Jansen's metaphyseal chondrodysplasia

Jansen's metaphyseal chondrodysplasia
Jansen's metaphyseal chondrodysplasia
Classification and external resources
ICD-9 756.9
OMIM 156400
DiseasesDB 31669

Jansen's metaphyseal chondrodysplasia or JMC is a disease that results from ligand-independent activation of the type 1 of the parathyroid hormone receptor (PTHR1), due to one of three reported mutations (activating mutation).

JMC is extremely rare and as of 2007 there are less than 20 reported cases worldwide.

Contents

Presentation

Blood levels of parathryoid hormone (PTH) are undetectable, but the mutation in the PTHR1 leads to auto-activation of the signaling as though the hormone PTH was present. Severe JMC produces a dwarfing phenotype, or short stature. Examination of the bone reveals normal epiphyseal plates but disorganized metaphyseal regions. Hypercalcemia (elevated levels of calcium in the blood) )and hypophosphatemia (reduced blood levels of phosphorus), and elevated urinary calcium and phosphorus are generally found in JMC. The absence of hypercalcemia does not eliminate the disease from consideration.

Physical irregularities often associated with Jansen's include: prominent or protruding eyes, a high arched palate, micrognathia or abnormal smallness of the jaws - particularly the lower (mandible) jaw, choanal stenosis, wide cranial sutures and irregular formation of the long bones which can resemble rickets. Nephrocalcinosis (accumulation of calcium in the interstitum of the kidney) is seen commonly as well.

Treatment

There is no known treatment at present, although some investigators have tried to lessen the hypercalcemia with various forms of bisphosphonates.

Note

There is one known family in which the disease was transmitted mother to daughter.

Synonyms

  • Murk Jansen Type Metaphyseal Chondrodysplasia
  • Jansen Metaphyseal Dysostosis
  • Jansen Disease
  • JMC

Eponym

It is named for Murk Jansen.[1][2]

References

  1. ^ Jansen, M. Ueber atypische Chondrodystrophie (Achondroplasie) und ueber eine noch nicht beschriebene angeborene Wachstumsstoerung des Knochensystems: Metaphysaere Dysostosis. Z. Orthop. Chir. 61: 253-286, 1934.
  2. ^ Silverthorn KG, Houston CS, Duncan BP (1987). "Murk Jansen's metaphyseal chondrodysplasia with long-term followup". Pediatric radiology 17 (2): 119–123. doi:10.1007/BF02388087. PMID 3562109. 

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Metaphyseal dysplasia — Classification and external resources ICD 10 Q78.5 ICD 9 756.9 …   Wikipedia

  • Chondrodysplasia punctata — Classification and external resources ICD 10 Q77.3 DiseasesDB 32527 …   Wikipedia

  • Jansen — may refer to:;People *Jansen (surname);Places * Jansen, Saskatchewan, Canada * Jansen, Colorado, United States * Jansen, Nebraska, United States;Other uses * Jansen AG, Swiss company which produces steel and plastic pipes, as well as profiles *… …   Wikipedia

  • metaphyseal dysostosis — a skeletal abnormality in which the epiphyses are normal, or nearly so, and the metaphyseal tissues are replaced by masses of cartilage, producing interference with enchondral bone formation, and expansion and thinning of the metaphyseal cortices …   Medical dictionary

  • Rhizomelic chondrodysplasia punctata — Classification and external resources ICD 10 Q77.3 ICD 9 277.86 …   Wikipedia

  • Parathyroid hormone receptor 1 — is a parathyroid hormone receptor It is encoded by the gene PTHR1 . It is a receptor for parathyroid hormone (PTH) and for parathyroid hormone like hormone (PTHLH).FunctionIt is the classical PTH receptor, is expressed in high levels in bone and… …   Wikipedia

  • Achondroplasia — Classification and external resources Jason Acuña, alias Wee Man , a star of Jackass …   Wikipedia

  • Osteopetrosis — (Malignant) Classification and external resources X ray of the pelvis of a patient with osteopetrosis, adult onset form (Albers Schonberg disease). Note the dense bones. ICD …   Wikipedia

  • Thanatophoric dysplasia — Classification and external resources ICD 10 Q77.1 OMIM 187600 DiseasesDB …   Wikipedia

  • Conradi–Hünermann syndrome — Conradi Hünermann syndrome Classification and external resources ICD 10 Q77.3 ICD 9 756.59 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”