Achondroplasia

What are the features of achondroplasia?

Achondroplasia is a condition one is born with. It can sometimes be diagnosed before birth by antenatal ultrasound scans in the third trimester.

The severity of symptoms may vary from person to person, even among family members with achondroplasia.

The main features include:

• Short stature. The average adult height is approximately 120-135 cm
• Facial features. Larger head size with a prominent forehead, and flattened nose bridge
• Rhizomelic shortening. Short extremities with shortened bones in upper arms and thighs
• Limited elbow extension. Inability to fully straighten elbows
• Short fingers with trident appearance of hands and short toes. Short fingers with increased space between the third and fourth fingers
• Bow legs. Outward curving of the bones, between the thighs and ankles
• Kyphosis. Curving of the upper spine due to reduced muscle tone, typically in infancy and which improves once the child begins walking
• Lumbar lordosis. Curving of the lower spine which commonly develops after the child starts walking

Other medical concerns

The following issues can also be present in individuals with achondroplasia, and need to be monitored for and treated if present:

• Craniocervical junction constriction. Narrowing of the junction between the skull and neck spinal bone
• Spinal stenosis. Due to small vertebral canals (spaces inside the spinal bones) leading to spinal cord compression
  
• Hydrocephalus. Build-up of fluid in the brain
• Regular ear infections due to middle ear dysfunction
• Obstructive sleep apnoea. No breathing for short periods of time when asleep
• Restrictive pulmonary disease. Due to small chest causing smaller lung volumes
• Obesity
• Dental problems