First report of genetic variants detected in Argentinian patients with clinical Long QT Syndrome diagnosis

Background Long QT Syndrome (LQTS) is a genetic cardiac condition in which disease severity and response to pharmacological treatments vary according to genetic variations. In Argentina, most of the LQTS diagnoses are made by clinical exploration and ECG analysis. In this work, we evaluated a group of subjects from our community to correlate their clinical LQTS diagnosis with genetic modifications. Material and methods : Using gDNA isolation, PCR, and exome sequencing, we screened the coding sequences of the KCNQ1, KCNH2 , and SCN5A genes in the studied cohort. Results We identified several DNA changes, among synonymous and non-synonymous, most of them previously described in the literature. In addition, we found a non reported alteration in the sequence of KCNQ1 sequence that suggests the lack (deletion) of an exon or a large part of it indicating exon deletion. 16 which did not allow us to amplify it. Conclusions This is the first report of genetic variations in LQTS-associated genes in Argentina. The variations detected could explain the prolongation of the QT interval observed in the ECG of some of the individuals or those with a suspicious family history and could improve treatment, making it more rational as well as providing genetic counselling to first-degree relatives. Highlights ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by Ministerio de Educacion VT38-UNS8614 and PGI 24/B269 and PGI 24/B296 ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Hospital Municipal de Agudos Dr. Leonidas Lucero gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors