Creutzfeldt-Jakob disease in a young person with valine homozygosity at codon 129: sporadic or variant?

To date there have been 52 reported cases of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom. All cases that have undergone genetic investigation have been methionine homozygotes at codon 129 in the prion protein (PrP) gene. There has been speculation as to whether valine homozygosity or heterozygosity at codon 129 confers resistance to vCJD, delays clinical onset of disease,1 or may lead to a clinical syndrome distinct from cases of CJD described so far.2 Here we report on a young patient with CJD who was a valine homozygote at codon 129. A previously well 27 year old electrical engineer complained that he had difficulty concentrating at work. His wife noticed that he had become more forgetful and increasingly agitated which she attributed to stress at work. He was seen in December 1997 and at this stage appeared anxious and with communication difficulties in that he could understand what his wife …