International Journal of Advances in Medicine | September 2021 | Vol 8 | Issue 9 Page 1343 International Journal of Advances in Medicine Garde SS et al. Int J Adv Med. 2021 Sep;8(9):1343-1349 http://www.ijmedicine.com pISSN 2349-3925 | eISSN 2349-3933 Original Research Article Study to establish genetic association of cardiac conduction defect in Indian patients undergoing pacemaker implantation Swapnil S. Garde 1 *, Pranab J. Bhattacharyya 1 , Mohammad Ghaznavi Idris 2 , Romar Dabu 1 , Gautam Hazarika 2 INTRODUCTION The functional components of cardiovascular system can be broadly divided into the impulse-generating nodes and the impulse propagating His-Purkinje system. CCD is a disturbance of impulse conduction that can be permanent or transient depending on the anatomic or functional impairment. 1 Historically, CCD was viewed purely as a structural disease of the heart in which macro or microscopically structural abnormalities in the conduction system underlie disruption of normal impulse propagation. 2,3 In a substantial number of cases, however, conduction disturbances are found to occur in the absence of anatomical abnormalities. Familial background has been demonstrated to determine an individual’s pre- disposition to disease including the development of cardiac arrhythmias. 4,5 Functional CCD is found to be a so- called primary electrical disease of the heart, a group of inherited diseases that result from functionally abnormal or absent, proteins encoded by mutated genes. 6,7 The affected proteins are often cardiac ion channel proteins ABSTRACT Background: The aim was to study the genetic association of cardiac conduction defects (CCDs) by evaluating single nucleotide polymorphism (SNP) in genes of SCN1B and KCNJ2 and to evaluate baseline characteristics between cases and controls. Methods: Case group consisted of 81 individuals with diagnosis of conduction disturbances who underwent permanent pacemaker implantation. The control group consisted of 79 unrelated individuals above 18 years of age of the local population not having a present or past personal or family history (first degree relatives) of any cardiac ailment especially CCDs. Isolation of genomic deoxyribonucleic acid (DNA) from all samples was done, genomic DNA was checked to ensure the presence of intact DNA. Results: SCN1B: SNP rs55742440 had no bearing on the protein except in producing a splice variant. SNP rs67701503 does not lie in the splice-site region, thus not having any significance in the regulation of the gene as well. NetGene2 analysis of SNP rs67486287 negates its presence in the splice site. KCNJ2:SNP rs199473653 leads to a missense amino acid change, resulting in homozygous GG variant found in almost equal frequency in both groups. SNP rs199473653 gene has not been reported as a disease causing mutation. Conclusions: The alteration of nucleotide in SCN1B intron (SNP rs55742440, rs67701503, rs67486287) between cases and controls was found to have no odds of affecting the outcome of CCD. There was no variation or alteration in nucleotide bases of KCNJ2 (SNP rs786205813, rs199473653) between the groups. Keywords: Genetic association, Cardiac conduction defect, Pacemaker implantation 1 Department of Cardiology, 2 Department of Bioengineering and Technology, Gauhati Medical College and Hospital, Guwahati, Assam, India Received: 30 June 2021 Accepted: 23 July 2021 *Correspondence: Dr. Swapnil S. Garde, E-mail: Bqpublication1@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. DOI: https://dx.doi.org/10.18203/2349-3933.ijam20213171