Peroxisomes are organelles present in all eukaryotic cells from yeast to human cells. It is now well known that approximately fifty different biochemical reactions occur within the peroxisome, including synthesis of bile acids, cholesterol, ether-phospholipids (plasmalogens), docosahexaenoic acid and catabolism of certain fatty acids, particularly very long chain fatty acids (VLCFAs). Proteins involved in peroxisomal function are known as peroxins. At least 29 peroxins are required for peroxisome membrane biogenesis, fission, and protein import. So far, mutations in 13 genes that encode peroxins are associated with human disease. Peroxisomal disorders currently falling into one of three groups peroxisome biogenesis disorders (PBDs), peroxisomal multi-enzyme disorders, and peroxisomal single-enzyme disorders. Infantile Refsum’s disease (IRD), neonatal adrenoleukodystrophy (NALD) and Zellweger’s syndrome (ZS) are different variants of a group of congenital diseases known as peroxisome biogenesis disorders. These disorders are characterized by the absence of normal peroxisomes in the cells of the body which mostly are fatal. Here we describe molecular events that cause these deficiencies and we introduce current molecular approaches for diagnosis of these disorders like mutation analysis and fibroblasts characterization derived from the patients
