Achondroplasia is a genetic condition caused by a change in a gene that provides instructions for making a protein used to form bone and brain tissue. Achondroplasia is the most common form of inherited disproportionate short stature, or dwarfism. The word achondroplasia means “without cartilage formation.” Individuals with achondroplasia don’t convert cartilage into bone, particularly in the long bones. Achondroplasia is inherited. However, about 75% of people with achondroplasia have a new mutation and have average size parents.
About 1 in every 26,000-28,000 babies is born with achondroplasia.
Typically, individuals with achondroplasia have normal intelligence and a normal life span.
General Dwarfism Information
There are over 200 distinct types of dwarfism (generally a term used for a person 4’10’ or under). About 1 in every 10,000 babies is born with dwarfism. The most common dwarfing condition is achondroplasia.
However, there are many different reasons a person may be shorter than average. The most common reasons for short stature in children are familial short stature, a difference in the timing of growth (called constitutional growth delay) and, in girls, Turner syndrome. In addition, a person may be short for many other reasons (i.e. enzyme processing function disorder, kidney disease, etc.)
In general preferred terms are short stature, little person (LP), dwarfism, and for some people dwarf. However, as with all medical conditions, the preferred terminology is the person’s name.
This information was last updated in December, 2015.