Adhesive Capsulitis Linked to Specific Gene Locations

Individuals with adhesive capsulitis carry gene variants that put them at risk for developing the disease, according to a recent study.

Adhesive capsulitis, or frozen shoulder, is one of the most common shoulder conditions, occurring in up to 10% of individuals at some point in their lives. Patients with frozen shoulder have decreased shoulder mobility with associated pain. The loss of motion results from scarring of the capsule around the shoulder joint. Although the cause is unclear, frozen shoulder can occur after an injury or surgery.

In the current study, researchers investigated specific genes associated with an increased risk of the condition. Using data from the UK Biobank, the researchers conducted a genome-wide association study that compared individuals diagnosed with adhesive capsulitis (n = 2,142) to people without the condition. Additionally, the researchers conducted 2 separate studies using the same data and method but controlled the data for 2 known risk factors: hypothyroidism and diabetes.

The results of the study showed 3 loci with a significant association with adhesive capsulitis. The strongest association was found at a site called WNT7B, while weaker associations were also found at MAU2 and POU1F1.

The findings potentially add to our knowledge regarding the development of adhesive capsulitis. The current study confirmed previous reports, which also found associations between WNT7B and frozen shoulder. This is an important confirmation because WNT7B is involved in regulating fibrosis (or scarring). The 2 newly reported loci, POU1F1 and MAU2, are involved with cell division, which could help researchers determine the cellular mechanism by which frozen shoulder develops.

Further, when looking at the controlling for hypothyroidism (OR = 1.70, 95% CI, 1.18 to 2.36) and diabetes (OR = 4.23 (95% CI, 2.32 to 7.05), the researchers found a consistent significance.

By identifying several gene loci, researchers may have the ability to predict a clinically relevant risk of frozen shoulder.

“Refining the genetic risk metric and including it in a larger clinical model could allow patients at risk for future adhesive capsulitis to be identified, leading to efforts at prevention, early diagnosis, and ultimately improved outcomes,” the researchers concluded.

—Jessica Ganga

Reference:

Kulm S, Langhans MT, Shen TS, Kolin DA, Elemento O, Rodeo SA. Genome-wide association study of adhesive capsulitis suggests significant risk factors. J Bone Joint Surg Am. Published online October 12, 2022. doi: 10.2106/JBJS.21.01407