Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

*
(*) mandatory field





 

Other search option(s)

Pseudoachondroplasia

ORPHA750
Synonym(s) Pseudoachondroplastic dysplasia
Pseudoachondroplastic spondyloepiphyseal dysplasia
Prevalence -
Inheritance Autosomal dominant
Age of onset Infancy
Neonatal
ICD-10
  • Q77.8
OMIM
UMLS
  • C0410538
MeSH
  • C535819
MedDRA -

Summary

Pseudoachondroplasia is characterized by severe growth deficiency and deformations such as bow legs and hyperlordosis. Prevalence is estimated at around 1/60,000. The disorder is usually discovered during the second year of life with the onset of slow growth and walking difficulties. The short stature becomes more prominent with age and the hands and feet appear short and wide. Joint laxity is a general feature, but predominantly affects the hands. Defective epiphyseal growth causes early arthrosis. The limb deformation is caused by metaphyseal lesions. Transmission is autosomal dominant, but most isolated cases are due to de novo mutations. The disorder is caused by small mutations or deletions in the COMP gene (19p13.1) coding for the cartilage oligomeric matrix protein. Diagnosis is made on the basis of epiphyseal and metaphyseal anomalies detected on radiographs during the second year of life. The principle differential diagnosis is achondroplasia (see this term), but the craniofacial anomalies present in this disorder are absent in patients with pseudoachondroplasia and radiographic findings differ significantly. Forms of multiple epiphyseal dysplasia (see these terms) may also be included in the differential diagnosis. Genetic counseling may be proposed and the recurrence risk is 50%. Prenatal diagnosis is feasible if the mutation has been detected in an affected parent. Treatment is based on physiotherapy, management of the spinal deformation and corrective orthopedic surgery. Intensive physical activity should be avoided. The limb deformation should be corrected surgically at the end of the growth period. The final height prognosis is variable but the short stature may be moderately severe.

Expert reviewer(s)

  • Dr Martine LE MERRER

(*) Required fields.

Attention: Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.


Captcha image

Detailed information

Summary information
Article for general public
  • EN (2012)
Clinical genetics review
  • EN (2013)
Get Acrobat Reader
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.