On the basis of the magnetic resonance imaging findings and the findings of previous case reports of V180I gCJD, we speculate that the characteristic extensive cerebrocortical involvement observed in V180I gCJD was implicated in the pathogenesis of the facial mimicry observed in this case.
The most common hereditary prion disease is a genetic form of Creutzfeldt-Jakob disease in humans, in which a mutation in the prion gene results in a glutamic acid to lysine substitution at position 200 (E200K) in PrP.
These clinicopathological findings led us to several conclusions relative to the early disease pathology of V180I genetic Creutzfeldt-Jakob disease: (i) spongiform change was not found in the medial occipital cortex, which corresponds to the results of DWI; (ii) VaSNoC-type spongiform changes, extensively recognized in the cerebral cortex, corresponded to the DWI findings showing continued hyperintensity with higher brightness, and T2-weighted and FLAIR images findings showing a swelling; and (iii) spongiform changes first appear in the deeper layer and subsequently in the superficial layer in the cerebral cortex.
We believe that pathological laughing and an exaggerated startle reaction are possible pathognomonic findings of V180I genetic Creutzfeldt-Jakob disease.
Notably, mice expressing only PrP V127 were completely resistant to all prion strains, demonstrating a different molecular mechanism to M129V, which provides its relative protection against classical CJD and kuru in the heterozygous state.
Three independent reports have claimed anticipation in Creutzfeldt-Jakob disease (CJD) caused by the c.598G > A mutation in PRNP encoding a p.Glu200Lys (E200K) substitution in the prion protein.
We conclude that the V180I mutation in PRNP produces a late-developing and slow-developing, less severe form of CJD, whose lesions are uniquely distributed compared with sporadic and other genetic forms of CJD.
To this effect, we subjected blood mRNA from E200K PrP CJD patients and corresponding family members to global arrays and found that the expression of Snord3A, a non-coding RNA transcript, was elevated several times in CJD patients as compared to controls, while asymptomatic carriers presented intermediate Snord3A levels.
Three clinical phenotypes were seen: rapidly progressive Creutzfeldt-Jakob disease (CJD), which included 100% of E200K cases, 70% of M232R, and 21% of P102L; slowly progressive CJD, which included 100% of V180I and 30% of M232R; and Gerstmann-Sträussler-Scheinker disease, which included 100% of P105L and 79% of P102L.
Three clinical phenotypes were seen: rapidly progressive Creutzfeldt-Jakob disease (CJD), which included 100% of E200K cases, 70% of M232R, and 21% of P102L; slowly progressive CJD, which included 100% of V180I and 30% of M232R; and Gerstmann-Sträussler-Scheinker disease, which included 100% of P105L and 79% of P102L.
Recently, we reported widespread intraneuronal prion protein (PrP) immunoreactivity in genetic Creutzfeldt-Jakob disease (CJD) associated with the E200K mutation.
From the present observations, the author speculated that pathological laughing and crying may be a comparatively frequent observation in V180ICJD patients.
An important determinant for CJD risk and phenotype is the M129V polymorphism of the human prion protein gene (PRNP), but there are also other coding and non-coding polymorphisms inside this gene.