{"id":6361,"date":"2023-02-17T06:48:53","date_gmt":"2023-02-17T06:48:53","guid":{"rendered":"https:\/\/beta.nanion.de\/resource_library\/2019-the-patient-independent-human-ipsc-model-a-new-tool-for-rapid-determination-of-genetic-variant-pathogenicity-in-long-qt-syndrome\/"},"modified":"2023-02-17T06:48:54","modified_gmt":"2023-02-17T06:48:54","slug":"2019-the-patient-independent-human-ipsc-model-a-new-tool-for-rapid-determination-of-genetic-variant-pathogenicity-in-long-qt-syndrome","status":"publish","type":"resource_library","link":"https:\/\/nanion.com\/ja\/resource_library\/2019-the-patient-independent-human-ipsc-model-a-new-tool-for-rapid-determination-of-genetic-variant-pathogenicity-in-long-qt-syndrome\/","title":{"rendered":"2019 &#8211; The patient-independent human iPSC model \u2013 a new tool for rapid determination of genetic variant pathogenicity in long QT syndrome"},"content":{"rendered":"<p>Background Commercial genetic testing for Long QT Syndrome (LQTS) has rapidly expanded, but the inability to accurately predict whether a rare variant is pathogenic has limited its clinical benefit. Novel missense variants are routinely reported as \u201cVariant of Unknown Significance (VUS)\u201d and cannot be used to screen family members at-risk for sudden cardiac death. Better approaches to determine pathogenicity of VUS are needed. Objective To rapidly determine the pathogenicity of a CACNA1C variant reported by commercial genetic testing as a VUS using a patient-independent induced pluripotent stem cell (hiPSC) model. Methods Using CRISPR\/Cas9 genome editing, CACNA1C-p.N639T was introduced into a previously-established hiPSC from an unrelated healthy volunteer, thereby generating a patient-independent hiPSC model. Three independent heterozygous N639T hiPSC lines were generated and differentiated into cardiomyocytes (CM). Electrophysiological properties of N639T hiPSC-CM were compared to those of isogenic and population control hiPSC-CM by measuring the extracellular field potential (EFP) of 96-well hiPSC-CM monolayers, and by patch-clamp. Results Significant EFP prolongation was observed only in optically-stimulated but not in spontaneously-beating N639T hiPSC-CM. Patch clamp studies revealed that N639T prolonged the ventricular action potential by slowing voltage-dependent inactivation of CaV1.2 currents. Heterologous expression studies confirmed the effect of N639T on CaV1.2 inactivation. Conclusion The patient-independent hiPSC model enabled rapid generation of functional data to support reclassification of a CACNA1C VUS to \u201clikely pathogenic\u201d, thereby establishing a novel LQTS type 8 mutation. Furthermore, our results indicate the importance of controlling beating rates to evaluate functional significance of LQTS VUS in high-throughput hiPSC-CM assays.<\/p>\n","protected":false},"featured_media":0,"template":"","products_tags":[34],"resource_type":[75],"application_areas":[50,77],"therapeutic_areas":[54],"target_categories":[61],"target_families":[340],"targets":[91],"resource_keyword":[],"class_list":["post-6361","resource_library","type-resource_library","status-publish","hentry","products_tags-cardioexcyte-96","resource_type-publication","application_areas-ion-channels","application_areas-cell-ipscs-profiling","therapeutic_areas-cardiac-safety-cipa","target_categories-voltage-gated-ion-channels","target_families-cav-channels","targets-cav1-2"],"acf":[],"_links":{"self":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_library\/6361","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_library"}],"about":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/types\/resource_library"}],"wp:attachment":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/media?parent=6361"}],"wp:term":[{"taxonomy":"products_tags","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/products_tags?post=6361"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_type?post=6361"},{"taxonomy":"application_areas","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/application_areas?post=6361"},{"taxonomy":"therapeutic_areas","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/therapeutic_areas?post=6361"},{"taxonomy":"target_categories","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/target_categories?post=6361"},{"taxonomy":"target_families","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/target_families?post=6361"},{"taxonomy":"targets","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/targets?post=6361"},{"taxonomy":"resource_keyword","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_keyword?post=6361"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}