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People with a DNA mutation that reduces their chance of HIV infection may die sooner, according to a study that suggests tinkering with a gene to try to fix one problem may cause others. The study authors cited the case of the Chinese researcher who tried to produce this mutation in twin girls before their birth, to reduce their risk for HIV.  His work, which produced the first gene-edited babies, was widely condemned as unethical and risky, and the new paper illustrates one reason for concern. (6/3)

The Chinese scientist, He Jiankui, announced last fall that he had created twin girls from an embryo whose DNA he edited in his lab using the powerful gene-editing tool CRISPR. He said he modified a gene known as CCR5 to protect the girls from the AIDS virus. But there's also evidence the CCR5 variation has other effects, such as making people more vulnerable to the West Nile and influenza viruses. "We know it has many different effects. The question is: Is it overall beneficial or detrimental to have this mutation?" Nielsen says. "That was not known." (Stein, 6/3)

A congressional committee is expected to vote on Tuesday to drop a ban on altering the genomes of human embryos intended for pregnancies, which could open the door to creating babies with genetic material from three people or with genomes that have been modified in a way that would be inherited by their descendants, as China’s “CRISPR babies” were. The prohibition on modifying the DNA of embryos for reproduction (as opposed to doing so in basic research that stops short of pregnancies) has been attached to bills that fund the Food and Drug Administration since December 2015. (Begley and Joseph, 6/4)