Genetic Prion Disease: Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease / 神经科学通报·英文版

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.

Conhecimento e prática dos enfermeiros sobre hanseníase: ações de controle e eliminação / Conocimiento y práctica de enfermeros acerca de hanseniasis: acciones de control y eliminación / Knowledge and practice of the nurse about leprosy: actions of control and elimination

RESUMO Objetivo: avaliar o conhecimento e a prática de enfermeiros da atenção primária de saúde quanto às ações de controle e eliminação da hanseníase. Método: estudo avaliativo, com abordagem qualitativa, utilizando o Discurso do Sujeito Coletivo, cujos dados foram obtidos por meio de entrevista semiestruturada, realizada com 16 enfermeiros. Resultados: os dados coletados revelaram que os profissionais de saúde possuem conhecimento suficiente sobre a Política Nacional de Controle e Eliminação da Hanseníase (PNCEH) e que as principais ações preconizadas foram executadas, porém, a notificação de casos suspeitos ou confirmados e a reinserção social do doente não foram citadas. Conclusão: manter os doentes em tratamento, sobrecarga de trabalho, falta de interdisciplinaridade e tratamento realizado em outros locais fora da comunidade foram dificuldades relatadas pelos profissionais. Os enfermeiros conhecem as ações direcionadas à assistência ao hanseniano, entretanto, o estudo aponta para a necessidade de uma prática mais alinhada ao que preconiza a PNECH. .

RESUMEN Objetivo: evaluar el conocimiento y la práctica de los enfermeros que trabajan en la atención primaria de salud como las acciones de control y eliminación de la hanseniasis. Método: es un estudio evaluativo con enfoque cualitativo, utilizando el Discurso del Sujeto Colectivo, cuyos datos fueron recolectados a través de entrevistas semi-estructuradas con 16 enfermeros. Resultados: los datos obtenidos revelaron que los profesionales de la salud tienen el conocimiento suficiente sobre la Política Nacional de Control y Erradicación de la Hanseniasis (PNCEH) y que las principales acciones recomendadas se han implementado, pero la notificación de los casos sospechosos o confirmados y reinserción social del paciente no fue mencionado. Conclusión: mantener a los pacientes en tratamiento, exceso de trabajo, falta de interdisciplinariedad y tratamiento realizado en otros lugares fuera de la comunidad fueron problemas reportados por el personal de salud. Los enfermeros conocen las acciones destinadas a ayudar a los pacientes con hanseniasis, sin embargo, el estudio apunta la necesidad de una practica más direccionado a lo que defiende la PNECH. .

ABSTRACT Objective: to assess the knowledge and practice of primary health care nurses about control and elimination actions of leprosy. Method: evaluation study with qualitative approach, using the Discourse of the Collective Subject, data were collected through semi-structured interviews conducted with 16 nurses. Results: the data collected revealed that health professionals have suffi cient knowledge about the National Policy on Control and Elimination of Leprosy (NPCEL) and that the main actions preconized were applied, however, notifi cation of suspected or confi rmed cases and social reintegration of the patient were not mentioned. Conclusion: keeping patients in treatment, overload of work, lack of interdisciplinarity and treatment performed at other locations outside of the community were diffi culties reported by professionals. Nurses know the actions addressed at assistance of leprosy patients, however, the study points to the need for a practice which is more aligned to what advocates NPCEL. .

Prionic diseases / Doencas prionicas

Prion diseases are neurodegenerative illnesses due to the accumulation of small infectious pathogens containing protein but apparently lacking nucleic acid, which have long incubation periods and progress inexorably once clinical symptoms appear. Prions are uniquely resistant to a number of normal decontaminating procedures. The prionopathies [Kuru, Creutzfeldt-Jakob disease (CJD) and its variants, Gerstmann-Sträussler-Scheinker (GSS) syndrome and fatal familial insomnia (FFI)] result from accumulation of abnormal isoforms of the prion protein in the brains of normal animals on both neuronal and non-neuronal cells. The accumulation of this protein or fragments of it in neurons leads to apoptosis and cell death. There is a strong link between mutations in the gene encoding the normal prion protein in humans (PRNP) - located on the short arm of chromosome 20 – and forms of prion disease with a familial predisposition (familial CJD, GSS, FFI). Clinically a prionopathy should be suspected in any case of a fast progressing dementia with ataxia, myoclonus, or in individuals with pathological insomnia associated with dysautonomia. Magnetic resonance imaging, identification of the 14-3-3 protein in the cerebrospinal fluid, tonsil biopsy and genetic studies have been used for in vivo diagnosis circumventing the need of brain biopsy. Histopathology, however, remains the only conclusive method to reach a confident diagnosis. Unfortunately, despite numerous treatment efforts, prionopathies remain short-lasting and fatal diseases.

Doenças priônicas são enfermidades neurodegenerativas devido ao acúmulo de pequenos agentes infecciosos compostos unicamente por proteína (prions), com longos períodos de incubação e de progressão inexorável para o óbito. Esses agentes são excepcionalmente resistentes aos processos habituais de descontaminação para germes e vírus. As prionopatias [Kuru, doença de Creutzfeldt-Jakob (CJD) e suas variantes, Síndrome de Gerstmann-Sträussler-Scheinker (GSS) e insônia familiar fatal (FFI)] resultam do acúmulo de isoformas anormais da proteína priônica no cérebro. Este acúmulo leva, em última análise, à apoptose e morte celular. Existe uma forte associação entre mutações no gene que codifica a proteína priônica normal em humanos (PRNP) - localizado no braço curto do cromossoma 20 - e formas genéticas destas doenças (CJD familiar, GSS, FFI). Clinicamente devemos suspeitar de uma prionopatia em qualquer caso de demência de rápida progressão, particularmente quando associadas a ataxia, mioclonias, ou em indivíduos com insônia patológica combinada com disautonomia. Métodos diagnósticos como ressonância magnética, pesquisa da proteína 14-3-3 no líquido cefalorraquiano, biópsia de amígdalas e estudos genéticos têm sido utilizados para diagnóstico in vivo, evitando-se assim a necessidade de biópsia cerebral. A despeito disso, a histopatologia continua a ser o único método conclusivo para se chegar a um diagnóstico definitivo. Infelizmente, apesar dos inúmeros esforços de tratamento, as prionopatias permanecem doenças de curta duração e fatais.

