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Mucopolysacharidosis are a group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans . These long chains of sugar carbohydrates occur within the cells that help bulid bone , cartilage tendons , corneas , skin , and coonective tissue
Glycosaminoglycans (formerly called mucopolysaccharides ) are also found in the fluids that lubricate joints
Subjects with a mucopolysaccharidosis either do not produce enough of one of the eleven enzymes required to break down these sugar chains into simpler molecules , or they produce enzymes that do not work properly . over time , these Glycosaminoglycans collect in the cells , blood and connective tissue .
the Result is permanent , progressive cellular damage which affects appearance , physical abilities , organs and system functioning and most cases , mental development
The Mucopolysacharidosis are part of the lysosomal storage disease family , a group pf more than 40 genetic disorders that occurs when the lysosomal organelle in cells malfunctions
The mucopolysaccharidoses share many clinical features but have varying degrees of severity. These features may not be apparent at birth but progress as storage of glycosaminoglycans affects bone, skeletal structure, connective tissues, and organs. Neurological complications may include damage to neurons (which send and receive signals throughout the body) as well as pain and impaired motor function. This results from compression of nerves or nerve roots in the spinal cord or in the peripheral nervous system, the part of the nervous system that connects the brain and spinal cord to sensory organs such as the eyes and to other organs, muscles, and tissues throughout the body.
Depending on the mucopolysaccharidosis subtype, affected individuals may have normal intellect or have cognitive impairments, may experience developmental delay, or may have severe behavioral problems. Many individuals have hearing loss, either conductive (in which pressure behind the eardrum causes fluid from the lining of the middle ear to build up and eventually congeal), neurosensory (in which tiny hair cells in the inner ear are damaged), or both. Communicating hydrocephalus—in which the normal reabsorption of cerebrospinal fluid is blocked and causes increased pressure inside the head—is common in some of the mucopolysaccharidoses. Surgically inserting a shunt into the brain can drain fluid. The eye's cornea often becomes cloudy from intracellular storage, and glaucoma and degeneration of the retina also may affect the patient's vision.
Physical symptoms generally include coarse or rough facial features (including a flat nasal bridge, thick lips, and enlarged mouth and tongue), short stature with disproportionately short trunk (dwarfism),dysplasia (abnormal bone size and/or shape) and other skeletal irregularities, thickened skin, enlarged organs such as liver (hepatomegaly) or spleen (splenomegaly), hernias and excessive body hair growth. Short and often claw-like hands, progressive joint stiffness, and carpal tunnel syndrome and can restrict hand mobility and function. Recurring respiratory infections are common, as are obstructive airway disease and obstructive sleep apnea. Many affected individuals also have heart disease, often involving enlarged or diseased heart valves.
Another lysosomal storage disease often confused with the mucopolysaccharidoses is mucolipidosis. In this disorder, excessive amounts of fatty materials known as lipids (another principal component of living cells) are stored, in addition to sugars. Persons with mucolipidosis may share some of the clinical features associated with the mucopolysaccharidoses (certain facial features, bony structure abnormalities, and damage to the brain), and increased amounts of the enzymes needed to break down the lipids are found in the blood. Mps disease is also known as Sanfilippo disease it named after the American doctor Sylvester Sanfilippo, who originally described it in 1963