SADDAN: Difference between revisions
No edit summary |
(No difference)
|
Revision as of 01:11, 7 July 2009
WikiDoc Resources for SADDAN |
Articles |
---|
Media |
Evidence Based Medicine |
Clinical Trials |
Ongoing Trials on SADDAN at Clinical Trials.gov Clinical Trials on SADDAN at Google
|
Guidelines / Policies / Govt |
US National Guidelines Clearinghouse on SADDAN
|
Books |
News |
Commentary |
Definitions |
Patient Resources / Community |
Directions to Hospitals Treating SADDAN Risk calculators and risk factors for SADDAN
|
Healthcare Provider Resources |
Continuing Medical Education (CME) |
International |
|
Business |
Experimental / Informatics |
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [1] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Overview
SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) is a rare inherited disorder of bone growth characterized by skeletal, brain, and skin abnormalities.
All people with this condition are extremely short with particularly short arms and legs. Other signs and symptoms include unusual bowing of the leg bones; a small chest with short ribs and curved collar bones; short, broad fingers; and folds of extra skin on the arms and legs. Structural abnormalities of the brain lead to seizures, profound developmental delay, and mental retardation. Acanthosis nigricans, a progressive skin disorder characterized by thick, dark, velvety skin, develops in infancy or early childhood. People with SADDAN often live into childhood and adulthood.
Many of the features of SADDAN are similar to those seen in other skeletal disorders, specifically achondroplasia and thanatophoric dysplasia.
Epidemiology
This disorder is very rare; it has been described in only a small number of individuals worldwide.
Genetics
Mutations in the FGFR3 gene cause SADDAN. The protein made by the FGFR3 gene is a receptor that plays a role in the development and maintenance of bone and brain tissue. A mutation in the gene may overactivate the receptor, which leads to disturbances in bone growth. Researchers have not determined how the mutation disrupts brain development or causes acanthosis nigricans.
SADDAN is considered an autosomal dominant disorder because one mutated copy of the FGFR3 gene in each cell is sufficient to cause the condition. The few described cases of SADDAN have been caused by new mutations in the FGFR3 gene. No individuals with this disorder are known to have had children; therefore, the disorder has not been passed to the next generation.
References
- Bellus GA, Bamshad MJ, Przylepa KA, Dorst J, Lee RR, Hurko O, Jabs EW, Curry CJ, Wilcox WR, Lachman RS, Rimoin DL, Francomano CA (1999). "Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN): phenotypic analysis of a new skeletal dysplasia caused by a Lys650Met mutation in fibroblast growth factor receptor 3". Am J Med Genet. 85 (1): 53–65. PMID 10377013.
- Cohen MM Jr (2002). "Some chondrodysplasias with short limbs: molecular perspectives". Am J Med Genet. 112 (3): 304–13. PMID 12357475.
- Vajo Z, Francomano CA, Wilkin DJ (2000). "The molecular and genetic basis of fibroblast growth factor receptor 3 disorders: the achondroplasia family of skeletal dysplasias, Muenke craniosynostosis, and Crouzon syndrome with acanthosis nigricans". Endocr Rev. 21 (1): 23–39. PMID 10696568.