Achondroplasia is a type of rare genetic bone disorder. Achondroplasia is the most common type of these disorders. It causes the strong, flexible tissue called cartilage to not be made into bone as normal. This causes a series of signs, such as short arms and legs and a large head. This condition used to be called dwarfism. A boy with the condition will reach an average adult height of about 4 feet, 4 inches (52 inches). A girl with the condition will reach an average adult height of about 4 feet, 1 inch (49 inches). People with achondroplasia have normal intelligence and normal lifespan.
Achondroplasia is a genetic disease. It is an autosomal dominant disease. This means that only one abnormal gene inherited from one parent leads to the condition. Most cases of achondroplasia are from a new gene mutation in families. This means the parents are average height and do not have the abnormal gene.
Having a parent with achondroplasia increases the risk of being born with the condition. But most babies born with the condition do not have a family history of it.
Signs can occur a bit differently in each child. They can include:
The signs of achondroplasia can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.
Achondroplasia can be diagnosed before birth by fetal ultrasound. This test uses sound waves and a computer to create images of the baby growing in the womb. DNA testing can also be done before birth to confirm fetal ultrasound results.
The condition can also be diagnosed after birth with a physical exam. You can track your child's growth for any signs of slowing. In particular, note if it's different from how your other children grew.
There is no treatment for changing the condition. But different kinds of treatment can be done to help relieve problems caused by the condition.
Surgery may be done to:
Other treatments may include:
Treatment with growth hormone does not largely affect the height of a person with achondroplasia.
Health problems are common in children and adults with achondroplasia. Not all of the below problems occur in every child with achondroplasia. Each problem can be addressed by your child's healthcare team. Problems may include:
A child with the condition may also have small vertebral canals. These are the spaces inside the spinal bones. This may lead to spinal cord compression as a child gets older. In rare cases, a child with achondroplasia may die suddenly in infancy or early childhood during sleep because of compression of the upper end of the spinal cord. Compression in this area causes problems with breathing.
Most cases occur in families with no history of the condition, and can't be prevented. If a parent or parents have achondroplasia, a genetic counselor can give you information about the possibility of passing the condition on to your child.
Keep all well-child appointments so your child's health can be regularly monitored. Keep an ongoing list of questions and bring them with you to your child's appointments.Living with achondroplasia not only means adapting to being short in a world built mostly for taller people. It also means watching for possible complications, and managing problems that occur. A healthcare team that has worked with the condition can help you manage your child's physical and emotional needs. Groups such as Little People of America can give support and information to your family and your child.
Your child will also have special protection in the public education system. The Americans with Disabilities Act and Section 504 of the Rehabilitation Act of 1973 provide these protections. Review the online resources and check with your state or local school board about when and how to ask for classroom and other school changes your child may need. You will become your child's most important supporter in the school system.
If your child has achondroplasia, call the healthcare provider if your child has:
Tips to help you get the most from a visit to your child’s healthcare provider: