What are prions (in relation to variant CJD)?
The agent that causes variant CJD is believed to be an abnormal form of a protein, known as a prion. Prions are normal cellular proteins that are present in many organs and tissues, including the brain, spinal cord and eyes of healthy humans and animals. The abnormal form of prion causes surrounding proteins to change their shape. The abnormal protein collects in central nervous tissue and by an unknown mechanism causes the nerve cells to die. This results in the characteristic holes in the brain tissue that can be seen under the microscope.
