Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism.

Alternative Names of Achondroplasia are: Dwarfism.

Complications of Achondroplasia

• Clubbed feet.
• Fluid build up in the brain (hydrocephalus).

Causes of Achondroplasia

• Achondroplasia is one of a group of disorders called chondrodystrophies or osteochondrodysplasias.
• Achondroplasia may be inherited as an autosomal dominant trait, which means that if a child gets the defective gene from one parent, the child will have the disorder. If one parent has achondroplasia, the infant has a 50% chance of inheriting the disorder. If both parents have the condition, the infant's chances of being affected increase to 75%.
• However, most cases appear as spontaneous mutations. This means that two parents without achondroplasia may give birth to a baby with the condition.

Signs & Symptoms of Achondroplasia

Typical appearance of achondroplastic dwarfism is apparent at birth:

1. Short stature
2. Short limbs, proximal extremity (upper arm and thigh)
3. Large appearing head
4. Skeletal (limb) abnormalities
5. Abnormal hand appearance (trident hand) with persistent space between the long and ring fingers
6. Marked kyphosis and lordosis (spine curvatures)
7. Waddling gait
8. Prominent (conspicuous) forehead (frontal bossing)
9. Head appears disproportionately large for body
10. Hypotonia
11. Polyhydramnios
12. Bowed legs

Diagnosis of Achondroplasia

• During pregnancy, a prenatal ultrasound may show excessive amniotic fluid surrounding the unborn infant.
• Examination of the infant after birth shows increased front-to-back head size. There may be signs of hydrocephalus ("water on the brain").
• X-rays of the long bones can reveal achondroplasia in the newborn.

Treatments of Achondroplasia

There is no specific treatment for achondroplasia. Related abnormalities, including spinal stenosis and spinal cord compression, should be treated when they cause problems.

Prevention of Achondroplasia

Genetic counseling may be helpful for prospective parents when one or both have achondroplasia. However, because achondroplasia most often develops spontaneously, prevention is not always possible.

When to seek Medical Advice
If there is a family history of achondroplasia and you plan to have children, you may find it helpful to speak to your health care provider.