What is achondroplasia?

Achondroplasia, also known as achondroplastic dwarfism or ACH, is a rare disorder characterized by short stature, a large head, and short arms and legs. It is the most common type of skeletal dysplasia, the umbrella term that identifies hundreds of conditions, and occurs in about one in 15,000 to 35,000 births.

It is not known what causes achondroplasia, treatment options are limited, and there is no known cure — however, unless an individual experiences extreme complications from the condition, life expectancy is not impacted. Below, we will be discussing an overview of the condition, how it is diagnosed, developed, and treated, and how clinical trials can help researchers understand it better.

An overview of achondroplasia

Achondroplasia is a genetic condition that begins during fetal development, at the stage where cartilage tissue typically turns into bone. Fetuses with achondroplasia do not effectively convert much of the cartilage in the arms and legs into bones, which causes the upper sections of the arms and legs to be shorter than the lower portions of those limbs.

Common characteristics of individuals with achondroplasia include shorter than average arms and legs (particularly the upper arms and thighs), limited range of elbow motion, and an enlarged head. Without treatment, the average height for an adult male is 4’4” and the average height for an adult female is 4’1”.

Achondroplasia treatment options

While there is no way to prevent achondroplasia, the options for treatment have expanded in recent years for younger individuals living with the condition. In 2021, a medication was approved for children five and older that promotes growth while the growth plates are still open.

Outside of this, managing the condition and its associated health problems is the recommended course of action — obesity, recurrent ear infections, and a narrowing of the spinal canal are all commonly experienced by diagnosed individuals. There is no cure for achondroplasia, but those with ACH are typically able to live a full and healthy life as long as they work closely with their medical team to address any secondary complications.

How is achondroplasia diagnosed?

Generally, achondroplasia will be diagnosed before birth during an ultrasound, but it can also be diagnosed after birth during a physical examination. For parents who are at an increased risk of having a child with achondroplasia, DNA testing is available to confirm ultrasound findings.

How is achondroplasia inherited?

Though achondroplasia can be inherited from a parent with the condition, it is most commonly caused by a new genetic mutation, meaning it can affect anyone. Parents have a 50% chance of passing on the gene to their child, but about 80% of all cases occur when neither parent has achondroplasia and are caused by a new genetic mutation.

Resources for achondroplasia

There are many resources available for individuals living with achondroplasia as well as their caregivers. There are several patient advocacy organizations listed below that offer educational resources, group support, and more. Some groups of note include:

Though progress has been made in the diagnosis and treatment of achondroplasia, there are still many things that researchers do not understand about this condition. For that reason, clinical trials are ongoing to help scientists better understand, diagnose, and treat individuals who live with it. Learn more about clinical trials and see studies available in your area using the button below.