Achondroplasia

Prion Pathogens

ALteration of the PrP Gene

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• Individuals with Achondroplasia suffer from a mutation in the fibroblast growth factor reptor 3 gene (FGFR3), which affects bone growth bone growth, creating disproportioned dwarsism.

• Bone tissue within the cartillage does not grow properly creating short extremities.

Frequencies

1 in 25,000 births have the disease. 350,000+ people in the world have Anchondroplaisa

CAUSES

• The cartilage is unable to develop in the bones of the arms and legs. Mutations in the FGFR3 gene on chromosome 4p16.3 are responsible for protein altering .

• The protein becomes damage or absent, decreasing growth factors in the chondrocytes of growth plates in the long bones.

• FGF gene connects externally and send signals to the inside of the cell to stop bone growth.

As shown is the figure above, only one copy from one parent is needed to have a 50% chance of having a child with anchondroplasia.

Symptoms with and without treatment

Large head Loose joints Spinal stenosis Crowded teeth Flat feet Short fingers Undeveloped facial features Bowed or short limbs Hydrocephalus Recurrent ear infections

25%

If both parents have the disease the child has a 25% chance of being normal.

Treatment/Life Expectancy

Diagnosis

• Prenatal ultrasound.
• Genetic testing deriving the FRFGR3 gene from the fetus in the womb.
• Physical exam and X-ray at birth.
• Blood test at birth.

• There is no cure for Anchondroplasia.
• Treatments include leg braces, surgery, ear tubes, antibiotics for hydrocephalus, and growth hormones.

• Life expectancy with and without treatment is shorter than the average height human

Studies used with Mus Musculus

"Bowed" lower extremities of a child with Achondroplasia.

In the image above a point mutation was created in the FRFG3 gene of control group. The results were overgr owth of long bones and growth plates.