The peroxisome is another of the membrane-bound subcellular organelles. It had been known morphologically as microbodies before de Duve characterized it biochemically. Its physiological functions are more complex and diverse than those of the lysosome. Known functions of the peroxisome include metabolism of very long-chain fatty acids, pipecolic acid, dicarboxylic acids and phytanic acid and biosynthesis of plasmalogens and bile acids. By analogy to the lysosomal diseases, there is now recognized a group of inherited disorders caused by genetic defects in the peroxisomes themselves or the enzymes normally localized in the peroxisome. Many of these diseases manifest primarily as neurological disorders [3].