Refsum Disease (Phytanic Acid Storage Disease, Heredopathia Atactica Polyneuritiformis)
What is Refsum Disease?
Adult Refsum disease (ARD) is one of a group of genetic diseases called leukodystrophies, which damage the white matter of the brain and affect motor movements. Due to a genetic abnormality, people with ARD disease lack the enzyme that breaks down phytanic acid, a substance commonly found in foods. As a result, toxic levels of phytanic acid build up in the brain, blood, and other tissues. The disease usually begins in late childhood with increasing night blindness due to degeneration of the retina (retinitis pigmentosa) and loss of the sense of smell (anosmia). If the disease progresses, other symptoms may include deafness, problems with balance and coordination (ataxia), weakness or numbness (peripheral neuropathy), dry and scaly skin (ichthyosis), and heartbeat abnormalities (cardiac arrhythmias). Some individuals will have shortened bones in their fingers or toes, or a visibly shortened fourth toe. Although the disease usually appears in early childhood, some people will not develop symptoms until their 40s or 50s.