Rotator cuff pain? Genetics might be to blame

Rotator cuff disease is a common disorder that affects 30 to 50 percent of people over the age of 50. The disease often leads to shoulder pain and loss of function. While many think of this as a 'tear' due to an injury or sustained over/misuse, some studies suggest genetics might play a role.

"People are living longer and more active lives, but a large percentage of these people may suffer from rotator cuff disease," explains Lead Investigator in the study, Dominique Dabija, MS, a medical student at Vanderbilt University School of Medicine. "Identifying a genetic link can help early recognition of individuals at higher risk and could warrant application of prevention strategies for this specific population.

To assess if there could be a genetic or familial predisposition to rotator cuff disease, Dabija -- along with Chan Gao, MD, PhD; Todd L. Edwards, MS, PhD; John Kuhn, MD, MS; and Nitin B. Jain, MD, MSPH, also from Vanderbilt University Medical Center -- looked through two databases (PubMed and EMBASE) that hold thousands of medical research studies to identify those using the term "rotator cuff." They searched all studies in the databases through March 2016 and narrowed down 251 citations to seven studies that were relevant to their literature review.

"Different studies on similar topics may produce different results depending on the specific methods and populations looked at," explains Dabija. "Our literature review compiles all of these studies to look at the data on a larger scale, and this allows us to identify macro trends as well as research gaps that need to be filled."

Four of the seven studies reviewed by Dabija's team assess whether there is a familial predisposition to rotator cuff disease. One of these found if an individual has a sibling with a rotator cuff tear, he or she is twice as likely to also have a tear and nearly five times more likely to have associated pain and loss of function. This is in comparison to if that individual did not have a sibling with a tear.

Another study reviewed by Dabija's team showed that a significantly higher number of individuals with tears (32.3 percent) had family members with a history of tears or surgery on their rotator cuffs than those without tears (18.3 percent).

A third study found if an individual is diagnosed with a rotator cuff tear before the age of 40, there is a higher likelihood that any of his or her family members -- immediate or extended -- will also have a tear. In contrast, if an individual is diagnosed with a rotator cuff tear after the age of 40, only close family members -- parents, siblings, grandparents, aunts/uncles -- have a higher likelihood of having a tear. This difference may also be attributed to environmental factors.

The other three studies investigated whether there is a genetic predisposition to rotator cuff disease, and these noted certain patterns of genes were found more often in people with rotator cuff disease when compared to those without rotator cuff disease.

"Although there was a small number of studies in this literature review -- pointing to a need for more studies on this topic -- the consensus among all seven studies is rotator cuff disease is a heritable trait," says Dabija. "More large-scale studies need to be performed, and these results can assist in identifying individuals at higher risk of developing a tear and then help them before they have pain."