Is Psoriatic Arthritis Genetic?
The exact causes of psoriatic arthritis (PsA) are unknown. In PsA, the immune system attacks healthy joints and tissue. This can cause inflammation, swelling, and pain.
Environmental factors can play a role in this. Injury, infection, or exposure to other triggers can contribute to the inflammation that causes PsA symptoms.1 Researchers believe genetics may also increase the risk PsA in some people. Psoriatic diseases are known to run in families.1
How do genetics work?
People get their chromosomes, which contain the genes, from both parents. A chromosome is part of a person’s DNA. The DNA is what makes up the specific instructions for a person.2,3
When something is genetic, this means it was passed down to a person from members of his or her family. This can include parents, grandparents, and other blood relatives.2,3
What does it mean for a disease to be genetic?
Certain diseases are known to be passed down to people from family members who also have the disease. This means that if one parent has a gene mutation, or change, that causes a disease or makes the disease more likely to develop, they can pass this down to their children. These genes can be dominant or recessive.
A dominant gene means that if one parent has the disease or the genetic trait, their child has a 1 in 2 chance of also having this gene. A recessive gene needs to be passed down by both parents. Recessive genes may not cause the disease in either parent. Both parents can still pass the recessive gene to their children. If they do, the child has a 1 in 4 chance of also having the same gene mutation.2
What role do genetics have in psoriatic arthritis?
About 40 percent of people with PsA have at least one family member with psoriasis or psoriatic arthritis. However, that number is even higher for people who have a first-degree relative (sibling, parent, or child) with PsA.
About 55 percent of people with PsA have a first-degree relative who also has the disease. Because of this, doctors have always suspected that PsA could be a genetic disease. Scientific research is starting to prove this belief.4 Many recent studies have found there is strong evidence to suggest PsA is connected to gene mutation.
There is also evidence to suggest that the cause of psoriasis is related to genetics. Since we know that about 20 to 30 percent of people with psoriasis later go on to develop PsA, it stands to reason that genetics also plays a role in the worsening of disease.4-6
Future research on genetics and psoriatic arthritis
One of the main challenges is knowing which gene mutations specifically lead to PsA. Doctors also need to consider how other factors, like environmental causes, compare with genetic causes. Though studies are starting to confirm a link between genetics and PsA, more research is needed to understand the relationship.6
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