A single test utilizing a unified multiplex PCR/CE workflow targeting five dominant inherited ataxias

Summary Our goal is to develop and commercialize a multiplexed assay for dominant hereditary ataxias to rapidly and accurately analyze short tandem repeatSTRlengths leading to a positive impact on DNA based diagnostics screeningAtaxia is the loss of full control of body movements and indicates a dysfunction of the nervous system and have a range of causes including hereditary and acquiredSpinocerebellar ataxiaSCAis a raredominantly inherited disease family with overknown typesThe most common SCAsandare caused by STR expansions in ATXNATXNATXNCACNA aand ATXNrespectively and responsible for andgtcases worldwideIn the USthere are an estimatedpeople affected with hereditary ataxiaDue to the overlapping nature of disease presentationsymptomsand age of onset between different ataxiasmolecular profiling is key to diagnosishowever undiagnosed and misdiagnosed estimates are between one third and one fifth of the potential patients due incomplete or inaccurate testingHigh quality allele sizing is critical for accurate diagnosisNext generation sequencing panels are available although unsuitable for STR expansions due to limitations in read size and sequence complexityOther methodsincluding single assay PCR followed by Southern blotare cumbersomecostlyand difficult to size accuratelyOur approach utilizes PCR AmplideX chemistry combined with capillary electrophoresisCEto provide a fastaccurate and cost effective multiplex test compared to currently available assaysWe believe a unified testing paradigm will advance clinical researchmolecular diagnostics and drug development for the most prevalent dominant ataxiasTo support a rapid adoption of the kita single tube multiplex PCR test will be developedCE instruments are efficientpracticaland are broadly used in most molecular diagnostics laboratoriesTo improve robust early assay designthe Oxford NanoporeNPrd generation sequencing platform will be used as a reference assay for determining concordance as an independent orthogonal methodAimEnable the detection of each of the disease causing expanded repeat regions of ATXNATXNATXNCACNA aand ATXNindividually using AmplideX PCR CE chemistryAimDevelop a unified multiplex PCR based assay to determine STR sizing for ATXNATXNATXNCACNA aand ATXNin a single tube onclinical isolatesOur approach will provide a fastaccurate and cost effective multiplex test compared to available assaysadvancing clinical researchmolecular diagnostics and drug development for dominant ataxiasOur approach will result in an on market PCR CE RUO kit within two years after funding support Narrative Our proposed assay is a single test that will be able to determine the presence of disease causing mutations in five separate diseasesSCASCASCASCAand SCAThese diseases are dominantly inherited ataxias and are genetically distinct from each otherhoweverthey present with very similar symptoms and have a similar disease progressionThese five diseases together account for andgtof all diagnosed dominant ataxias worldwide and are at risk of under diagnosis due to the inherent difficulty in determining the presence of a disease causing mutation