The significance of plasma phytanic acid levels in adults.

The presence of phytanic acid in tissues and plasma has been considered diagnostic of heredopathia atactica polyneuritiformis (Refsum's disease), but recently slightly raised plasma phytanic acid levels have been reported in other conditions. Forty two normal people were found to have a phytanic acid level of 0-33 mumol/l. Fourteen patients with heredopathia atactica polyneuritiformis had a plasma phytanic acid level before treatment of 992-6400 mumol/l.

Heredopathia atactica polyneuritiformis: Refsum's disease.

Seven patients with Heredopathia Atactica Polyneuritiformis are described. There were 3 groups of clinical characteristics: first, congenital abnormalities such as skeletal deformities, unrelated to phytanic acid levels; second, signs and symptoms such as retinitis pigmentosa which come on slowly and are not directly related to the plasma phytanic acid level; third, lesions such as the neuropathy, rash and cardiac arrhythmias which can change quickly and are linked to the plasma phytanic acid level. Exacerbations of the signs in the third group are precipitated by a low calorie intake and mobilisation of phytanic acid from the adipose tissue.