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Mutations in Genomic DNA Associated with Sudden Cardiac Death

Mullaney, Tierney
Sudden cardiac death, or SCD, results from the heart failing to pump blood to the rest of the body. Sudden cardiac death, the leading cause of natural death in the United States, and is caused from a variety of factors including diet, lifestyle, and genetics. This research focuses on the underlying genetic cause(s) of heart failure leading to SCD. There are hundreds of genes that can affect cardiac function and to study them all represents an enormous task. Therefore, this study concentrated on a handful of genes suspected to be associated with defects in cardiac function and possibly SCD. The genes studied included: EYA4, TNNI3, MYH6, and NEXN. These genes chosen were based upon the scientific literature and also on some preliminary studies performed in the lab using next generation sequencing on a sample of DNA obtained from a child who died from no known cause and was highly suspected of being an SCD victim. Within these genes, five single nucleotide polymorphisms (SNPs) were identified as candidates for research. SNaPshotTM is a method that allows of several steps that ultimately allow the nucleotide at a particular position within a DNA sequence to be identified. Thus, rather than producing a continuous sequence of nucleotides in a DNA fragment, SNaPshotTM technology allows the nucleotide at one specific position within a DNA fragment to be identified. Using this method, the five SNPs were evaluated to see if the nucleotide in the SNP site was mutated or wildtype. Two groups of individuals (one defined as "normal" or from individuals of older age with no known heart history and the other as "medical examiner samples" or samples from individuals who passed away from a cardiac incident) were tested to determine if there was any correlation between the SNP genotypes and death from pathology associated with the heart.