Table 1.

Studies conducted using germline genome editing on human embryos. This table is based on Table 1 included in the article by Niemiec and Howard (2020) published under Creative Common Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

	Year	Authors	Title	Type of modification introduced	Type of embryos used
Clinic	2018	He Jiankui (unpublished, presented at the International Summit on Human Gene Editing, Hong Kong, 2018)	Developing a CCR5-targeted gene editing strategy for embryos using CRISPR/Cas9	Modification of CCR5 gene to increase resistance to HIV infections	Embryos created with sperm of a man who contracted AIDS. Two embryos were implanted to establish a pregnancy which resulted in the live birth of twin girls
Research	2019	Li et al.	Efficient generation of pathogenic A-to-G mutations in human tripronuclear embryos via ABE-mediated base editing	Single nucleotide substitutions in a few genes (base editing)	Tripronuclear embryos created in clinical IVF procedures
	2019	Zhang et al.	Human cleaving embryos enable robust homozygotic nucleotide substitutions by base editors	Single nucleotide substitutions in a few genes (base editing)	Embryos created using immature oocytes from patients undergoing clinical IVF procedures and sperm from donors Tripronuclear embryos obtained in clinical IVF procedures
	2018	Zeng et al.	Correction of the Marfan syndrome pathogenic FBN1 mutation by base editing in human cells and heterozygous embryos	Correction of a mutation in FBN1 gene causing Marfan syndrome by base editing	Embryos created for the purpose of research using immature oocytes from women undergoing IVF procedures
	2017	Zhou et al.	Highly efficient base editing in human tripronuclear zygotes	Single nucleotide substitutions in a few genes (base editing)	Tripronuclear embryos
	2017	Li et al.	Highly efficient and precise base editing in discarded human tripronuclear embryos	Single nucleotide substitutions in a few genes (base editing)	Tripronuclear embryos created in clinical IVF procedures
	2017	Ma et al.	Correction of a pathogenic gene mutation in human embryos	Correction of a mutation that causes hypertrophic cardiomyopathy	Embryos created for the purpose of research (over 100 embryos were created) using oocytes and sperm procured specifically for research
	2017	Tang et al.	CRISPR/Cas9-mediated gene editing in human zygotes using Cas9 protein	Correction of a mutation in HBB gene causing β-thalassemia and a mutation in G6PD gene related to an enzyme deficiency	Embryos created for the purpose of research using immature oocytes and sperm from patients undergoing clinical IVF procedures Tripronuclear embryos created in clinical IVF procedures
	2017	Liang et al.	Correction of β-thalassemia mutant by base editor in human embryos	Correction of a mutation in the HBB gene which causes β-thalassemia (base editing)	Embryos obtained by somatic cell nuclear transfer; immature oocytes were donated by women undergoing IVF procedures
	2017	Fogarty et al.	Genome editing reveals a role for OCT4 in human embryogenesis	Study of the function of the pluripotency transcription factor OCT4 during embryogenesis	Surplus embryos created in clinical IVF procedures
	2016	Kang et al.	Introducing Precise Genetic Modifications into Human 3PN Embryos by CRISPR/Cas-Mediated Genome Editing.	Introduction of an allele of the gene CCR5 associated with a resistance or slower progression of HIV infections	Tripronuclear embryos created in clinical IVF procedures
	2015	Liang et al.	CRISPR/Cas9-Mediated Gene Editing in Human Tripronuclear Zygotes	Modification of HBB gene, which when mutated causes β-thalassemia	Tripronuclear embryos created in clinical IVF procedures