Phytanic Acid Storage Disease, also known as Refsum disease, is a rare metabolic disorder that affects the breakdown and metabolism of phytanic acid in the body. Other synonyms for this condition include heredopathia atactica polyneuritiformis, adult Refsum disease, and phytanic acid oxidase deficiency. These terms all refer to the same disorder, which can cause a range of symptoms including muscle weakness, vision loss, hearing problems, and numbness or tingling in the hands and feet. Although there is no cure for Phytanic Acid Storage Disease, treatment can help manage symptoms and improve quality of life for those affected.