Mucopolysaccharidoses (MPS) I, II, and VI are a group of rare, lysosomal storage diseases in which certain enzymes are missing that are normally required for breaking down specific complex carbohydrates. Deficiencies in these enzymes result in the build-up of toxic substances in various tissues and cause damage to the body's organs. In the past, children diagnosed with MPS I, II, or VI frequently died in early to late childhood. Recent advances in treatments including hematopoietic cell transplantation (HCT) and enzyme replacement therapy (ERT) have been helping children with these disorders live into adulthood. The long term-course of the disease is now unknown. Unfortunately, severe skeletal disease persists for most individuals despite current therapies. This is a longitudinal study of 50 children and adults with MPS I, II, and VI. Study participants will be evaluated every year for up to 3 years. The purpose of this study is to document the progression of skeletal disease and identify biomarkers that either predict disease severity or could be used as therapeutic targets. This information is needed to: <ul> <li>determine long-term benefits and limitations of current treatments including HCT or ERT</li> <li>direct development of further treatment options</li> <li>improve clinical care for children affected by the disorder</li> </ul>

Longitudinal Study of Bone and Endocrine Disease

Elevated TNF-α is associated with pain and physical disability in mucopolysaccharidosis types I, II, and VI.

Low bone mineral content and challenges in interpretation of dual-energy X-ray absorptiometry in children with mucopolysaccharidosis types I, II, and VI.

Effect of recombinant human growth hormone on changes in height, bone mineral density, and body composition over 1-2 years in children with Hurler or Hunter syndrome.

Bone mineral deficits in recipients of hematopoietic cell transplantation: the impact of young age at transplant