A map depicting variations in countries’ regulations on CRISPR-edited human embryos in 2014 showed Mexico as having banned the practice for reproductive purposes (see Nature 526, 310–311; 2015). In fact, the law was ambiguous, and it still is.

Human genetic engineering and human genome editing are not explicitly regulated in Mexico. The birth in 2016 of the first ‘three-parent’ baby, produced in Mexico by maternal spindle transfer for mitochondrial-replacement therapy (see Nature http://doi.org/btr9; 2016), raised ethical concerns, amid allegations that the procedures were not properly supervised (see C. Palacios-González and M. J. Medina-Arellano J. Law Biosci. 4, 50–69; 2017).

These concerns and the birth of the world’s first gene-edited babies in China last year are prompting calls from the Office of Scientific and Technological Information for the Congress of the Union to reform Mexico’s General Health Law, which gives every citizen the right to health protection. All clinical applications of CRISPR technology should be regulated and supervised, with penalties for procedures that are not safety-tested in humans first.

Until then, a research committee at my institution will set guidelines based on the international regulation of CRISPR applications for clinical protocols.