Risk factors

Most cases of Creutzfeldt-Jakob disease occur for unknown reasons, and no risk factors can be identified. However, a few factors seem to be associated with different kinds of CJD.

Age: Sporadic CJD tends to develop later in life, usually around the age of 60. Onset of familial CJD occurs only slightly earlier. On the other hand, vCJD has affected people at a much younger age, usually in their late 20s.

Genetics: People with familial CJD have a genetic mutation that causes the disease. The disease is inherited in an autosomal dominant fashion, which means you need to inherit only one copy of the mutated gene, from either parent, to develop the disease. If you have the mutation, the chance of passing it on to your children is 50 percent. Genetic analysis in people with iatrogenic and variant CJD suggest that inheriting identical copies of certain variants of the prion gene may predispose a person to developing CJD if exposed to contaminated tissue.

Contaminated tissue: People who've received human growth hormone derived from human pituitary glands or who've had dura mater grafts may be at risk of iatrogenic CJD. The risk of contracting vCJD from eating contaminated beef is difficult to determine. In general, if countries are effectively implementing public health measures, the risk is virtually nonexistent.