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

Simple search

(*) mandatory field


Other search option(s)


Synonym(s) -
Prevalence 1-9 / 100 000
Inheritance Autosomal dominant
Age of onset Childhood
  • Q77.4
  • C0410529
MeSH -
  • 10020967


Disease definition

Hypochondroplasia is characterized by disproportionate short stature, mild lumbar lordosis and limited extension of the elbow joints.


Prevalence is estimated at around 1 in 33,000.

Clinical description

The clinical manifestations generally become apparent during childhood. Bowlegs may also be present. Facial dysmorphism, orthopedic malformations and neurologic problems are not features of hypochondroplasia. An association with intellectual deficit has been reported.


The disorder is caused by mutations in the fibroblast growth factor receptor-3 gene (FGFR3; 4p16.3).

Diagnostic methods

Typical radiological findings in hypochondroplasia include moderate narrowing of the interpeduncular distances, shortened tubular bones with distal lengthening of the fibula, and short and broad femoral necks.

Differential diagnosis

Hypochondroplasia closely resembles achondroplasia (also caused by mutations in the FGFR3 gene; see this term), although the short stature and skeletal disproportion are clearly less pronounced in hypochondroplasia and the two conditions can be differentiated on the basis of the milder radiological findings in hypochondroplasia.

Genetic counseling

The disorder is transmitted in an autosomal dominant manner.

Management and treatment

Treatment is symptomatic only.


Final adult height varies between 132 and 147 cm and life expectancy is normal.

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

Clinical genetics review
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.