Creutzfeldt Jakob Disease - a Genetic Form

Backround: A genetic form of Creutzfeldt Jakob disease (CJD) is caused by a missense mutation in the prion protein (PRNP) gene. In a more than 70 per cent it is caused by E200K mutation, in this case the disease shows an incomplete penetration (63-75 %). Deciding factors of a manifestation of the disease in mutation bearers are not entirely clarified. Objective: To report a case of patient with genetic form of CJD. Methods: Detailed clinical and laboratory examinations and post mortem neuropathological examinations. Results: We documented a case of a forty nine years old woman treated for an invasive ductal carcinoma. She was treated by radiotherapy and a hormonal therapy. In next six months the patient developed symptoms like a progressive dementia, a tremor, a myoclonus in facial and lower limbs, extrapyramidal and cerebellar signs. We have considered a paraneoplastic syndrome due to oncology history or other neurodegenerative disease at first. However, we have expressed a suspicion of a prion disease in regard to other clinical signs and results of examinations. The prion disease was confirmed post mortem by neuropathological, immunohistochemical, immunological and molecular genetical examinations. There was proved a mutation E200K (GAG>AAG) in a heterozygous state. Conclusion: We documented a genetic form of CJD with the most common E200K mutation. Due to the incomplete penetration it is important to trace possible risk factors. With an exception of a lifestyle and infections, an oncology history is a very important factor affecting a manifestation of genetic CJD.