NR AXUH
AU Peoc'h,K.; Brandel,J.P.; Chasseigneaux,S.; Leandre,S.; Laplanche,J.L.
TI Polymorphism at Codon 129 of PRNP in a Population of Patients Initially Suspected of Creuzfeldt-Jakob Disease
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Pathology and Pathogenesis P03.152
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Human prion diseases are rare neurodegenerative mortal diseases. The most frequent is Creuzfeldt-Jakob disease (CJD) that exists in a sporadic, inherited or acquired form (iatrogenic or variant). A biallelic polymorphism exists at codon 129 of the prion protein gene (PRNP), located in 20pter-p12, coding either a valine or a methionine. In patients with sporadic CJD, homozygous represent about 80% with a predominance of 129 Met/Met, while in controls, they represent 50% in acordance with the Hardy Weinberg equilibrium. Moreover, all patients with clinical variant CJD up to day are 129 Met/Met.
The aim of this study was to determine the repartition of 129 polymorphism in a French population initially suspected of CJD (retrospective study: 1997-2006). The genotype was determined either by PCR-RFLPor DGGE in 1015 patients for which CJD diagnosis was finally discared at posteriori (mean age : 68 y) and in 391 patients with definite sporadic CJD (mean age : 63.8 y).
This is the first study conducted in this type of population. The methionine allelic frequency was estimated at 0.63 in non-CJD patients; heterozygous patients represent 50%, Met/Met patients 40%, Val/val 10%. This distribution is quite similar to that previously observed on a population of blood donors in France [1] or in other European studies[2].
In conclusion, PRNP 129 genotype differs in two population of similar age, patients initially suspected of CJD, and definite sporadic CJD. This study confirms the specificity of surepresentation of homozygous in CJD. Moreover, it confirms that PRNP genotype repartition do not vary with the age class of patients.
1 : Lucotte G, Mercier G. Infect Genet Evol. 2005;5(2):141-4. 2 : Nurmi MH et al ; Acta Neurol Scand. 2003;108(5):374-8.
AD K. Peoc'h, S. Chasseigneaux, S. Léandre, J.L. Laplanche, Hôpital Lariboisière, Service de Biochimie, France; J.P. Brandel, Inserm, U708, France
SP englisch
PO Schottland