[Refsum disease--rare, but world-famous].

Sigvald Bernhard Refsum (1907-91) was an outstanding Norwegian neurologist, highly respected and recognised both nationally and internationally. His main scientific achievement was that he by clinical means singled out a previously unknown disease entity in the multitude of different neurodegenerative features. In his monograph from 1946 he named the disease "heredopathia atactica polyneuritiformis"; however, it was rapidly known as Refsum's disease. Twenty years later, two German scientists, Klenk and Kahlke, detected large amounts of a peculiar branched-chain fatty acid, phytanic acid, in a Refsum patient. This started an amazing revelation of the biochemical background of the disease, and also led to a logical and effective treatment. Although Refsum's disease is extremely rare, it has become well-known due to this elucidation of both the normal metabolism of phytanic acid and the pathophysiology of the disease.