Report on the first Chinese family with Gerstmann-Sträussler-Scheinker disease manifesting the codon 102 mutation in the prion protein gene

Prion protein E219K polymorphism: from the discovery of the KANNO blood group to interventions for human prion disease

KANNO is a new human blood group that was recently discovered. The KANNO antigen shares the PRNP gene with the prion protein and the prion protein E219K polymorphism determines the presence or absence of the KANNO antigen and the development of anti-KANNO alloantibodies. These alloantibodies specifically react with prion proteins, which serve as substrates for conversion into pathological isoforms in some prion diseases and may serve as effective targets for resisting prion infection. These findings establish a potential link between the KANNO blood group and human prion disease via the prion protein E219K polymorphism. We reviewed the interesting correlation between the human PRNP gene's E219K polymorphism and the prion proteins it expresses, as well as human red blood cell antigens. Based on the immune serological principles of human blood cells, the prion protein E219K polymorphism may serve as a foundation for earlier molecular diagnosis and future drug development for prion diseases.

Case report: A Chinese patient with spinocerebellar ataxia finally confirmed as Gerstmann-Sträussler-Scheinker syndrome with P102L mutation

Gerstmann-Sträussler-Scheinker syndrome (GSS) is a rare genetic prion disease caused by a mutation in the prion protein (PRNP) gene. It is typically characterized by progressive cerebellar ataxia and slowly progressive dementia. We present a case study of the GSS from China in which a 45-year-old male with a progressive gait and balance disorder developed cerebellar ataxia onset but was misdiagnosed as spinocerebellar ataxia (SCA) for 2 years. The patient's clinical, electrophysiological, and radiological data were retrospectively analyzed. Examination revealed ataxia, dysarthria, muscle weakness, areflexia in lower limbs, including a pyramidal sign, whereas cognitive decline was insignificant. His late mother had a similar unsteady gait. An electroencephalogram (EEG) showed normal findings, and 14-3-3 protein was negative. A brain MRI was performed for global brain atrophy and ventricular enlargement. Positron emission tomography-computed tomography (PET-CT) (18F-fluoro-2-deoxy-d-glucose, FDG) images showed mild to moderate decreased glucose metabolism in the left superior parietal lobe and left middle temporal lobe. According to genetic testing, his younger brother also had the P102L variant in the PRNP gene. This single case adds to the clinical and genetic phenotypes of GSS.

A family with hereditary cerebellar ataxia finally confirmed as Gerstmann-Straussler-Scheinker syndrome with P102L mutation in PRNP gene

Gerstmann-Sträussler-Scheinker syndrome (GSS) is an exceedingly rare prion disease. There are only 3 case reports of GSS in China. Here we report the first GSS family in southern China. A 47-year-old female complained of unsteady gait and dysarthria. Seven other individuals presented similar symptoms in 3 generations of her family, and all died 4–6 years after onset. To detect causative mutations, we employed a gene analysis panel of hereditary diseases. This revealed a P102L mutation in the prion protein gene (PRNP) gene, which is commonly found in GSS featuring cerebellar ataxia. However, GSS is an uncommon cause of hereditary cerebellar ataxia that might be overlooked because many neurologists are unfamiliar with it. To avoid misdiagnosis in the patients with hereditary cerebellar ataxia, GSS should be taken into account if other causes are absent, especially in patients that have accompanying psychiatric symptoms and a short survival time.

Gerstmann-Sträussler-Scheinker disease: A case report

BACKGROUND

Gerstmann-Sträussler-Scheinker (GSS) disease is an inherited prion disease that is clinically characterized by the early onset of progressive cerebellar ataxia. The incidence of GSS is extremely low and it is particularly rare in China. Therefore, clinicians may easily confuse this disease with other diseases that also cause ataxia, resulting in its under-diagnosis or misdiagnosis.

CASE SUMMARY

Here, we report the first case of genetically diagnosed GSS disease in Northeast China. The patient exhibited typical ataxia and dysarthria 2.5 years after symptom onset. However, magnetic resonance imaging of the brain and spinal cord revealed a normal anatomy. Screening results for the spinocerebellar ataxia gene were also negative. We thus proposed to expand the scope of genetic screening to include over 200 mutations that can cause ataxia. A final diagnosis of GSS was presented and the patient was followed for more than 3.5 years, during which we noted imaging abnormalities. The patient gradually exhibited decorticate posturing and convulsions. We recommended administration of oral sodium valproate, which resolved the convulsions.

CONCLUSION

Patients with inherited ataxia should be considered for a diagnosis of GSS via genetic testing at an early disease stage.

Dominantly inherited prion protein cerebral amyloidoses - a modern view of Gerstmann-Sträussler-Scheinker

Among genetically determined neurodegenerative diseases, the dominantly inherited prion protein cerebral amyloidoses are characterized by deposition of amyloid in cerebral parenchyma or blood vessels. Among them, Gerstmann-Sträussler-Scheinker disease has been the first to be described. Their clinical, neuropathologic, and molecular phenotypes are distinct from those observed in Creutzfeldt-Jakob disease (CJD) and related spongiform encephalopathies. It is not understood why specific mutations in the prion protein gene (PRNP) cause cerebral amyloidosis and others cause CJD. A significant neurobiologic event in these amyloidoses is the frequent coexistence of prion amyloid with tau neurofibrillary pathology, a phenomenon suggesting that similar pathogenetic mechanisms may be shared among different diseases in the sequence of events occurring in the cascade from amyloid formation to tau aggregation. This chapter describes the clinical, neuropathologic, and biochemical phenotypes associated with each of the PRNP mutations causing an inherited cerebral amyloidosis and emphasizes the variability of phenotypes.

