The first case of variant Creutzfeldt-Jakob disease (vCJD) in a patient that is genetically different from all previous confirmed cases, has been reported in the UK. This suggests, as researchers have predicted, that the incubation of vCJD may take longer in certain groups of people. This 36 year old male patient was heterozygous at codon 129 (M/V) of the PRNP (prion protein), while all previous confirmed cases of vCJD have been homozygous for methionine (m/M) at codon 129.
vCJD is a rare neurological illness and is part of a group of diseases called prion diseases which affect humans and animals. Prion diseases are progressive, currently untreatable and ultimately fatal. Most vCJD cases are linked to consumption of cattle infected with bovine spongiform encephalopathy (BSE) but a few cases of transmission by blood transfusion have been reported. Cases of vCJD have been in decline since their peak around the year 2000. However, there has been concern that people who were exposed to the infectious agent that causes vCJD may develop symptoms at different rates due to their genotype at codon 129. A possible case of vCJD in another M/V patient was reported in 2009 but was not confirmed.
The European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA) view the risk of transmission of vCJD by plasma-derived clotting factor concentrates (CFCs) today as extremely low. No person with haemophilia has ever been diagnosed with vCJD. However, some patients with haemophilia are known to have used CFCs manufactured from plasma of vCJD-infected donors before 1998 and one such patient was found to have signs of vCJD in his spleen although he had no symptoms of the disease.
The Irish Haemophilia Society will continue to monitor the situation.