To measure the realization of the right to science with regard to research with gametes and embryos, we looked at whether the following are prohibited, restricted or permitted: basic research with gametes and embryos; pre-clinical research using germline modification technologies in animals; clinical research using germline modification technologies; and clinical applications of research using germline modification technologies.
Very few countries permit the creation of embryos for research purposes. When legal systems do not prohibit research with embryos, only embryos that are no longer used in assisted reproduction (supernumerary embryos) can be used. The problem is that, by the time they reach the lab, these embryos have already undergone substantial development. As a result, they are not ideal candidates for research using genome editing techniques. The ideal situation for scientists is to be able to experiment on gametes and pre-embryos. Currently, this is arguably possible only in a handful of countries (Belgium, China, Singapore, Spain, Singapore, Sweden, the United Kingdom, and the United States).
Pre-clinical trials are permitted in a majority of countries. Clinical trials on humans, although currently premature because of the lack of sufficient knowledge coming from basic and pre-clinical research, are prohibited in several countries. This raises a red flag because, when sufficient knowledge will be accumulated, clinical trials are needed to enable the transfer of benefits to patients.
An important footnote to our research is that laws and regulations are often ambiguous about the legality of certain practices. Legal uncertainty works to the detriment of scientists, who may be hesitant to invest professional and personal energies in research that is not expressly lawful.