Metabolic Disease

Several specialized metabolic functions are performed in the subcellular organelles known as peroxisomes. Severe defects in the biogenesis of peroxisomes result in Zellweger syndrome, which is characterized by structural and developmental abnormalities and which is generally fatal in infancy. Defects in individual peroxisomal enzymes are also encountered, including Refsum disease, which results in the buildup of a branched-chain fatty acid (phytanic acid) and progressive problems in the nervous system. A defect in the enzyme alanine-glyoxylate transaminase causes an increase in the production of oxalic acid, an insoluble chemical that is progressively deposited in the tissues of the body and, over years, causes organ dys-function, including renal failure. Renal transplantation does not prevent recurrence, but liver transplantation is effective in preventing the progression of the disease in the kidneys and other organs.