Quick and sensitive SPR detection of prion disease-associated isoform (PrPSc) based on its self-assembling behavior on bare gold film and specific interactions with aptamer-graphene oxide (AGO)

Herein, we constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive prion disease-associated isoform (PrP^Sc) detection, utilizing bare gold film and apatamer-graphene oxide (AGO). Due to the self-assembling behavior of PrP^Sc on gold surface, the non-modified gold surface can be directly used as sensing surface for the quick detection, for the purpose to avoid the interference from the traditional, complex and changeable probe-modified sensing surface. And due to the highly specific affinity of AGO towards PrP^Sc, the sandwich type SPR sensor exhibits excellent analytical performance towards the discrimination and quantitation of PrP^Sc. A good linear relationship was obtained between SPR responses and the logarithm of PrP^Sc concentrations over a range of 0.001-1ng/mL. The detection sensitivity for PrP^Sc was improved by ∼156 orders of AGO compared with SPR direct detection format. Besides, morphological changes of the sensing film surfaces were investigated by high resolution AFM imaging, confirming the capture of PrP^Sc molecules and their further specific recognition by AGO. The specificity of the present biosensor was also investigated by PrP^C and other regents as controls. By compared with other reported methods, the AGO enhanced sandwich SPR assay was confirmed to be efficient, sensitive, and with wide working range.

Clinical features of Chinese patients with Gerstmann-Sträussler-Scheinker identified by targeted next-generation sequencing

Gerstmann-Sträussler-Scheinker (GSS) is an autosomal dominant neurodegenerative disease due to mutations within prion protein (PRNP) gene. Clinically, it is not easy to distinguish GSS from spinocerebellar ataxia (SCA), especially in the early stage of disease. We aimed to identify genetic mutations in 8 Chinese pedigrees with dominant ataxia but excluded dynamic mutations of SCA genes. Targeted next-generation sequencing was performed in the 8 probands. A customized panel was designed to capture 24 known causative genes, including 15 autosomal dominant SCA genes and 9 dementia-related genes. A 2-year follow-up was performed in these patients who harbored mutation. Of the 8 probands, 5 were identified to harbor the p.P102L mutation within PRNP. All these 5 cases had progressive ataxia with age at onset ranging from 48 to 52 years (49.5 ± 4.51). Remarkable phenotypic heterogeneity was observed in them. Cognitive decline was found in 4/5 probands. The average duration from initial symptoms to cognitive decline is 32.5 months, ranging from 22 to 48 months. In this study, we presented the detailed clinical features of 5 GSS pedigrees with PRNP p.P102L mutation. The variable phenotypes among these GSS patients indicated other genetic or environmental factors might be involved in the phenotypic heterogeneity of GSS. Our findings also support the proposal that screening of PRNP mutations should be performed for the patients with dominant ataxia if dynamic mutations of SCA genes were excluded.

Gerstmann-Sträussler-Scheinker syndrome with variable phenotype in a new kindred with PRNP-P102L mutation

Gerstmann-Sträussler-Scheinker syndrome (GSS) is a dominantly inherited disorder belonging to the group of transmissible human spongiform encephalopathies or prion diseases. Several families affected by GSS with patients carrying mutations in the prion protein gene have been described worldwide. We report clinical, genealogical, neuropathology and molecular study results from two members of the first Argentine kindred affected by GSS. Both family members presented a frontotemporal-like syndrome, one with and the other without ataxia, with different lesions on neuropathology. A Pro to Leu point mutation at codon 102 (P102L) of the prion protein gene was detected in one of the subjects studied. The pathogenic basis of phenotypic variability observed in this family remains unclear, but resembles that observed in other P102L GSS patients from the same family.

Transmissible spongiform encephalopathies with P102L mutation of PRNP manifesting different phenotypes: clinical, neuroimaging, and electrophysiological studies in Chinese kindred in Taiwan

A P102L point mutation in the prion protein gene (PRNP) usually causes Gerstmann-Sträussler-Scheinker disease (GSS), which is a rare hereditary transmissible spongiform encephalopathy (TSE). The clinical features include ataxia in 50s age group with subsequent dementia, spastic paraparesis and extrapyramidal signs. Many families have been reported from the Caucasian population, but only one from the Chinese. We hereby report a large Chinese family with P102L mutation of PRNP whose clinical manifestations at onset were intriguingly heterogeneous, either rapidly progressive dementia with scanty other neurological features or slowly progressive ataxia followed by cognitive impairment. The four-generation pedigree included eight patients with a mean age at onset of 36.9 +/- 12.9 (mean +/- SD) years. Mean disease duration to death in the four patients was 5.5 +/- 1.7 (mean +/- SD) years. Molecular analysis revealed a P102L mutation and M129 polymorphism in the PRNP gene in all affected individuals. TSE with P102L mutation of PRNP appears to have a remarkably variable phenotypic expressivity that may change with time and does not appear related to the codon 129 polymorphism.