Neurological disorders and phytanic acid metabolism

Area of Science:

• Neurology
• Metabolic Disorders
• Biochemistry

Background:

• Refsum's disease is a rare genetic disorder characterized by the accumulation of phytanic acid.
• Atypical or mild forms of Refsum's disease have been hypothesized but not clearly defined.
• Neurological symptoms like retinitis pigmentosa and ataxia can present diagnostic challenges.

Purpose of the Study:

• To investigate the role of phytanic acid in patients presenting with neurological symptoms suggestive of Refsum's disease.
• To determine serum phytanic acid levels and fibroblast phytanic acid oxidase capacity in these patients.
• To evaluate the existence of atypical or mild Refsum's disease phenotypes.

Main Methods:

• Serum phytanic acid levels were quantified in 50 patients with neurological signs.
• Phytanic acid oxidase activity was assessed using alpha-oxidation of (1-14C) phytanic acid in skin fibroblasts.
• Clinical data including retinitis pigmentosa, cerebellar ataxia, and polyneuropathy were analyzed.

Main Results:

• All 50 patients exhibited normal serum phytanic acid levels.
• Phytanic acid alpha-oxidation capacity in skin fibroblasts was found to be normal across all subjects.
• No evidence supported the presence of increased phytanic acid or impaired metabolism.

Conclusions:

• The study found no support for the existence of atypical or mild Refsum's disease.
• Refsum's disease appears to be a distinct genetic disorder with a specific phenotype.
• Neurological symptoms in the studied cohort were not attributable to phytanic acid accumulation.