Mucopolysaccharidoses



- Discussion:
    - are characterized by a defect in metabolism of one or more mucopolysaccharides, w/ resulting excessive accumulation of these 
           substances in the extracellular spaces of the connective tissues;
    - this group of disorders is characterized by a deficiency of specific lysosomal enzymes required for degradation of glycosaminoglycans;
           - substances accumulate in tissues such as brain, viscera, heart, lung, and joints;
    - clinical features:
           - coarse facial features
           - short stature
           - platyspondyly with an anterior tongue
           - broad medial end of the clavicle
           - characteristic pelvis with flared iliac wings
           - large capacious acetabula
           - unossified femoral head cartilage with coxa valga;

- Specific Disorders:
    - Morquio's syndrome;
    - Hurler-Scheie:
           - most severe mucopolysaccharide storage disorder which causes cardiopulmonary complications and results in death within first 
                  decade of life;
           - patients are usually diagnosed between the ages of 1-3 years;
           - enzyme defect may be detected in the blood and on skin bx, which allows accurate dx, carrier detection, and prenatal dx;
           - course facial features (thickened lips, widened nostrils, large ears) and hepatosplenomegaly are seen be 18 months of age;
           - other characteristics include:
                  - short stature, w/ disproportionately short trunk, thoracolumbar kyphosis (anterior-inferior vertebral beaking);
                  - elbow, hip, and knee flexion contractures;
                  - atlantoaxial instability has now been demonstrated & screening for instability is now suggested;
                  - corneal opacities;
           - labs: increased urine heparin and dermatin sulfate;
    - Hunter:
           - sex linked recessive disorder which is also characterized by increased heparin and dermatin sulfate;
           - usually clear cornea
           - mild course: later manifestation and survival into adulthood w/ or without mental retardation;
    - San Filippo's syndrome:
           - presents in early childhood and progresses in severity;
           - may be confused with cerebral palsy because patients have hyper-reflexia and spasticity, however, unlike cerebral palsy, this 
                   disorder progresses in severity;
           - patients have the course facial features seen in other mucopolysaccharidoses;
           - urine is positive for heparin sulfate



Hurler syndrome with special reference to histologic abnormalities of the growth plate.

Musculoskeletal manifestations of hurler syndrome: long-term follow-up after bone marrow transplantation.

Cord-Blood Transplants from Unrelated Donors in Patients with Hurler's Syndrome.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, May 21, 2012 4:01 pm