The clinical picture of achondroplasia
The main feature in people with achondroplasia is their short stature (usually under 4 feet, 6 inches) due to short arms and legs.
You can see also in these people:
- Macrocephaly (large head) with frontal bossing (forehead protruding)
- Depressed nasal bridge
- Abdomen and buttocks protrude due to the inward curvature of the vertebral column
- The vertebral column shows curvatures, either kyphosis or lordosis.
- Spinal stenosis: Narrowing of the vertebral column
- You can see tiny hands that may show a “trident” or three-pronged position when extended due to the diversion between the ring and the middle fingers.
- Reduced arms and legs (notably the upper arm and thigh)
- Bowed legs
- Decreased muscle tone, which affects the motor power of the patient
In infants, we may see the following:
- Infants with achondroplasia may have a “dome-like” (vaulted) skull with a prominent forehead.
- We may find an excessive accumulation of fluid around the brain (hydrocephalus), but it is uncommon.
- We may observe Low muscle tone (hypotonia) and delayed developmental motor functions in these affected infants.
