Refsum's disease is characterized by increased levels of

Ans. a (Phytanic acid). (Ref. Harper, Biochemistry, 25th ed., 248)REFSUM'S DISEASE is a rare neurologic disorder due to a defect (absent phytanic acid oxidase enzyme) that causes the accumulation of phytanic acid, which is found in plant foodstuffs and blocks beta-oxidation.DISORDERS DUE TO PEROXISOMAL ABNORMALITIES# Zellweger syndrome- Neonatal adrenoleukodystrophy- Infantile Refsum disease# Hyperpipecolic acidemia- Acatalasemia- Adrenoleukodystrophy# Pseudo-adrenoleukodystrophy- Hyperoxaluria type- Pseudo-Zellweger syndrome# Rhizomelic chondrodysplasia punctata- Glutaryl-CoAoxidase deficiency (Note: Zellweger syndrome is the most severe and infantile Refsum disease is the least severe form)