving prompt treatment can help slow the progression of the disease, so it is best to see a doctor as soon as possible for any joint pain or stiffness.