Ankylosing spondylitis (AS) is a mysterious autoimmune system that often affects the joints of the spine.

Despite the fact that AS can appear in a 17-year-old boy or a 40-year-old woman, one common factor exists for nearly everyone with the condition: a genetic marker known as HLA-B27.

Genetic marker HLA-B27 is common amongst all AS patients. Watch: Ankylosing Spondylitis Video

Since AS seems to be partially caused by genetics, does this mean their family members who share similar genes are also at risk? One set of researchers set out to answer this question.

See Ankylosing Spondylitis Causes and Risk Factors

For the study, researchers found 51 seemingly healthy first degree relatives (parent, child, or sibling) of someone with diagnosed AS and the HLA-B27 marker. They were then tested for signs of AS in clinical, biological, and imaging tests.1


The results revealed that out of the 51 relatives tested:

  • 29 experienced back pain
  • 17 met a set of criteria for having AS
  • 10 had irregularities in the sacroiliac joints, a common site of initial AS symptoms

The study seems to indicate that a significant proportion of first degree relatives of someone with AS have clinical or imaging abnormalities that suggest AS. However, this is a relatively small study, and more research is needed.

Ankylosing spondylitis can’t be cured or prevented, but knowing your risk is important. The sooner it’s diagnosed and treated, the better it can be managed and its progress slowed.

See Ankylosing Spondylitis Treatment

Learn more:

What Is Ankylosing Spondylitis?

Ankylosing Spondylitis Symptoms


  • 1.Clinical and imaging signs of spondyloarthritis in first-degree relatives of HLA-B27 positive ankylosing spondylitis patients: The pre-spondyloarthritis (Pre-SpA) cohort. Turina MC et al. Arthritis Rheumatol. 2016 May 23. doi: 10.1002/art.39766. [Epub ahead of print].