Achondroplasia is an inherited disorder of bone growth. It is
one of the group of disorders that are collectively called chondrodystrophies or
The disorder causes a type of dwarfism that is recognized by its characteristic normal
to large-sized head, shortened arms and legs (especially the upper arm and thigh), a
normal-sized trunk, and waddling gait. Achondroplasia is the most common type of dwarfism.
Achondroplasia is inherited as an autosomal dominant trait. However, the majority of
cases, approximately 80%, appear as spontaneous mutations. 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%