Ankylosing Spondylitis Cause, Genetics, and Other Important Information

Ankylosing Spondylitis Cause, Genetics, and Other Important Information
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Ankylosing spondylitis is a chronic disease characterized by the joints between the spinal bones being inflamed. The joints located between the pelvis and spine are also often inflamed. Eventually, this condition will cause the spinal bones that are affected to join together. The onset of this disease is typically between 20 and 40 years of age, though, it can start before 10 years of age.

How Common is this Genetic Disorder?

This disorder is part of a group of associated disorders referred to as spondyloarthropathies. In the United States, this group of disorders affects 3.5 to 13 per 1,000 people.

Genetics of Ankylosing Spondylitis

It is thought that a combination of both environmental and genetic factors are responsible for causing ankylosing spondylitis. However, most of these have yet to be identified as an ankylosing spondylitis cause, but researchers have discovered variations in several genes can increase a person’s risk of developing this disorder. The genes associated with this disorder include ERAP1, IL1A, HLA-B, and IL23R.

This disorder is not purely genetic, however, as environmental and other factors can act as triggers. It is more accurate to say that susceptibility to the disease, rather than the disease itself, is an inheritable trait.

Symptoms of Ankylosing Spondylitis

Ankylosing spondylitis begins with intermittent lower back pain. Some characteristics of this back pain include:

  • Stiffness and pain that is more severe at night, during periods of inactivity, and in the morning. The pain can wake the patient up from sleep.
  • The pain tends to improve with exercise or activity.
  • The pain may begin between the spine and pelvic (sacroiliac joints) and then involve part or all of the patient’s spine over time.
  • Loss of mobility or motion in the lower spine can occur. It may also be difficult to fully expand the chest if the joints located between the ribs are affected.
  • Fatigue is a common symptom as well.

Less common symptoms can include:

  • Uveitis or eye inflammation
  • Hip stiffness and pain
  • Loss of appetite
  • Weight loss
  • Heel pain
  • Slight fever
  • Joint pain and swelling affecting the knees, shoulders, and ankles

In rare cases, complications such as heart rhythm problems, and aortic insufficiency can occur. Restrictive lung disease or pulmonary fibrosis are also possible.

Diagnosing this Genetic Disorder

In addition to a physical exam, the doctor may perform additional tests, including:

  • CBC blood test
  • HLA-B27 antigen blood test
  • ESR blood test
  • X-rays of the pelvis and spine

How is Ankylosing Spondylitis Treated?

Non-steroidal anti-inflammatory drugs are often prescribed to treat inflammation and pain. Corticosteroid and immunosuppressant therapy may be beneficial for some patients. Cytotoxic drugs may help those who do not get adequate relief with corticosteroids. In cases where the joint damage or pain is severe, surgery may be performed.

Resources

Genetics Home Reference. (2010). Ankylosing Spondylitis. Retrieved on June 24, 2010 from Genetics Home Reference: https://ghr.nlm.nih.gov/condition/ankylosing-spondylitis

Medline Plus. (2009). Ankylosing Spondylitis. Retrieved on June 24, 2010 from Medline Plus: https://www.nlm.nih.gov/medlineplus/ency/article/000420.htm

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