Creutzfeldt-Jakob disease associated with an R148H mutation of the prion protein gene

Abstract

Sirs, Prion diseases are transmissible diseases that include sporadic, acquired and familial disorders. More than 30 point mutations and insert mutations of the prion protein gene (PRNP) are thought to cause familial prion diseases, i.e. familial Creutzfeldt-Jakob disease (fCJD), GerstmannStraussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI). Clinical and pathological changes may be similar or indistinguishable from sporadic CJD (sCJD) as in fCJD associated with the E200K mutation, or may be quite different from sCJD as in the P102L mutation that is associated with GSS [1]. The clinical and pathological appearance of sCJD is linked to a methionine–valine polymorphism at codon 129 of PRNP and the biochemical isoform of PrP [2]. The influence of the codon 129 polymorphism in familial prion diseases depends on the particular pathogenic mutation and can be significant. Here we report on a CJD case with an R148H mutation. This patient underwent surgery for hysterectomy when she was 82 years old. After surgery she recovered, but was found somewhat fearful. Five months later she developed a rapidly progressive depressive, anxious disorder, and her state of awareness deteriorated within two weeks. She was admitted to a psychiatric ward. On admission she was disoriented, apprehensive, mistrustful and mute; Babinski’s sign on the right was positive. Within days the patient became somnolent and reacted with a defence reaction to painful stimuli. An evident ‘gegenhalten’ of all extremities was found, and the patient developed myoclonic jerks. She had to be fed by tube. The first EEG showed generalized pathologic alterations, but later periodic sharp wave complexes appeared. In the CT mild cortical atrophy was seen. T2-weighted MRI images revealed symmetric multiple hyperintense lesions in subcortical and periventricular locations. Examinations of the CSF was positive for the 143-3 protein and showed an increased tau protein level (>1,500 pg/ml). The patient was diagnosed with probable sCJD [3]. There was only limited information on her family, but no disease similar to CJD was known in the family. She succumbed six months after the onset of disease and an autopsy was performed. Genomic DNAwas extracted from peripheral blood and was investigated as described [4]. For Western blotting the brain was kept frozen at −80°C until use. Tissue from the frontal cortex and cerebellum was homogenised in 9 volumes (wt./vol) of lysis buffer (0.5% Nonidet P-40, 0.5% DOC, 10 mM EDTA, 100 mM NaCl, 100 mM Tris, pH 7.4) and further processed as described [2]. After PK digestion (50 μg/ml, 1 h at 37°C) cleared homogenates were subjected to SDS-PAGE and blotted on PVDF membranes. Monoclonal antibodies 6H4, 3F4 and L42 were used for immunodetection [5–7]. Blots were developed using NBT-BCIP according to standard protocols. Quantification of band intensities was performed with software TotalLab 1D Gel Analysis, version 2.0. For microscopic investigation the right half of the brain was fixed in formalin and processed for histology, immunohistochemistry and paraffin-embedded tissue (PET) blotting [8]. The monoclonal antibodies L42 and 12F10 were used for immunohistochemistry and PET blotting respectively. B. Krebs . R.-M. Lederer . O. Windl . E.-M. Grasbon-Frodl . H. A. Kretzschmar (*) Institut fur Neuropathologie, LMU Munchen, Feodor-Lynen-Strasse 23, 81377 Munich, Germany e-mail: Hans.Kretzschmar@med.uni-muenchen.de