What is Achondroplasia?
Achondroplasia is a genetic type of dwarfism. Dwarfism is a type of condition that causes a person to be of much shorter than average height. Achondroplasia is specifically a form of short-limbed dwarfism, which implies that people with the condition have shorter arms and legs than the general population. Achondroplasia is the most common form of dwarfism.
Genetic changes in the FGFR3 gene can lead to achondroplasia. People with achondroplasia have poor cartilage to bone conversion. Cartilage is the bendable, but strong material that makes up your ears and the tip of your nose. When babies are first developing, much of the skeleton is initially made of cartilage. This cartilage then needs to transform into bone in a process named ossification. When someone has a genetic change in the FGFR3 gene causing achondroplasia, ossification does not occur at the usual rate. This process is especially slowed in the legs and the arms. This causes people with achondroplasia to have shorter arms and legs than the average person.
To learn more about achondroplasia, contact a genetic counselor for more information. Use the Find a Genetic Counselor page at the National Society of Genetic Counselors' website to locate a genetic counselor near you.
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Are there other names for Achondroplasia?
Achondroplasia is also referred to as achondroplastic dwarfism. Sometimes it is abbreviated as "ACH". It should be noted that there are many terms out there that are used to describe not only people with achondroplasia, but also those with other forms of dwarfism. These include: dwarf, little person, LP, and person of short stature. It is very important to know that the term "midget" has fallen out of favor and should never be used to describe a person with achondroplasia or other type of dwarfism as it is considered an offensive term. If you want to know the proper names used to refer to achondroplasia, or if you want to know if a specific term can mean the same thing as achondroplasia, try looking at a reliable website such as Genetics Home Reference or the Little People of America website.
How common is achondroplasia?
The exact number of babies born with achondroplasia is not known. It is believed though that about every 1 in 15,000 to 1 in 40,000 babies born have achondroplasia.
Some populations appear to have a higher incidence of achondroplasia. For instance it is estimated to occur in about 1 case in 6400 births in Denmark and about 1 case in 10000 births in Latin America. No particular race has been documented to be more commonly affected.
- Defendi GL. Genetics of Achondroplasia. Medscape Reference. http://emedicine.medscape.com/article/941280-overview.