The inborn errors of peroxisomal β‐oxidation: A review

Summary In recent years a growing number of inherited diseases in man have been recognized in which there is an impairment in peroxisomal β‐oxidation. In some diseases this is due to the (virtual) absence of peroxisomes leading to a generalized loss of peroxisomal functions including peroxisomal β‐oxidation. In most inborn errors of peroxisomal β‐oxidation, however, peroxisomes are normally present and the impairment in peroxisomal β‐oxidation is due to the single or multiple loss of peroxisomal β‐oxidation enzyme activities. In all these disorders there is accumulation of very‐long‐chain fatty acids in plasma, which allows biochemical diagnosis of patients affected by an inborn error of peroxisomal β‐oxidation to be done via gas‐chromatographic analysis of plasma very‐long‐chain fatty acids. Subsequent enzymic and immunological investigations are required to identify the precise enzymic defects in these patients. In all inborn errors of peroxisomal β‐oxidation known today there are multiple abnormalities, especially neurological with death usually occurring in the first decade of life. Prenatal diagnosis of these disorders has recently become possible.