Achondroplasia: Causes, Symptoms, Diagnosis And Treatment

Achondroplasia is a rare genetic bone disorder characterized by short-limbed dwarfism ^[1] . In Achondroplasia, there is an abnormal cartilage formation that affects the skeletal growth of a person and makes them a dwarf with short limbs and large head.

The average height of achondroplasia adult males is 4 feet, 4 inches while females have 4 feet, 1 inch ^[2] . Their intelligence level is normal and the dwarfism trait in parents often used to pass to their children. However, it can also occur to people who do not have a history of dwarfism in their family due to some gene mutation. Achondroplasia is among the oldest known birth defects and its ratio is 1 in 15000 - 35000 births.

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What Causes Achondroplasia

Achondroplasia is referred to as an autosomal dominant disease. It can affect both males and females. A gene named FGFR3 ^[3] is responsible for the development of bone and brain tissues in our body. Due to two specific kind of mutations in that gene, bone development process gets disturbed leading a person to achondroplasia.

If at least one defective FGFR3 gene passes to the child from either of the parents, the child can develop the trait of dwarfism. However, a report says that 80% of people have developed the condition due to a new gene mutation in the family who don't have a history of dwarfism.

Symptoms Of Achondroplasia

Every child with achondroplasia may experience different symptoms. However, common symptoms of the condition are as follows:

1. Short arms, legs and fingers
2. Short stature than average people ^[4]
3. Large heads in comparison to their body
4. Bowed lower legs ^[2]
5. Lordosis, a condition characterized by the curved lower spine
6. Short and broad flat feet
7. Trident hand, a large space between the middle and ring fingers
8. Apnea, slow breathing or sudden stop of breathing
9. Obesity
10. An ear infection that occurs often ^[5]
11. Delay in motor functions
12. Hydrocephalus, water in the brain ^[6]

Diagnosis Of Achondroplasia

Achondroplasia can be diagnosed by two methods which are as follows:

• Diagnosis during pregnancy: During an ultrasound, any abnormalities (large head or a short limb) in the foetus can be identified easily by a medical expert. If they suspect the condition, genetic tests are ordered by taking an amniotic fluid sample from the mother's womb ^[7] .
• Diagnosis after pregnancy: If a child is born with achondroplasia, the condition can easily be identified visually by a medical expert. X-ray test is ordered to find out the length of the child's bones^[8] .

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Treatment Of Achondroplasia

People with achondroplasia can live a normal life. However, children with the condition need a lot of medical attention and care for their physical and mental growth. The treatments are as follows:

• Surgery of the spinal stenosis, in case it is too narrow ^[9]
• Surgery in case of spinal cord compression
• Surgery to correct the bowed legs
• Surgery to prevent hydrocephalus, water in the brain ^[6]
• Antibiotics for ear infection ^[5]
• Straightening the teeth in case of dental crowding^[10]
• Growth hormone, but this is not yet proved to be effective