Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.
Start free with EleplanPseudoachondroplasia
ORPHA:750Disease
Also called Pseudoachondroplastic dysplasia · Pseudoachondroplastic spondyloepiphyseal dysplasia
What it is
Pseudoachondroplasia is characterized by severe growth deficiency and deformations such as bow legs and hyperlordosis.
Key facts
- Prevalence
- 1-9 / 100 000
- Age of onset
- Infancy, Neonatal
- Inheritance
- Autosomal dominant
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Common30–79%
20- Abnormal form of the vertebral bodies
- Arthralgia
- Brachydactyly
- Delayed epiphyseal ossification
- Distal joint hypermobility
- Generalized joint hypermobility
- Increased laxity of fingers
- Irregular epiphyses
- Knee joint hypermobility
- Limb undergrowth
- Lumbar hyperlordosis
- Metaphyseal irregularity
- Metaphyseal widening
- Osteoarthritis
- Platyspondyly
- Shortening of all metacarpals
- Short long bone
- Short phalanx of finger
- Waddling gait
- Wind-swept deformity of the knees
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
Powered by Eleplan
A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.
Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.