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CHST3-related skeletal dysplasia
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Reviewed October 2012
What is CHST3-related skeletal dysplasia?
CHST3-related skeletal dysplasia is a genetic condition characterized by bone and joint abnormalities that worsen over time. Affected individuals have short stature throughout life, with an adult height under 4 and a half feet. Joint dislocations, most often affecting the knees, hips, and elbows, are present at birth (congenital). Other bone and joint abnormalities can include an inward- and upward-turning foot (clubfoot), a limited range of motion in large joints, and abnormal curvature of the spine. The features of CHST3-related skeletal dysplasia are usually limited to the bones and joints; however, minor heart defects have been reported in a few affected individuals.
Researchers have not settled on a preferred name for this condition. It is sometimes known as autosomal recessive Larsen syndrome based on its similarity to another skeletal disorder called Larsen syndrome. Other names that have been used to describe the condition include spondyloepiphyseal dysplasia, Omani type; humero-spinal dysostosis; and chondrodysplasia with multiple dislocations. Recently, researchers have proposed the umbrella term CHST3-related skeletal dysplasia to refer to bone and joint abnormalities resulting from mutations in the CHST3 gene.
Read more about Larsen syndrome.
How common is CHST3-related skeletal dysplasia?
The prevalence of CHST3-related skeletal dysplasia is unknown. More than 30 affected individuals have been reported.
What genes are related to CHST3-related skeletal dysplasia?
As its name suggests, CHST3-related skeletal dysplasia results from mutations in the CHST3 gene. This gene provides instructions for making an enzyme called C6ST-1, which is essential for the normal development of cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Mutations in the CHST3 gene reduce or eliminate the activity of the C6ST-1 enzyme. A shortage of this enzyme disrupts the normal development of cartilage and bone, resulting in the abnormalities associated with CHST3-related skeletal dysplasia.
Read more about the CHST3 gene.
How do people inherit CHST3-related skeletal dysplasia?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of CHST3-related skeletal dysplasia?
These resources address the diagnosis or management of CHST3-related skeletal dysplasia and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about CHST3-related skeletal dysplasia?
You may find the following resources about CHST3-related skeletal dysplasia helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for CHST3-related skeletal dysplasia?
What if I still have specific questions about CHST3-related skeletal dysplasia?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding CHST3-related skeletal dysplasia?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (7 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.