[Refsum's disease. Epidemiologic, clinical and biological correlation. 6 cases].

Nine patients with symptoms and signs of Refsum's disease are reported. In 6 a systemic accumulation of phytanic acid was demonstrated, together with low phytanic acid oxidase activity in skin fibroblasts in 5 of them. In 3, no disorder of phytanic acid metabolism was demonstrated. In 3, the diagnosis was made during the pre-clinical period. The disease seems more frequent in Northern France, which agrees with the hypothesis of a genetic mutation which would have taken place in Scandinavia some centuries ago and was subsequently spread by the Vikings. The effects of a dietary treatment on serum phytanic acid levels and clinical disorders are reported. The general condition of the patients improved remarkably but only partially. The diet is unpalatable and in some patients the level of serum phytanic acid increased, due to the mobilization of body fat. Patients with very high levels of phytanic acid might be initially treated by plasmapheresis. For the same reason, the diet should supply enough calories to keep body weight unchanged, and body weight loss whatever its cause should be avoided.