Regenerative Medicine Cluster Initiative in BC

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TEDx The Beat Must Go On (Tibbits Laboratory)

Sudden unexpected death of an infant (e.g. SIDS) or young child is a devastating occurrence for a family, particularly when the cause of death cannot be identified despite thorough autopsies, toxicology, microbiology, X-ray or other conventional diagnostic means. The medical community therefore needs to devise new approaches for identifying and managing these a�?autopsy-negativea�? patients.

It has been postulated that ventricular arrhythmias causing sudden cardiac arrest (SCA) are often causal in a�?autopsy-negativea�? sudden infant death syndrome (SIDS).A� The Glen Tibbits Laboratory have recently completed a study sequencing genes from 191 such infants/children, most of whom died in the first year of their lives.A� In this groundbreaking study, they identified 10 children carrying a novel mutation that in a cardiac gene, Troponin I or TNNI1, which is expressed only in the fetus and up to the first year of life and is therefore referred to as the fetal form of the gene.A� In this study, the Tibbits Laboratory used human induced pluripotent stem cells (hiPSCs) to introduce this mutation via the gene-editing technology, CRISPR/Cas9. The mutant hiPSCs were then differentiated into beating cardiomyocytes in culture and plated into monolayers of functional cardiac tissue. The plated monolayers are optically mapped using potentiometric and calcium-sensitive dyes to monitor voltage and calcium transients in real time while the hiPSC-derived cardiomyocytes are beating.The Tibbits Laboratory is now studying the propensity of beating heart cells derived from these mutant hiPSCs to develop potentially fatal heart rhythms and cause sudden cardiac arrest.A� This study has the potential to provide critically needed physiologic and mechanistic bases to implicate this mutation to determine if sudden cardiac death can be the cause of death.A� Because most death investigation agencies in Canada do not use genetic testing to help determine the cause of death in SIDS, these studies have the potential to validate genetic testing as an important tool to identify causes of sudden infant deaths.

To learn more about the Tibbits Laboratory and this study, watch this
TEDx video titledA�a�?The Beat Must Go On”.
By Sanam Shafaattalab (PhD Candidate, Tibbits Lab)
April 2018