Objective: To report two members of the same family carrying the valine to isoleucine point mutation of the prion protein gene (PRNP) and presenting with visual symptoms as initial manifestation as in the "Heidenhain variant" of sporadic Creutzfeldt-Jakob disease (CJD).
Methods: Patients underwent neurological examination, electroencephalogram (EEG), brain magnetic resonance images (MRI) and cerebrospinal fluid (CSF) analysis including the Real Time Quaking Induced Conversion (RT-QuIC) test. Disease-specific mutations and polymorphism at codon 129 of the PRNP gene were also studied.
Results: Isolated visual symptoms characterized disease onset of both patients followed by progressive neurological signs, dementia and death in 3 (proband) and 9 (his aunt) months. RT-QuIC analysis of CSF samples of both patients revealed the presence of the pathological prion protein and DNA analysis the V210I point mutation of the PRNP and methionine homozygosity at the polymorphic codon 129.
Conclusions: This report suggests to consider the diagnosis of V210I genetic CJD in patients presenting with the Heidenhain form of CJD and highlights the importance of genetic testing in all patients with isolated visual manifestations at onset followed by progressive neurological signs and dementia.
Keywords: Creutzfeldt–Jakob disease; Heidenhain variant; PRNP gene; RT-QuIC; mutation.