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Japan: Germline / Embryonic

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Lightly Regulated

Germline gene editing is permitted for research, not for reproductive purposes.

Japan’s germline gene editing regulations are looser than in most of the world, but still restricted. Draft guidelines issued in 2018 allow for gene editing of human embryos for research to treat genetic diseases. The guidelines restrict germline gene editing for reproductive purposes and clinical testing but violations are not punishable by law. The guidelines also do not regulate doctors at private hospitals who might use gene editing for treatment; they only regulate researchers.

The Ministry of Education, Culture, Sports, Science and Technology is responsible for regulating germline gene editing. Research requires approval from the ministry and from an ethics panel at the institution or university conducting the research.

After a Chinese scientist altered the DNA of human embryos that were carried to term, many scientists in Japan and around the world argued that germline gene editing should not be used for reproductive purposes, at least until more research is done. Japan’s updated germline gene regulations followed this outcry.

In a world first, in 2018, Kyoto University announced that it would start providing embryonic stem cells to universities and companies for clinical trials. The university uses fertilized eggs left over from fertility treatments. Most countries have been hesitant to produce and distribute embryonic stem cells as their use in research has been highly controversial.

In 2019, the Ministry of Education, Culture, Sports, Science and Technology, reversing an earlier ban, allowed scientists to create animal embryos that contain human cells (aka human-animal chimeras), and subsequently transplant them into surrogate animals. This research may lead to the development of human-compatible organs. The revised guidelines don’t allow fertilization of human-animal chimeras with human eggs or sperm.


  • Human organs in animals: University of Tokyo received approval to grow human organs in rat and mice embryos (aka human-animal chimeras). The research is in its early stages; the goal is to develop human-like pancreases that can be transplanted into humans.

Regulatory Timeline

2019: Japanese science ministry allows scientists to grow human-animal chimeras (human cells in an animal embryo that are transferred to an animal’s uterus), reversing an earlier ban on the practice. The goal is to use animals to grow organs that can be transplanted into humans.

2018: Kyoto University announces it will start providing embryonic stem cells to universities and companies for clinical trials.

 2018: Draft guidelines issued that allow for gene editing research in human embryos. Gene editing embryos for reproductive purposes is not allowed, but is not punishable by law.

2014: Japanese government revises guidelines, making possible the use of human embryonic stem cells in clinical studies as well as laboratory research.

NGO Reaction

Some researchers and bioethicists have raised concerns about Japan’s relaxed guidelines on human-animal chimeras that allow for human cells in animal brains as well as embryos made from both human and primate cells—much more so than if they were only present in heart, blood, or liver tissue. Their concerns echo surveys of the Japanese public that suggest worries that animals could become humanized and that the boundary between humans and animals could become blurred. However, scientists familiar with the research say the chimeras being developed in Japan, if brought to term, would not take on human-like behavior, although the animals might not behave like “normal” rodents.

The International Society for Stem Cell Research (ISSCR) Guidelines for Stem Cell Research and Clinical Translation recommend that animal-human chimera research should not be pursued if it involves breeding part-human chimeras together that have the potential to form human eggs and sperm.

Additional Resources

Click on a country (eg. Brazil, US) or region (eg. European Union) below to find which human / health products and processes are approved or in development and their regulatory status.

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Human / Health Gene Editing Index
Compare Regulatory Restrictions Country-to-Country

Gene editing regulations worldwide are evolving. The Gene Editing Index ratings below represent the current status of gene editing regulations and will be updated as new regulations are passed.

Colors and ratings guide

Regulation StatusRating
Determined: No Unique Regulations*10
Lightly Regulated8
Proposed: No Unique Regulations†6
Ongoing Research, Regulations In Development5
Highly Regulated4
Mostly Prohibited2
Limited Research, No Clear Regulations1
Lightly Regulated: Gene and stem cell therapies regulated with minimal restrictions and requirements.
*Determined: No Unique Regulations: Gene and stem cell therapies regulated as phamaceuticals with no additional restrictions.

†Proposed: No Unique Regulations: Decrees under consideration for gene and stem cell therapies that would not require unique regulations beyond current restrictions on pharmaceuticals.

Gene editing of adult human cells, including gene therapy and stem cell therapy, that is used to treat and cure disease. Recent breakthroughs include CAR T-cell therapy, which uses patients’ own immune cells to treat their cancer.
Gene editing of the human embryo or germline that results in genetic changes that are passed down to the next generation. This type of gene editing is the most controversial because changes are inherited and because it could theoretically be used to create “designer babies”. A Chinese scientist announced in 2018 that he had successfully edited twins that were brought to term. International backlash from the announcement has resulted in China and other countries working to clarify regulations on germline gene editing.

Rating by Country / Region
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Country / RegionTherapeuticGermlineHuman Rating
New Zealand402
Central America111
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Gene editing is a set of techniques that can be used to precisely modify the DNA of almost any organism. It is being used for applications in human health, gene drives and agriculture. There are numerous gene-editing tools besides CRISPR-Cas 9, which gets most of the attention because it is a comparatively easy tool to use.

Gene editing does not usually involve transgenics – moving ‘foreign’ genes between species. It also refers to a specific technique in contrast to the general term GMO, which is scientifically ambiguous, as genetic modification is a process not a product. Most gene editing involves creating new products by deleting very small segments of DNA (sometimes in agriculture called Site-Directed Nuclease 1 or SDN-1 techniques), which can silence a gene or change a gene’s activity. Countries are evaluating whether or not to regulate this type of gene editing, since it is so similar to natural mutations. The GLP’s Gene Editing Index ratings reflect the regulatory status of SDN-1 techniques, which are the most liberally regulated and will generate most products in the near term.

To develop different products, gene editing can change larger segments of DNA or add DNA from other species (a form of transgenics sometimes in agriculture called SDN-2 or SDN-3 techniques). While many countries are not regulating or lightly regulating SDN-1 techniques, most are moving toward tightly regulating or even restricting SDN-2 and SDN-3.

For more background on the various gene editing SDN techniques, read background articles here and here.