User:SaswatPanda/Genetic Basis of the Osteochondrodysplasias

Osteochondrodysplasias are a heterogenous group of disorders characterized by abnormal growth and remodeling of cartilage and bone, affecting about 2 to 4.7 per 10,000 individuals.[1] Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) and cartilage("chondro").[2][3]

History

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Types

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Achondroplasia

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Achondroplasia is a type of autosomal dominant genetic disorder that is a common cause of dwarfism. Achondroplastic dwarfs have short stature, with an average adult height of 131 cm (4 feet, 3.8 inches) for males and 123 cm (4 feet, 0.6 inches) for females.

The prevalence is approximately 1 in 25,000.[4]

Genetic Basis

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Kyle Pacek, an American actor has Achondroplasia, a type of dwarfism. He is 4'6" tall.

Mutations in the FGFR3 gene cause achondroplasia. The FGFR3 gene provides instructions for making proteins which maintain and evelop bone and brain tissues.[5] Researchers believe that these mutations cause the FGFR3 protein is overly active in cases of achondroplasia, and this causes disturbances in bone and cartilage growth.[6]

Presentation
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Achondroplasia is a form of short-limbed dwarfism, it literally means "without cartilage formation."


Cleidocranial dysostosis

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Cleidocranial dysostosis is a general skeletal condition named for the collarbone (cleido-) and cranium deformities which people with it often have. Common features include:


Fibrous dysplasia

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Fibrous dysplasia causes bone thinning[7] and growths or lesions in one or more bones of the human body.

These lesions are tumor-like growths that consist of replacement of the medullary bone with fibrous tissue, causing the expansion and weakening of the areas of bone involved. Especially when involving the skull or facial bones, the lesions can cause externally visible deformities. The skull is often, but not necessarily, affected, and any other bone(s) can be involved.


Langer-Giedion syndrome

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Langer-Giedion syndrome is a very rare genetic disorder caused by a deletion of chromosomal material. Diagnosis is usually made at birth or in early childhood.

The features associated with this condition include mild to moderate learning difficulties, short stature, unique facial features, small head and skeletal abnormalities including bony growths projecting from the surfaces of bones.


Mafucci syndrome

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Maffucci syndrome is a sporadic disease characterized by the presence of multiple enchondromas associated with multiple simple or cavernous soft tissue hemangiomas. Also lymphangiomas may be apparent.

Patients are normal at birth and the syndrome manifests during childhood and puberty. The enchondromas affect the extremities and their distribution is asymmetrical.


Osteosclerosis

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Osteosclerosis, an elevation in bone density,[8] is normally detected on an X-ray as an area of whiteness, and is where the bone density has significantly increased. Localized osteosclerosis can be caused by injuries that compress the bone, by osteoarthritis, and osteoma.


Other

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References

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  1. ^ Baitner, A. C., Maurer, S. G., Gruen, M. B., & Di Cesare, P. E. (2000). The genetic basis of the osteochondrodysplasias. Journal of Pediatric Orthopaedics, 20(5), 594-605.
  2. ^ "Medcyclopaedia - Osteochondrodysplasia". Archived from the original on 2012-02-05.
  3. ^ Zelzer, E., & Olsen, B. R. (2003). The genetic basis for skeletal diseases. Nature, 423(6937), 343-348.
  4. ^ Wynn J, King TM, Gambello MJ, Waller DK, Hecht JT (2007). "Mortality in achondroplasia study: A 42-year follow-up". Am. J. Med. Genet. A. 143 (21): 2502–11. doi:10.1002/ajmg.a.31919. PMID 17879967.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ Rousseau, F., Bonaventure, J., Legeai-Mallet, L., Pelet, A., Rozet, J. M., Maroteaux, P., ... & Munnich, A. (1994). Mutations in the gene encoding fibroblast growth factor receptor-3 in achondroplasia.
  6. ^ Shiang, R., Thompson, L. M., Zhu, Y. Z., Church, D. M., Fielder, T. J., Bocian, M., ... & Wasmuth, J. J. (1994). Mutations in the transmembrane domain of FGFR3 cause the most common genetic form of dwarfism, achondroplasia. Cell, 78(2), 335-342.
  7. ^ "fibrous dysplasia of bone" at Dorland's Medical Dictionary
  8. ^ "Medcyclopaedia - Osteosclerosis". Retrieved 2007-12-23.
  9. ^ Marks, Dawn B.; Swanson, Todd; Sandra I Kim; Marc Glucksman (2007). Biochemistry and molecular biology. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. ISBN 0-7817-8624-X.{{cite book}}: CS1 maint: multiple names: authors list (link)