Morquio Disease (MPS IV)
Morquio Disease (MPS IV)
Morquio disease also known as MPS IV, a mucopolysaccharide diseases named after Dr. Luis Morquio, a physician in Parguay who in 1929 described a family of four children affected by the condition.
MPS IV is an autosomal recessive disorder caused by a deficiency in the enzyme responsible fro the metabolism of keratin sulphate. There are two subtypes, type A and B. MPSIVA is caused by the enzyme deficiency N-Acetylgalactosamine-6-sulfatase encoded at chromosome 16q24.3. MPSIVB is caused by the enzyme deficiency Beta-galactosidase encoded at chromosome 3p21.3. The incompletely broken down mucopolysaccharides cannot be used in the proper development of bones and cartilage and remain stored in cells in the body causing progressive damage. Babies may show little sign of the disease but, as storage progresses, the disease becomes more clinically obvious. Subtype B may be more mild in presentation.
Some clinical features of MPSIV include abnormal skeletal development, hypermobile joints, large fingers, widely spaced teeth, coarse features, macrocephaly (large head), bell-shaped chest, compression of the spinal cord, short stature, and abnormal heart development.
Currently, there is treatment for symptoms, but no cure for the underlying disease. Bone marrow transplant was tried but with disappointing results and is not recommended as a treatment for Morquio disease.
