The National Catholic Bioethics Quarterly

Volume 19, Issue 3, Autumn 2019

Jeanatan Hall
Pages 429-442

The Ethics of Human Tripronuclear Zygotes as Germline Editing Subjects

Despite great interest in the field of gene editing, sparked by the advent of CRISPR/Cas9-mediated applications, the personhood of tripronuclear zygotes has not been addressed appropriately. 3PN zygotes are discarded as medical waste, and their use as models for human genome editing is becoming increasing common. 3PN zygotes possess an extra set of chromosomes, which often leads to severe genetic abnormalities; they are dismissed as “nonviable embryos” and treated as an ethically acceptable alternative to human embryonic research. However, given the development cycle of 3PN zygotes and the qualifications for human personhood assessed, there is compelling evidence that 3PN zygotes are indeed human persons. Although genetically disadvantaged, they deserve the same respect as do genetically normal human zygotes.