Is the world ready for human germline genetic editing using CRISPR/Cas9?

Abstract

The use of gene editing (GE) technologies like CRISPR/Cas9 on human embryos constitutes a controversial application that would primarily rely on in vitro fertilization (IVF) and preimplantation genetic testing (PGT) technologies to be applicable clinically. In today's world, IVF is rapidly advancing through artificial intelligence, time-lapse microscopic cinematography, and microfluidics, thereby edging closer to this ethically complex application. PGT results, on the other hand, could possibly be unrepresentative of embryo genomes due to the normalized testing of extraembryonic cell lineages (that form the placenta), instead of testing embryonic cell lineages (that form the embryo): a critical error that is based on outdated science. While the use of CRISPR/Cas9 on human embryos has varied results in different studies, some approaches to the gene-editing tool could prove more effective on embryos than others. The discussion of to what extent this tool should be used has received significant attention in the scientific community. Although, a lack of global consensus gives no clear answer to this essential question for research to continue in this field. This paper will discuss IVF and PGT in the context of human germline gene editing using CRISPR/Cas9, as well as the gene-editing tool's applications, limitations, and ethical considerations on human embryos.