Some cases of CJD are inherited. This means that a change in the gene which controls the configuration of prion proteins changes (or mutates) and can therefore cause prion proteins to form differently. If the genetic information for prion proteins is mutated in an individual’s egg or sperm cells, this mutation can be then passed to a foetus. There are several mutations which can occur and have been identified in the prion gene. The differing mutations can affect the frequency of the disease within a family and also the symptoms which arise. A mutation in the prion protein gene however does not necessarily mean that the person will develop CJD.
