Recent evidence demonstrating the feasibility of using novel CRISPR/Cas9 gene editing technology to make targeted changes in the DNA of human embryos is forcing researchers, clinicians, and ethicists to revisit the highly controversial issue of altering the inherited human genome.

Currently, developed nations prohibit altering inherited factors, including ones related to disease, because that would open the door for editing to achieve positive traits. The United Kingdom recently allowed "Three-Person IVF" to try and prevent some cases of mitochondrial disease and say they were legally in bounds, though court cases have yet to be decided.

An editorial exploring the current technical limitations, safety concerns, and moral acceptability of therapeutic germline gene editing is published in Human Gene Therapy.

Terence R. Flotte, MD, Incoming Editor-in-Chief (July 2015) of Human Gene Therapy, Celia and Isaac Haidak Professor of Medical Education and Dean, Provost, and Executive Deputy Chancellor, University of Massachusetts Medical School, highlights the safety and efficacy issues associated with the current generation of CRISPR/Cas9 genome editing technology.

In the Editorial "Therapeutic Germline Alteration: Has CRISPR/Cas9 Technology Forced the Question?" Flotte asks, "If and (more likely when) modifications of CRISPR/Cas9 overcome its current limitations, would society find it acceptable to treat a genetic disease in a manner that could be inherited?"

Although the NIH's Recombinant DNA Advisory Committee does not support research involving germline alterations, "it may be necessary to more explicitly clarify guidelines on performing gene editing experiments in non-viable and pre-viable human embryos," proposes Flotte.