Iduronidase
Encyclopedia
Iduronidase is an enzyme involved in the degeneration of glycosaminoglycan
s such as dermatan sulfate
and heparan sulfate
. It is found in the lysosome
s of cells.
and type I,S is known as Scheie syndrome
, which has a milder prognosis compared to Hurlers. The glycosaminoglycans accumulate in the lysosome
s and cause substantial disease in many different tissues of the body.
The defective alpha-L-iduronidase results in an accumulation of heparan and dermatan sulfate within phagocytes, endothelium, smooth muscle cells, neurons, and fibroblasts. Underneath electron microscopy these structure present as laminated structures, Zebra bodies.
Prenatal diagnosis of this enzyme deficiency is possible.
Glycosaminoglycan
Glycosaminoglycans or mucopolysaccharides are long unbranched polysaccharides consisting of a repeating disaccharide unit. The repeating unit consists of a hexose or a hexuronic acid, linked to a hexosamine .-Production:Protein cores made in the rough endoplasmic reticulum are posttranslationally...
s such as dermatan sulfate
Dermatan sulfate
Dermatan sulfate is a glycosaminoglycan found mostly in skin, but also in blood vessels, heart valves, tendons, and lungs....
and heparan sulfate
Heparan sulfate
Heparan sulfate is a linear polysaccharide found in all animal tissues. It occurs as a proteoglycan in which two or three HS chains are attached in close proximity to cell surface or extracellular matrix proteins...
. It is found in the lysosome
Lysosome
thumb|350px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: [[nucleoli]] [[cell nucleus|nucleus]] [[ribosomes]] [[vesicle |vesicle]] rough [[endoplasmic reticulum]]...
s of cells.
Pathology
Its deficiency is associated with mucopolysaccharidoses (MPS). MPS, a lysosomal storage disease, is typed I through VII. Type I is known as Hurler syndromeHurler syndrome
Hurler syndrome, also known as mucopolysaccharidosis type I , Hurler's disease, also gargoylism, is a genetic disorder that results in the buildup of glycosaminoglycans due to a deficiency of alpha-L iduronidase, an enzyme responsible for the degradation of mucopolysaccharides in lysosomes...
and type I,S is known as Scheie syndrome
Scheie syndrome
Scheie syndrome ") is less severe version of Hurler's disease. It is a condition characterized by corneal clouding, facial dysmorphism, and normal lifespan but unlike Hurler's, disease has normal intellect and ....
, which has a milder prognosis compared to Hurlers. The glycosaminoglycans accumulate in the lysosome
Lysosome
thumb|350px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: [[nucleoli]] [[cell nucleus|nucleus]] [[ribosomes]] [[vesicle |vesicle]] rough [[endoplasmic reticulum]]...
s and cause substantial disease in many different tissues of the body.
The defective alpha-L-iduronidase results in an accumulation of heparan and dermatan sulfate within phagocytes, endothelium, smooth muscle cells, neurons, and fibroblasts. Underneath electron microscopy these structure present as laminated structures, Zebra bodies.
Prenatal diagnosis of this enzyme deficiency is possible.