Genetics plays an important role in understanding Sjögren’s, but it is only one piece of a much larger puzzle. Genes act as the body’s instruction manual, guiding how cells function and influencing everything from physical traits to how the immune system behaves. While all humans share roughly 22,000 genes, small variations between individuals help explain why some people are more vulnerable to certain diseases, including Sjögren’s.
Unlike conditions caused by a single gene, Sjögren’s is considered a complex genetic disease. This means that no single gene is responsible for causing it. Instead, multiple genes contribute to a person’s risk, along with environmental factors such as infections, hormonal influences, and possibly other triggers. As a result, the condition does not follow a clear pattern of inheritance within families, and having a genetic predisposition does not guarantee that someone will develop the disease.
Researchers have identified several important genetic links to Sjögren’s, particularly within the human leukocyte antigen (HLA) system. These genes, located on chromosome 6, are essential for helping the immune system distinguish between the body’s own cells and foreign invaders. Certain variations in HLA genes—especially HLA-DQ and HLA-DR—are more commonly found in people with Sjögren’s, suggesting they play a role in increasing susceptibility. Other genes, such as STAT4 and IRF5, have also been associated with the disease and are involved in regulating immune and inflammatory responses.
Recent advances in genetic research have provided valuable insights into how Sjögren’s develops. Studies examining gene activity have shown that many of the genes involved are linked to the immune system, particularly pathways related to inflammation and antiviral defense. For example, increased activity of interferons—proteins that help the body respond to viral infections—has been consistently observed in people with Sjögren’s. These findings are helping researchers identify potential biomarkers for diagnosis and new targets for treatment.
Importantly, genetics alone does not determine whether someone will develop Sjögren’s. The disease is thought to arise from a combination of genetic susceptibility and environmental triggers. This helps explain why some individuals with similar genetic profiles may never develop symptoms, while others do.
Looking ahead, ongoing research is focused on uncovering additional genetic factors and understanding how they interact with each other and with environmental influences. Large international studies are bringing together genetic and clinical data from patients around the world, with the goal of improving diagnosis and developing more personalized treatments. As our understanding deepens, there is growing hope that these discoveries will lead to more targeted therapies that address the underlying causes of Sjögren’s.
While there is still much to learn, current research makes it clear that Sjögren’s is not caused by a single factor, but rather by a complex interplay between genes and the environment. Continued advances in this field are paving the way for better care and improved outcomes for those living with the disease.
*summary courtesy of The Sjögren's Book, Fifth Edition, Daniel J. Wallace, MD
