PEROXISOMAL DISORDERS - A REVIEW

Until recently peroxisomal disorders were considered to be extremely r are and the diagnostic procedures available for postanatal and prenata l diagnosis were not widely known. At present, 17 human disorders are linked to peroxisomal dysfunction. The clinical, biochemical and morph ological peroxisome heterogeneity described in the different diseases illustrate that only combined analysis of all the different approaches will lead to a correct diagnosis and a coherent pathophysiological mo del to guide ongoing research. With the study of human peroxisomal dis easese, advances have been gained as to the function of the peroxisome in normal and pathological conditions. Genetic analysis of peroxisome biogenesis and research on peroxisomal targeting signals are now in p rogress. Peroxisomal disorders are usually classified according to the degree of biochemical impairment. In this paper, a tentative classifi cation of peroxisomal disorders will be proposed, based on the degree of biochemical abnormalities combined with new data obtained on whethe r or not defective peroxisome assembly is involved: (1) disorders with peroxisome assembly deficiencies; (2) disorders with single enzyme de ficiencies. The clinical onset and the major symptoms of the various d isorders, and the recently discovered findings are discussed.