Genome-wide Association
Study For Rotator Cuff Tears Identifies Two Significant Single-Nucleotide

Tashjian RZ, Granger EK, Farnham JM, Cannon-Albright LA, Teerlink
CC. J Shoulder Elbow Surg. 2015. doi:10.1016/j.jse.2015.07.005.

Take Home Message:
Variations in two genes that are associated with cellular apoptosis may help
identify individuals at risk for rotator cuff injury.  

The underlying cause of rotator cuff tears remains unclear,
which limits our ability to identify individuals at risk for a tear and develop
prevention strategies. A person’s genetics could influence the structure of a
tendon but little research has examined whether variations in a person’s
genetic code could be related to rotator cuff tears. The purpose of this study
was to identify specific genes or genetic variations related to rotator cuff
tears. The authors assessed 311 patients between the ages of 30 and 80 years
with full thickness supraspinatus or infraspinatus tears. To identify specific
genes, the researchers used a “genome-wide association study”. The included
patients provided blood sample so the authors could determine their genetic
variations. For comparison, the researchers selected 2,641 controls from a
database of individuals who previously provided genetic data to other studies. All
of the patients and controls were white. The researchers assessed over 250,000
genetic variations and found two genetic variations that were associated with
rotator cuff tears. These variations were found in two genes that are related
to cell death/apoptosis (SAP30BP on chromosome 17 and SASH1 on chromosome 6).

This study is important because the authors identified genetic
variations on two chromosomes associated with cell death that may indicate that
rotator cuff tears are at least partially heritable. Knowing who is at risk
because of certain genetic variations, would allow of early intervention and
prevention techniques. This knowledge could help clinicians explain to patients
the risk factors for a rotator cuff tear and motivate patients to be cautious
and explore prevention programs. While the results are novel this line of
research should be continued. For example, future studies should recruit
individuals from various ethnic backgrounds so we can determine if these
findings are applicable to individuals other than whites with European
ancestry. A larger sample size may also help researchers identify other genetic
variations that may relate to different types of tears. For example, with
chronic tears, we may find variations in genes related to degeneration (e.g.,
cell death) while a traumatic tear may be related to genes that alter the
tensile strength of a tendon. Despite the need for future research, these
findings may eventually help clinicians identify high-risk patients and prevent
catastrophic or even career-ending injuries. In the meantime, this study
provides information to clinicians that they can use to educate patients about
why some people get rotator cuff tears.

Questions for
Discussions: How do you make the decision to recommend genetic testing? What
are the ethical implications of such testing?

Written by Meredith Bland, Siaura Saville
Reviewed by: Jeffrey Driban

Related Posts:

Tashjian, R., Granger, E., Farnham, J., Cannon-Albright, L., & Teerlink, C. (2015). Genome-wide association study for rotator cuff tears identifies two significant single-nucleotide polymorphisms Journal of Shoulder and Elbow Surgery DOI: 10.1016/j.jse.2015.07.005