Investigational methods for peroxisomal disorders

Peroxisomes play an important role in cellular metabolism. Defects in peroxisome assembly or of a single peroxisomal pathway are associated with a wide variety of inherited disorders, including X-linked adrenoleukodystrophy, Zellweger spectrum disorders, rhizomelic chondrodysplasia punctata, and Refsum disease. A group of peroxisome-specific biomarkers has been shown to be characteristic of specific defects. Patients with defects in peroxisome fatty acid beta-oxidation accumulate very long-chain fatty acids (VLCFA), patients with defects in plasmalogen synthesis are deficient in erythrocyte membrane plasmalogens, and patients with mislocalized pipecolic acid oxidase accumulate pipecolic acid in body fluids. This unit describes three protocols that can be used to measure plasma VLCFA, erythrocyte plasmalogens, and plasma or urine pipecolic acid by capillary gas chromatography (GC) or GC-mass spectrometry. These techniques can be used to identify the majority of patients with known neurogenetic peroxisome disorders.