Authors: Amanda Ramos Mafalda Raposo Montserrat Milà Conceição Bettencourt Henry Houlden Bulmaro Cisneros Jonathan J Magaña Bruno Filipe Bettencourt Jácome BrugesArmas Cristina Santos Manuela Lima
Publish Date: 2015/10/10
Volume: 58, Issue: 1, Pages: 83-87
Abstract
The polyglutamine spinocerebellar ataxias SCAs constitute a clinically and genetically heterogeneous group of rare lateonset neurodegenerative disorders caused by CAG expansions in the coding region of the respective genes Given their considerable clinical overlapping differential diagnosis relies on molecular testing Laboratory best practice guidelines for molecular genetic testing of the SCAs were released in 2010 by the European Molecular Genetics Quality Network following the recognition of gross genotyping errors by some diagnostic laboratories The main goal of this study was to verify the existence of interlaboratorial consistency comparing genotypes for SCA1 SCA2 SCA3 SCA6 and SCA7 obtained by independent diagnostic laboratories The individual impact of different methodological issues on the genotype for the several SCAs was also analysed Four international collaborative diagnostic laboratories provided 79 samples and the respective SCA genotypes Samples were genotyped inhouse for all SCAs using an independent methodology comparison of the allele size obtained with the one provided by the collaborative laboratories was performed Globally no significant differences were identified a result which could be reflecting the fulfilment of recommendations for the molecular testing of SCAs and demonstrating an improvement in genotyping accuracyMR is a recipient of a Fundo Regional para a Ciência PhD scholarship M312/F/006/2011 AR is a Fundo Regional para a Ciência postdoctoral fellow M317/F/031/2011 CB and HH are supported by the UK Medical Research Council MRC This work was partially supported by Generalitat de Catalunya 2014SGR603 PI MM We would like to thank all specialized personnel at the collaborative laboratories that were involved in the molecular diagnosis of the SCA cases hereby studied
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