There are many different forms of illnesses called leukodystrophies. These typically have a genetic basis and cause the body to have trouble maintaining appropriate myelin sheaths, or the white material composed of proteins and fats that help to protect nerve cells. One of these conditions is Refsum disease, which is present at birth, but usually doesn’t begin to manifest symptoms until people are young adults, or more rarely, when people are in mid-life. The condition can have serious effects, but also is usually treatable.
The cause of Refsum disease has been identified to a point. People lack the appropriate genetic material to produce an enzyme that will digest phytanic acid. Humans don’t produce this acid but they do get it in food on a frequent basis. Over time, this acid builds up, and begins to damage myelin sheaths causing a variety of progressive symptoms. It’s also known that Refsum is caused by genetic inheritance in an autosomal recessive pattern. This means people must inherit a defective gene from each parent for the illness to occur.
The varied expressions of Refsum disease include degeneration of hearing and eyesight. In particular retinitis pigmentosa may occur, where the retina begins to deteriorate. This may first show up as night blindness and may progress to total blindness. The eyes can be affected in other ways and some people have involuntary eye movement or abnormal pupils.
Muscle weakness, pain, reduced reflexes or burning sensations might result due to a condition called peripheral polyneuropathy. People may also have difficulty maintaining balance. Another condition associated with Refsum disease is icthyosis: a scaly rash. Lastly some people have noted shortening of the limbs and especially may have a short fourth toe.
Symptoms of Refsum disease are called progressive because they will worsen if the condition isn’t treated. However, speed at which the illness progresses isn’t always predictable. In worse case scenarios, the disease becomes fatal, and prior to discovering how to treat Refsum, it had a high early mortality rate, as much as 50%. Yet, since the medical field now understands the mechanisms by which this condition works, these numbers have been greatly reduced.
The primary means for treating this condition are to restrict diet to avoid those foods that contain high amounts of phytanic acid. Foods that usually fall into this category include things like red meat and dairy products. Since this acid accumulates, it may be necessary to occasionally do things like blood plasmapheresis, which removes blood from the body, filters it, and then returns it. This may help reduce phytanic acid levels and might be particularly important if people lose weight, because the breakdown of fat cells releases phytanic acid into the bloodstream.
As long as people can remain on a diet free of the foods that are most likely to cause more phytanic acid build-up, they may remain free of symptoms. Some symptoms of the disease may improve, but certain conditions like blindness and deafness, if they are already present, might not get better with treatment. People will require careful following if they have this condition, and it cannot be stressed enough that remaining on the proposed diet is the best hope of maintaining health.
