Introduction

Variant Creutzfeldt–Jakob disease (vCJD) is distinguished from sporadic CJD by a number of characteristics, including a causal association with bovine spongiform encephalopathy (BSE) prions mainly through ingestion, lower sensitivity for 14-3-3 protein in cerebrospinal fluid (CSF), absence of triphasic periodic EEG and death at younger age (mean 28 years vs 65 years).1 Although millions of people have been potentially exposed to the infection, the number of recorded cases of vCJD to date has been small (∼200). One explanation for the low number of cases is that, apart from the homozygosity for methionine at codon 129 of the prion protein gene (PRNP), additional genetic factors might influence the susceptibility to infection.2 3 If there are genetic factors that increase the risk of vCJD, we might expect that the infection would occur in multiple members of certain families with similar exposures. To date, this has not been reported. We describe here a mother and son, in a high-risk BSE region, who developed vCJD.