HLA-B27 is a gene associated with the occurrence of which condition?

HLA-B27 is a gene associated with the occurrence of which condition?

• A. Ankylosing spondylitis
• B. Osteoporosis
• C. Gout
• D. Fibromyalgia

Answer: (A)

HLA-B27 is a genetic marker strongly linked to inflammatory joint diseases, especially ankylosing spondylitis. It encodes a class I MHC molecule, and its presence increases the likelihood of developing seronegative spondyloarthropathies. In someone with inflammatory back pain and sacroiliitis, a positive HLA-B27 test supports the possibility of ankylosing spondylitis, though it isn’t diagnostic on its own because many healthy people carry the marker and some patients with AS are HLA-B27 negative. The other conditions listed—osteoporosis, gout, and fibromyalgia—do not have a meaningful association with HLA-B27, so they’re not typically linked to this genetic finding.

HLA-B27 is a genetic marker strongly linked to inflammatory joint diseases, especially ankylosing spondylitis. It encodes a class I MHC molecule, and its presence increases the likelihood of developing seronegative spondyloarthropathies. In someone with inflammatory back pain and sacroiliitis, a positive HLA-B27 test supports the possibility of ankylosing spondylitis, though it isn’t diagnostic on its own because many healthy people carry the marker and some patients with AS are HLA-B27 negative. The other conditions listed—osteoporosis, gout, and fibromyalgia—do not have a meaningful association with HLA-B27, so they’re not typically linked to this genetic finding.