Mar 5, 2021

Disease Spotlight: Adult Refsum Disease

With a prevalence of one in 1 million, adult Refsum disease (ARD) is an inherited metabolic disorder that is one of the rarest causes of retinitis pigmentosa. People with ARD have a genetic mutation that prevents them from breaking down a fat called phytanic acid found in many foods, including some dairy, red meat, and fish. Overtime, in individuals with this genetic mutation, phytanic acid builds up in the body leading to symptoms such as vision loss.

ARD usually begins in childhood or early adulthood, although some individuals may not develop symptoms until their 40’s or 50’s. The disease can be difficult to diagnose because of its varied symptoms and rare incidence. Diagnosis is based on blood levels of phytanic acid and confirmation through genetic testing. The main treatment for ARD is to avoid food that contains phytanic acid.

Common symptoms of ARD include:

• Night blindness and peripheral vision loss caused by retinitis pigmentosa (often one of the first symptoms)
• Hearing loss
• Dry or scaly skin
• Peripheral neuropathy (numbness in the hands and feet)
• Loss of sense of smell
• Joint pain
• Cardiac arrhythmias (heartbeat abnormalities)

Treatment for ARD includes avoiding foods high in phytanic acid. ARD research has identified several foods that are high in phytanic acid, including:

• Full fat dairy products
• Some red meat (specifically beef)
• Most fatty fish
• Products that include ingredients from the above products

Other treatments involve preventing fat burning activities like exercise, weight loss, stress, and illness. Avoiding these activities lowers the amount of phytanic acid released into the blood. A treatment called plasmapheresis may be used if levels of phytanic acid in the blood are too high and cause severe symptoms (requiring hospitalization). Plasmapheresis directly removes phytanic acid from the blood in a process like dialysis.

Such forms of treatment often reduce or even stop many of the symptoms, including numbness and ichthyosis. Vision and hearing loss may not improve, although it is suspected that treatment can slow further progression.

If you have questions about adult Refsum disease, or any other eye health related questions, please contact our health information line at 1.888.626.2995 or healthinfo@fightingblindness.ca.

If you are experience any changes in your vision, please contact your eye doctor as soon as possible.

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