Long QT Syndrome (LQTS) is a genetically heterogenous arrhythmogenic disorder characterized by prolonged QT interval on the electrocardiogram (ECG). This is associated with an increased risk to develop potentially lethal cardiac events such as syncope, fibrillation, cardiac arrest and even sudden cardiac death (SCD). Up to 17 different genes coding for proteins involved in the regulation of cardiac electrophysiology have been identified to be mutated and define different LQT phenotypes. LQTS type 1 (LQT1) is the most common form and account for near half of LQTS patients worldwide. None of the currently available therapeutic strategies assure an effective cessation of the pathological phenotype, because they do not hit at the genetic basis of the disease. Considering the need of more definite therapies, genome editing could represent a valuable strategy to correct the pathological genetic cause of the disease, and it has been also investigated in other cardiac conditions. Base editing allows to specifically correct single base mutations. In my thesis project, I proposed the development of a base editing system as a tool to correct a single nucleotide LQT1 mutation (c.1781G>A) which was previously characterised. My work focused on the set-up of a base editing methodology able to correct this pathological mutation. I compared the editing efficiency of different base editing systems first using a combination of plasmids containing both the mutation of interest and the editing tools. Then, I used these tools in human induced pluripotent stem cells (hiPSCs) and in hiPSC-derived cardiomyocytes. Our experiments are the proof-of-concept of the feasibility of our base editing approach for the correction of c.1781G>A LQT1 mutation in patient-specific hiPSC-cardiomyocytes.