Peroxisomes are organelles surrounded by membrane in the form of spheres. Peroxisomes play an important role in beta oxidation of very long chain fatty acids (C22:0, C24:0, C26:0) and alpha oxidation of 3-methyl fatty acids (phytanic acid). The Zellweger syndrome is best known peroxisomal disorders. Zellweger syndrome is a rare disease characterized by decreased or absent peroxisomes in the cells of the liver, kidney and brain. Increased levels of very long chain fatty acids (VLCFA) in blood and decreased plasmalogen levels in erythrocytes are the most important parameters to aid in diagnosis.
VERY LONG CHAIN FATTY ACIDS, PRISTANIC AND PHYTANIC ACIDS
The diagnosis of X-ALD may be raised by the above clinical signs or symptoms, including isolated adrenal insufficiency and is commonly achieved by laboratory evaluation of increased concentrations of VLCFA in plasma. Testing typically includes three VLCFA parameters: the level of hexacosanoic acid (C26:0), and the ratio of hexacosanoic acid to tetracosanoic acid (C26:0/ C24:0), and to docosanoic acid (C26:0/C22:0).