Molecular and clinical aspects of peroxisomal diseases.

Peroxisomal diseases, an expanding group of inborn errors of metabolism, can be classified into three categories--peroxisome biogenesis disorders (PBDs), single peroxisomal enzyme deficiencies, and contiguous gene syndrome. PBDs comprise 13 complementation groups and their responsible genes have been identified, including our newly identified group with a PEX14 defect. We have established a diagnostic system of peroxisomal diseases in Japan, and have identified 40 Japanese with PBDs, 11 patients with beta-oxidation enzyme deficiencies and more than 100 patients with adrenoleukodystrophy. Further study of and enlightenment on peroxisomal diseases is necessary to overcome these disorders.