Essay On Zellweger Syndrome

Zellweger syndrome is one of a group of four related diseases called peroxisome biogenesis disorders, a group of deadly genetic diseases that claim the lives of children usually before they reach their first birthday. This syndrome is the most common type of peroxisome biogenesis disorder. The disease is caused by defects in any one of 13 genes, called PEX genes, required for the normal formation and function of peroxisomes. Peroxisomes are cell structures that break down toxic substances and synthesize lipids that are necessary for cell function. Peroxisomes are required for normal brain development and function and the formation of myelin, the substance that coats nerve fibers. They are also required for normal eye, liver, kidney, and bone functions. Zellweger spectrum disorders result from dysfunctional lipid metabolism, including the over-accumulation of very long-chain fatty acids and phytanic acid, and defects of bile acids and plasmalogens which are specialized lipids found in cell membranes and myelin sheaths of nerve fibers. (National Institute of Neurological Disorder and Stroke) After being released from cytosolic ribosomes, newly synthesized peroxisomal proteins, unlike mitochondrial chloroplast proteins, generally fold into their mature conformation in the cytosol before being imported into the organelle. Protein import into peroxisomes
The cerebrohepatorenal syndrome of Zellweger is by far the best known genetic disorder of peroxisomal metabolism. Although Zellweger syndrome was first described as a multiple anomaly syndrome in 1964, the discovery in 1973 that hepatic and renal cells of patients with Zellweger syndrome were devoid of recognizable peroxisomes and had dysfunctional mitochondria refocused attention on Zellweger syndrome as a possible metabolic