Genetic engineering has emerged as a powerful mechanism for understanding 
biological systems and a potential approach for redressing congenital disease. 
Alongside, the emergence of these technologies in recent decades has risen the 
complementary analysis of the ethical implications of genetic engineering 
techniques and applications. Although viral-mediated approaches have dominated 
initial efforts in gene transfer (GT) methods, an emerging technology involving 
engineered restriction enzymes known as zinc finger nucleases (ZFNs) has become 
a powerful new methodology for gene editing. Given the advantages provided by 
ZFNs for more specific and diverse approaches in gene editing for basic science 
and clinical applications, we discuss how ZFN research can address some of the 
ethical and scientific questions that have been posed for other GT techniques. 
This is of particular importance, given the momentum currently behind ZFNs in 
moving into phase I clinical trials. This study provides a historical account of 
the origins of ZFN technology, an analysis of current techniques and 
applications, and an examination of the ethical issues applicable to 
translational ZFN genetic engineering in early phase clinical trials.