Molecular genetics of human prion diseases

1994 ◽  
Vol 343 (1306) ◽  
pp. 371-378 ◽  

Human prion diseases occur in inherited, sporadic and acquired forms. The inherited forms are associated with coding mutations in the prion protein gene and the identification of one of these pathogenic mutations allows definitive diagnosis and has resulted in a widening of the previously recognized phenotypic spectrum of these diseases. Study of acquired prion disease provides evidence for genetic susceptibility to development of disease following treatment with contaminated pituitary hormones. Sporadic prion disease occurs predominately in individuals homozygous with respect to a common PrP polymorphism at residue 129. The identification of pathogenic PrP alleles and the role of the codon 129 PrP gene polymorphism in determining susceptibility to prion disease provides strong support for the idea that an abnormal isoform of PrP, PrP Sc , is the principal constituent of the prion and that its propagation involves direct PrP-PrP interactions which occur most readily between identical PrP molecules.

Author(s):  
James A. Mastrianni ◽  
Joshuae G. Gallardo

Prion diseases are transmissible fatal neurodegenerative disorders resulting from the accumulation of misfolded prion protein. Although primarily sporadic diseases, 5% to 10% result from a mutation of the prion protein gene (PRNP), and less than 1% occur from exposure to prions. The current family of prion diseases includes Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), fatal insomnia (FI), variant CJD (vCJD), and variably protease-sensitive prionopathy (VPSPr). Kuru is a disease of historical interest that was transmitted through cannibalistic rituals. Iatrogenic CJD (iCJD) is the result of secondary transmission of prion disease from contaminated biologicals.


Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Hyeon-Ho Kim ◽  
Yong-Chan Kim ◽  
Kiwon Kim ◽  
An-Dang Kim ◽  
Byung-Hoon Jeong

Prion diseases are fatal neurodegenerative disorders characterized by vacuolation and gliosis in the brain. Prion diseases have been reported in several mammals, and genetic polymorphisms of the prion protein gene (PRNP) play an essential role in the vulnerability of prion diseases. However, to date, investigations of PRNP polymorphisms are rare in cats, which are the major host of feline spongiform encephalopathy (FSE). Thus, we investigated the genetic polymorphisms of the cat PRNP gene and analyzed the structural characteristics of the PrP of cats compared to those of dog, prion disease-resistant animal. To investigate the genetic variations of the cat PRNP gene in 208 cats, we performed amplicon sequencing and examined the genotype, allele and haplotype frequencies of cat PRNP polymorphisms. We evaluated the influence of cat PRNP polymorphisms using PolyPhen-2, PANTHER, PROVEAN and AMYCO. In addition, we carried out structural analysis of cat PrP according to the allele of nonsynonymous single nucleotide polymorphism (SNP) (c.457G > A, Glu153Lys) using Swiss-PdbViewer. Finally, we compared the structural differences between cat and canine PrPs for SNPs associated with prion disease resistance in dogs. We identified a total of 15 polymorphisms, including 14 novel SNPs and one insertion/deletion polymorphism (InDel). Among them, Glu153Lys was predicted to affect the structural stability and amyloid propensity of cat PrP. In addition, asparagine at codon 166 of cat PrP was predicted to have longer hydrogen bond than aspartic acid at codon 163 of canine PrP. Furthermore, substitution to dog-specific amino acids in cat PrP showed an increase in structural stability. To the best of our knowledge, this is the first study regarding the structural characteristics of cat PRNP gene.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 193
Author(s):  
Min-Ju Jeong ◽  
Yong-Chan Kim ◽  
Byung-Hoon Jeong

Pathogenic prion protein (PrPSc), converted from normal prion protein (PrPC), causes prion disease. Although prion disease has been reported in several mammalian species, chickens are known to show strong resistance to prion diseases. In addition to chickens, the domestic duck occupies a large proportion in the poultry industry and may be regarded as a potential resistant host against prion disease. However, the DNA sequence of the prion protein gene (PRNP) has not been reported in domestic ducks. Here, we performed amplicon sequencing targeting the duck PRNP gene with the genomic DNA of Pekin ducks. In addition, we aligned the PrP sequence of the Pekin duck with that of various species using ClustalW2 and carried out phylogenetic analysis using Molecular Evolutionary Genetics Analysis X (MEGA X). We also constructed the structural modeling of the tertiary and secondary structures in avian PrP using SWISS-MODEL. Last, we investigated the aggregation propensity on Pekin duck PrP using AMYCO. We first reported the DNA sequence of the PRNP gene in Pekin ducks and found that the PrP sequence of Pekin ducks is more similar to that of geese than to that of chickens and mallards (wild ducks). Interestingly, Pekin duck PrP showed a high proportion of β-sheets compared to that of chicken PrP, and a high aggregation propensity compared to that of avian PrPs. However, Pekin duck PrP with substitutions of chicken-specific amino acids showed reduced aggregation propensities. To the best of our knowledge, this is the first report on the genetic characteristics of the PRNP sequence in Pekin ducks.


