Achondroplasia

Summary about Disease


Achondroplasia is a genetic bone growth disorder that causes disproportionate dwarfism. It's characterized by shortened limbs, a relatively large head, and specific facial features. It's the most common form of dwarfism.

Symptoms


Shortened arms and legs, with the upper arms and thighs being particularly short

Large head with a prominent forehead

Flattened bridge of the nose

Small fingers

Spinal stenosis (narrowing of the spinal canal) in adulthood

Hypotonia (decreased muscle tone) in infancy

Delayed motor skills (e.g., sitting, walking)

Bowed legs

Hydrocephalus (fluid buildup in the brain) can occur, but is rare.

Causes


Achondroplasia is caused by a mutation in the FGFR3 gene (fibroblast growth factor receptor 3). This gene is involved in bone and brain tissue maintenance and growth. In most cases, it is a new (de novo) mutation. In some cases, it can be inherited from a parent with achondroplasia. If one parent has the mutation there is a 50% chance of inheritance, if both parents have the mutation the chances are 75% of inheritance, 25% the baby will not have Achondroplasia and 50% it will have Achondroplasia.

Medicine Used


Vosoritide (Voxzogo): A C-type natriuretic peptide (CNP) analog used to treat achondroplasia in children whose growth plates are still open. It promotes bone growth. Other medications address complications:* Pain relievers, antibiotics for ear infections, treatments for spinal stenosis, etc.

Is Communicable


No, achondroplasia is not communicable. It is a genetic disorder, not an infectious disease.

Precautions


There are no precautions to prevent achondroplasia since it is a genetic condition. Genetic counseling is recommended for individuals with achondroplasia who are planning to have children. Monitoring for complications like spinal stenosis and hydrocephalus is important for affected individuals.

How long does an outbreak last?


Achondroplasia is not an outbreak; it is a genetic condition that is present from birth. There is no duration in the sense of an infectious outbreak. It is a lifelong condition.

How is it diagnosed?


Physical Examination: Characteristic features are usually apparent at birth.

X-rays: Reveal distinctive bone abnormalities.

Genetic Testing: Confirms the diagnosis by identifying the FGFR3 mutation.

Prenatal Ultrasound: Can sometimes detect skeletal abnormalities before birth.

Timeline of Symptoms


At Birth: Short limbs, large head, flattened nasal bridge.

Infancy: Hypotonia, delayed motor milestones.

Childhood: Continued disproportionate growth, bowed legs.

Adulthood: Spinal stenosis, potential for other orthopedic problems.

Important Considerations


Comprehensive Care: Individuals with achondroplasia require ongoing medical care, including monitoring for complications and orthopedic management.

Psychosocial Support: Dealing with dwarfism can present psychosocial challenges. Support groups and counseling can be beneficial.

Adaptive Equipment: Modifications to homes and schools may be necessary to accommodate shorter stature.

Life Expectancy: With proper medical care, individuals with achondroplasia typically have a normal life expectancy.