crispr babies
© Reuters / Julia Symmes Cobb
A controversial genetic experiment to make Chinese twins resistant to HIV is causing renewed outrage after the release of the original research, with scientists charging that it failed to meet its goals and ignored basic ethics.

The MIT Technology Review published portions of two previously unseen research papers on Tuesday, principally authored by Chinese biophysicist He Jiankui, who last year attempted to use CRISPR DNA editing technology to immunize twins - Lulu and Nana - against HIV.

While He's bold claims about what the experiment accomplished have come under scrutiny before, a wave of new criticism has followed the publication, which was passed to MIT by an unnamed source. Chief among the complaints is that He's experiment didn't achieve its main goal: producing a mutation in the CCR5 gene that would create resistance to HIV.

The study shows that the research team instead failed to reproduce the prevalent CCR5 variant.

He's claim that "embryo editing will help millions" is also "equal parts delusional and outrageous," Urnov added, comparing it to the idea that the 1969 moonwalk brought "hope" to those looking to live on the moon.

The use of CRISPR to modify DNA in human embryos is largely uncharted territory, and the long term effects on Lulu and Nana remain unclear, with predictions ranging from a reduced lifespan and other health complications to improved cognition and mental enhancement.

Accidental "off-target" mutations also risk unintended effects, which Urnov said could only be detected by destroying an embryo to inspect each cell. Those uncertainties themselves presented ethical challenges for the experiment.

"Unfortunately, [the research] reads more like an experiment in search of a purpose, an attempt to find a defensible reason to use CRISPR technology in human embryos at all costs," said Rita Vassena, scientific director at the Barcelona-based Eugin Group.

Scientists noted other potential ethics issues in He's research, observing that Lulu and Nana's parents belonged to a "vulnerable patient group" due to their father being HIV-positive, which carries an intense stigma in China and might have barred the couple from ever receiving fertility treatment otherwise.

To date, no journal has agreed to publish the research, despite He submitting it to a number of publications since last year, including Nature and the JAMA. Since his work went public, He has kept a low profile, and may even face legal repercussions in China for the contentious experiment.