Author(s):  
Patrick JM Urwin ◽  
Anna M Molesworth

Human prion diseases comprise a number of rare and fatal neurodegenerative conditions that result from the accumulation in the central nervous system of an abnormal form of a naturally occurring protein, called the prion protein. The diseases occur in genetic, sporadic, and acquired forms: genetic disease is associated with mutations in the prion protein gene (PRNP); sporadic disease is thought to result from a spontaneous protein misfolding event; acquired disease results from transmission of infection from an animal or another human. The potential transmissibility of the prion in any of these forms, either in disease states or during the incubation period, has implications for public health. Here we focus on Creutzfeldt-Jakob Disease (CJD), including variant Creutzfeldt-Jakob Disease (vCJD), although we will also discuss other forms of human prion disease.


Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1480 ◽  
Author(s):  
Yong-Chan Kim ◽  
Sae-Young Won ◽  
Byung-Hoon Jeong

Prion diseases are caused by misfolded prion protein (PrPSc) and are accompanied by spongiform vacuolation of brain lesions. Approximately three centuries have passed since prion diseases were first discovered around the world; however, the exact role of certain factors affecting the causative agent of prion diseases is still debatable. In recent studies, somatic mutations were assumed to be cause of several diseases. Thus, we postulated that genetically unstable cancer tissue may cause somatic mutations in the prion protein gene (PRNP), which could trigger the onset of prion diseases. To identify somatic mutations in the PRNP gene in cancer tissues, we analyzed somatic mutations in the PRNP gene in cancer patients using the Cancer Genome Atlas (TCGA) database. In addition, to evaluate whether the somatic mutations in the PRNP gene in cancer patients had a damaging effect, we performed in silico analysis using PolyPhen-2, PANTHER, PROVEAN, and AMYCO. We identified a total of 48 somatic mutations in the PRNP gene, including 8 somatic mutations that are known pathogenic mutations of prion diseases. We identified significantly different distributions among the types of cancer, the mutation counts, and the ages of diagnosis between the total cancer patient population and cancer patients carrying somatic mutations in the PRNP gene. Strikingly, although invasive breast carcinoma and glioblastoma accounted for a high percentage of the total cancer patient population (9.9% and 5.4%, respectively), somatic mutations in the PRNP gene have not been identified in these two cancer types. We suggested the possibility that somatic mutations of the PRNP gene in glioblastoma can be masked by a diagnosis of prion disease. In addition, we found four aggregation-prone somatic mutations, these being L125F, E146Q, R151C, and K204N. To the best of our knowledge, this is the first specific analysis of the somatic mutations in the PRNP gene in cancer patients.


2019 ◽  
Vol 78 (11) ◽  
pp. 980-992 ◽  
Author(s):  
Aušrinė Areškevičiūtė ◽  
Helle Broholm ◽  
Linea C Melchior ◽  
Anna Bartoletti-Stella ◽  
Piero Parchi ◽  
...  

Abstract The purpose of this study was to perform an updated reclassification of all definite prion disease cases with available fresh-frozen samples referred to the Danish Reference Center over the past 40 years, putting a special emphasis on the molecular characterization of novel disease subtypes. Investigation of the Danish prion diseases cohort revealed rare sporadic Creutzfeldt-Jakob disease cases with mixed subtypes and subtypes with previously uncharacterized white matter plaques, a new case of sporadic fatal insomnia, and 3 novel mutations, including 2 large octapeptide repeat insertions, and a point mutation in the prion protein gene. The evaluation of methionine and valine distribution at codon 129 among the prion disease patients in the cohort revealed the increased prevalence of methionine homozygotes compared to the general population. This observation was in line with the prevalence reported in other Caucasian prion disease cohort studies. Reclassification of the old prion diseases cohort revealed unique cases, the molecular characterization of which improves prion diseases classification, diagnostic accuracy, genetic counseling of affected families, and the understanding of disease biology.


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