Achondroplasia disease is an inherited bone growth disorder that affects 1 out of 15,000 to 40,000 births. Characteristics of a person with the condition include: a short stature with proportionately short arms and legs, a large head, a prominent forehead, and a flattened bridge of the nose. While there is no cure for achondroplasia disease, symptoms and associated complications can be managed.
Achondroplasia Disease: An Overview
Achondroplasia disease is one of the most common causes of dwarfism. The term is a Greek word that means "without cartilage formation." Characteristics of a person with achondroplasia include:
- A short stature with proportionately short arms and legs
- A large head
- A prominent forehead
- A flattened bridge of the nose.
Achondroplasia disease is the most common type of short-limbed dwarfism. This condition affects 1 in 15,000 to 40,000 births.
Cause of Achondroplasia Disease
Most people with achondroplasia disease have average-size parents, which means that the condition is caused by a new mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. Although the gene is believed to be responsible for achondroplasia, scientists do not know why this mutation occurs.
(Click FGFR3 Gene for more information about the gene that can cause achondroplasia.)
Achondroplasia disease can also be inherited in an autosomal dominant pattern, which means that one copy of the altered gene in each cell is sufficient to cause the disorder. In these cases, one of the parents with achondroplasia passes on the FGFR3 gene to the child.
If one parent has achondroplasia, children have a 50 percent chance of inheriting the FGFR3 gene. If both parents have achondroplasia, children have a one in four chance of inheriting the gene from both parents. Newborns who inherit both genes are considered to have a severe form of achondroplasia, where survival is usually less than 12 months after birth.
(Click Cause of Achondroplasia for more information.)