A new form of dementia similar to Creutzfeldt-Jakob disease (CJD) has been discovered in the US, New Scientist reports.
The condition has been detected in 16 people, with ten of those individuals having died after gradually losing their mental functions, it says.
It is not known what may have triggered the condition, how many people are affected or how it is transmitted but scientists have identified certain characteristics which make it distinct from CJD.
Pierluigi Gambetti, director of the US National Prion Disease Pathology Surveillance Centre at Case Western Reserve University in Cleveland, Ohio, believes the disease has existed "for many years, unnoticed".
While some very rare forms of CJD have been found to run in families as a result of a gene mutation for a brain protein called PrP, it reports these people have not shown such a mutation.
A woman whose son died from CJD in the UK is running a campaign demanding greater awareness of the condition, Portsmouth's the News website has reported.
It said Christine Lord's campaign site has received millions of hits and she has been contacted by relatives of seven other individuals living within 25 miles of the area who died from CJD.
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