A second wave of mad cow disease could claim as many as 350 lives in the UK, experts have warned.
The warning comes in the wake of the identification of a patient with variant Creutzfeldt-Jakob disease (vCJD). He seemed to have a genetic make-up different from what has been in previous victims.
All cases of vCJD that have been identified in Britain have so far had the genetic make up MM, found in 42 per cent of the population.
The new case has been found in a person with the make-up MV, carried by 47 per cent of the population.
Variant CJD is part of a group of diseases known as prion disease, which can also appear spontaneously.
Chris Higgins, the Chair of the government's Spongiform Encephalopathy Advisory Committee (SEAC), which advises on variant CJD, told the BBC's Newsnight programme: "The individual has been diagnosed on a clinical basis only and also because of the individual's age it does look more likely to be variant CJD than another form of prion disease."
If the diagnosis is confirmed by a biopsy, the second wave could double the death toll from vCJD, Telegraph reported.
"Given that 160-170 MM individuals were infected we would estimate that the number of MV victims would be a maximum of 300 to 350 (and) probably between 50 and 350."
He added that the patient had been confirmed as an MV genotype.
Last week Hans Kretzschmar, an expert in the disease from the Ludwig-Maximillians University and the Helmholtz Zentrum in Munich, warned in the Lancet Neurology journal that such a case would raise fears that "a second wave of vcjd with a longer incubation time might hit these shores, but we do not know if this will be a tidal wave or just an imperceptible ripple".