CLINICAL AND BIOCHEMICAL CHARACTERISTICS OF PEROXISOMAL DISORDERS - AN UPDATE

Peroxisomal disorders represent a recently recognized group of inherit ed diseases in man, now comprising 14 different disorders. If discussi on is restricted to those peroxisomal disorders in which there is neur ological involvement (thereby excluding hyperoxaluria and acatalasaemi a), results over the least few years have shown that analysis of very- long-chain fatty acids (VLCFAs) is a highly reliable initial test to e stablish whether or not one is dealing with a peroxisomal disorder. Rh izomelic chondrodysplasia punctata, its recently identified variant fo rm and glutaryl-CoA oxidase deficiency will show no abnormalities and must be identified by other means. Recently we have found a few clinic ally proven cases of adrenoleukodystrophy showing normal VLCFA in plas ma but clearly abnormal values in fibroblasts. This suggests that grea t care is warranted in interpreting plasma VLCFA analyses. Furthermore , plasma bile acids, phytanic acid, pristanic acid and pipecolic acid should be analysed in any patient with clinical symptoms suggestive fo r a peroxisomal disorder but normal plasma VLCFAs.