Discriminant analysis of prion sequences for prediction of susceptibility

Prion diseases, including ovine scrapie, bovine spongiform encephalopathy (BSE), human kuru and Creutzfeldt-Jakob disease (CJD), originate from a conformational change of the normal cellular prion protein (PrPC) into abnormal protease-resistant prion protein (PrPSc). There is concern regarding these prion diseases because of the possibility of their zoonotic infections across species. Mutations and polymorphisms of prion sequences may influence prion-disease susceptibility through the modified expression and conformation of proteins. Rapid determination of susceptibility based on prion-sequence polymorphism information without complex structural and molecular biological analyses may be possible. Information regarding the effects of mutations and polymorphisms on prion-disease susceptibility was collected based on previous studies to classify the susceptibilities of sequences, whereas the BLOSUM62 scoring matrix and the position-specific scoring matrix were utilised to determine the distance of target sequences. The k-nearest neighbour analysis was validated with cross-validation methods. The results indicated that the number of polymorphisms did not influence prion-disease susceptibility, and three and four k-objects showed the best accuracy in identifying the susceptible group. Although sequences with negative polymorphisms showed relatively high accuracy for determination, polymorphisms may still not be an appropriate factor for estimating variation in susceptibility. Discriminant analysis of prion sequences with scoring matrices was attempted as a possible means of determining susceptibility to prion diseases. Further research is required to improve the utility of this method.

Polymorphism of prion protein gene [PRNP] in Iranian holstein and two local cattle populations [Golpayegani and Sistani] of Iran

Bovine spongiform encephalopathy [BSE] is a fatal infectious neurodegenerative disease in cattle, characterized by the accumulation of an abnormal, proteaseresistant prion protein [PrPSc] in the brain. BSE is similar to scrapie in sheep and goats and Creuzfeldt-Jakob disease in humans. Susceptibility in cattle has been shown to be under the influence of two polymorphic locations, which are a 23 bp in/del polymorphism and a 12 bp indel within intron 1 of the prion protein gene [PRNP]. DNA was extracted from blood samples of three Iranian cattle populations including Sistani [Bos indicus] [n=60], Golpayegani [Bos indicus] [n=62] and Iranian Holstein [Bos taurus] [n=50], In order to identify the putative polymorphisms of the PRNP gene of those breeds. Allele, genotype and haplotype frequencies of the polymorphisms were determined for the three populations. Susceptibility analysis was considered as per literature, upon which, it was suggested that the two Bos indicus native populations are more resistant to BSE than the Iranian Holstein [Bos taurus], due to higher gene frequency for insertion allele of the intron 1 of the PRNP gene polymorphism

Genetic variability of the prion protein gene (PRNP) in wild ruminants from Italy and Scotland

The genetics of the prion protein gene (PRNP) play a crucial role in determining the relative susceptibility to transmissible spongiform encephalopathies (TSEs) in several mammalian species. To determine the PRNP gene variability in European red deer (Cervus elaphus), roe deer (Capreolus capreolus) and chamois (Rupicapra rupicapra), the PRNP open reading frame from 715 samples was analysed to reveal a total of ten single nucleotide polymorphisms (SNPs). In red deer, SNPs were found in codons 15, 21, 59, 78, 79, 98, 136, 168 and 226. These polymorphisms give rise to 12 haplotypes, and one of which is identical to the PRNP of American wapiti (Rocky Mountain elk, Cervus elaphus nelsoni). One silent mutation at codon 119 was detected in chamois and no SNPs were found in roe deer. This analysis confirmed that European wild ruminants have a PRNP genetic background that is compatible with TSE susceptibility, including chronic wasting disease.

Nova variante do gene do prionio em uma familia psicotica / New variant of the prion protein gene in a psychotic family

As doencas de prionio sao caracterizadas pelo acumulo no cerebro da PrP-sc, uma proteina prionica infectante e protease resistente. A Prp-sc difere da PrP-c, de funcao desconhecida, apenas em termos conformacionais. As doencas humanas de prionio conhecidas sao Kuru, Gertsman Straussler (GSS), Insonia Familiar Fatal(IFF) e doencas de Creutzfeldt-Jakob (CJD)...

Enfermedades por priones / Prion's disease

La autoreplicación del prion cumple un papel esencial en la patogenia de este grupo de afecciones caracterizadas por la producción de encefalopatías espongiformes, tanto en los casos determinados por un factor genético hereditario como en los provocados por iatrogenia o posiblemente por la ingestión de alimentos o sustancias contaminadas. En ambos casos la producción de una variante conformacional de la proteína prion plantea incógnitas por su mecanismo de replicación sin la intervención de DNA o RNA. Finalmente la implicancia de la epidemia en el ganado bovino aparecida hace más de 10 años en inglaterra, resulta inquietante a la luz de la nueva variante de este origen comunicada en 1996 en los seres humanos.