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Start free with EleplanAchondroplasia
ORPHA:15Disease
What it is
A primary bone dysplasia with micromelia characterized by rhizomelia, exaggerated lumbar lordosis, brachydactyly, and macrocephaly with frontal bossing and midface hypoplasia.
Key facts
- Prevalence
- 1-9 / 100 000 (at birth)
- Age of onset
- Antenatal, 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
Very common80–99%
5Common30–79%
23- Abnormal midface morphology
- Anteverted nares
- Brachydactyly
- Central sleep apnea
- Cervical spinal canal stenosis
- Depressed nasal bridge
- Floppy infant
- Frontal bossing
- Functional abnormality of the middle ear
- Hearing impairment
- Hip joint hypermobility
- Knee joint hypermobility
- Limited elbow extension
- Lumbar hyperlordosis
- Macrocephaly
- Obstructive sleep apnea
- Parietal bossing
- Short long bone
- Short middle phalanx of finger
- Short nasal bridge
- Short proximal phalanx of finger
- Spinal canal stenosis
- Trident hand
Sometimes5–29%
10- Abnormality of the wing of the ilium
- Acanthosis nigricans
- Flat acetabular roof
- Hypoxemia
- Narrow greater sciatic notch
- Obesity
- Restrictive ventilatory defect
- Rhizomelia
and 2 more in this range
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.
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