Hunter Syndrome Research Paper

Lysosomal storage diseases are rare, inherited disorders caused by the deficiency of one or more enzymes within the lysosomes of cells. Hunter Syndrome also known as mucopolysaccharidosis disorder II (MPS II), is a genetic abnormality occurring in canines and humans. It is a rare X-linked recessive metabolic storage disorder caused by the deficiency of the lysosomal enzyme iduronate-2-sulphatase, which is needed to breakdown complex sugars produced in the body, leading to progressive accumulation of glycosaminoglycans in almost all cell types, tissues, and organs. Which can affect every system in the dog’s body. The mucopolysaccharides, which aid in bone formation, as well as the skin, cornea, and cartilage, do not perform their function
Some puppies are born with an abnormally big forehead, and a broad mandible. Dogs usually have bowed rear legs and have difficulty walking. Some other signs are heart murmurs , chronic diarrhea, respiratory issues, skeletal deformities, liver and spleen enlargement, enlarged tongue, vision problems, degenerative joint disease, and developmental delays. MPS share many clinical features which include a chronic and progressive course, multisystem involvement, organomegaly, facial and skeletal dysmorphisms, degenerative joint disease, corneal clouding, and thickening and distortion of the heart valves. Some ways to help examine the dog and help possibly diagnose is with a radiographic examination. It can help show bony malformations in the animal that appear dysmorphic. Bony and connective tissue abnormalities usually characterize MPS, although they can be seen in other storage diseases. Magnetic Resonance Imaging or MRI have detected some lysosomal storage diseases. There are few veterinary patients that have been investigated this way, so there is little information in this area. But some veterinarians are using it and will put out data about it. Another way to diagnose is by an analysis of urine for abnormal excretion of storage products. Thin-layer chromatography is often used to separate abnormal oligosaccharides and glycopeptides in the urine. There is also the MPS spot test, that stains urine on
In humans, MPS II can be expressed in a mild, intermediate, or severe form based on clinical signs with equivocally levels of enzyme in each form. The severe form occurs in children and results in skeletal deformities and neurodegeneration. The mild form occurs in adults and has a slower less debilitating course with preservation of intelligence. The clinical progression and biochemical characteristics of the enzyme defect in this dog best correlate with the intermediate form of the human disease.”
Even though lysosomal storage diseases are rare disorders, many veterinarians are unable to reach a specific diagnosis because they do not understand the disease group very well and because they do not have the testing techniques to make a diagnosis. There will be advances in the molecular genetic basis of storage diseases, that will help both humans and