Test Background Phytanic acid is a 3-methyl fatty acid and so can only be oxidised in the peroxisome. Refsum’s disease, an inherited metabolic disease characterised by retinitis pigmentosa and polyneuropathy, results from deficient activity of the enzymes involved in this process.
Clinical Indications Monitoring of diagnosed Refsum’s disease.
Reference Range See report
Sample Required SST (gold top), serum (red top) or heparin (green top)
Sample Volume 0.5 mL
Turnaround Time Up to 3 weeks
Notes Not currently performed in house; this is a referred test. Sometimes pristanic acid is also required. This is included within the very long chain fatty acid (VLCFA) profile.