SCA Tethering-PCR: A Rapid Genetic Test for the Diagnosis of SCA1 –3, 6, and 7 by PCR and Capillary Electrophoresis

Publication date: Available online 17 February 2018 Source:The Journal of Molecular Diagnostics Author(s): Claudia Cagnoli, Alessandro Brussino, Cecilia Mancini, Marina Ferrone, Laura Orsi, Paola Salmin, Patrizia Pappi, Elisa Giorgio, Elisa Pozzi, Simona Cavalieri, Eleonora Di Gregorio, Marta Ferrero, Alessandro Filla, Giuseppe De Michele, Cinzia Gellera, Caterina Mariotti, Suran Nethisinghe, Paola Giunti, Giovanni Stevanin, Alfredo Brusco Spinocerebellar ataxias (SCA) type 1, 2, 3, 6, and 7, associated with a (CAG)n repeat expansion in coding sequences, are the most prevalent autosomal dominant ataxias worldwide (approximately 60% of the cases). In addition, the phenotype of SCA2 expansions has been now extended to Parkinson's disease and amyotrophic lateral sclerosis. Their diagnosis is presently based on a PCR to identify small expanded alleles, followed by a second-level test whenever the suspect of false normal homozygous, or a CAT interruption in SCA1 needs to be verified. Next-generation sequencing still does not allow efficient detection of these repeats. Here, we show the efficacy of a novel, rapid, and cost-effective method to identify and size pathogenic expansions in SCA1–3, 6, and 7 and recognize large alleles or interruptions without a second-level test. Twenty-five healthy controls and 33 expansion carriers were analyzed: alleles migrated consistently in different PCRs/capillary runs, and homozygous subjects were always distinguishable f...
Source: The Journal of Molecular Diagnostics - Category: Pathology Source Type: research