Jansen Type Metaphyseal Chondrodysplasia
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Jansen Type Metaphyseal Chondrodysplasia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Synonyms Back to top
- Murk Jansen Type Metaphyseal Chondrodysplasia
- Jansen Metaphyseal Dysostosis
- Jansen Disease
Disorder Subdivisions Back to top
General Discussion Back to top
Jansen type metaphyseal chondrodysplasia is an extremely rare progressive disorder in which portions of the bones of the arms and legs develop abnormally with unusual cartilage formations and subsequent abnormal bone formation at the large (bulbous) end portions (metaphyses) of these long bones (metaphyseal chondrodysplasia). As a result, affected individuals exhibit unusually short arms and legs and short stature (short-limbed dwarfism), findings that typically become apparent during early childhood. Abnormal cartilage and bone development may also affect other bones of the body, particularly those of the hands and feet (i.e., metacarpals and metatarsals). Infants with Jansen type metaphyseal chondrodysplasia may also have characteristic facial abnormalities and additional skeletal malformations. During childhood, affected individuals may begin to exhibit progressive stiffening and swelling of many joints and/or an unusual "waddling gait" and squatting stance. In addition, affected adults may eventually develop abnormally hardened (sclerotic) bones especially in the back of the head (cranial bones), which, in some cases, may lead to blindness and/or deafness. In addition, in some cases, affected individuals have abnormally high levels of calcium in the blood (hypercalcemia). The range and severity of symptoms may vary from case to case. Most cases of Jansen type metaphyseal chondrodysplasia occur randomly as the result of a spontaneous genetic change (i.e., new genetic mutation)
Resources Back to top
Human Growth Foundation
997 Glen Cove Avenue
Glen Head, NY 11545
6645 W. North Avenue
Oak Park, IL 60302
Little People of America, Inc.
250 El Camino Real
Tustin, CA 92780
NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases
One AMS Circle
Bethesda, MD 20892-3675
NIH/National Institute on Deafness and Other Communication Disorders
31 Center Drive, MSC 2320
Communication Avenue. Bethesda, MD 20892-3456
Coalition for Heritable Disorders of Connective Tissue (CHDCT)
4301 Connecticut Avenue, NW Suite 404
Washington, DC 20008
Craniofacial Foundation of America
975 East Third Street
Chattanooga, TN 37403
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
For a Complete Report Back to top
This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email firstname.lastname@example.org
Last Updated: 11/5/2008
Copyright 1997, 1998, 2004, 2005, 2008 National Organization for Rare Disorders, Inc.
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.