Mark Scott Kelly NASA twin study

Expedition 45/46 Commander, Astronaut Scott Kelly along with his brother, former Astronaut Mark Kelly / Photographer: Robert Markowitz

Preliminary results from NASA’s twin study suggest that life in space has a big impact on genetics. Astronaut Scott Kelly spent almost an entire year in space while his identical twin brother Mark, also an astronaut, remained earth-bound. Measurements taken before, during, and after Scott’s sojurn in orbit indicate that changes in gene expression, DNA methylation, and other key biological markers may well be due to life in space. 

“Almost everyone is reporting that we see differences”, said Christopher Mason, a geneticist at Weill Cornell Medicine in New York City speaking to Nature. At a meeting of scientists taking part in NASA’s Human Research Program, data fresh off the sequencing machines revealed a vast range of differences, from the lengths of the twins chromosomes, to their gut microbiome composition. Now the challenge is to disentangle the effects of space life from natural variation. 

“Personalized medicine could play into NASA’s plans for how to keep astronauts healthy during long-duration spaceflight, such as any future trips to Mars,” writes Alexandra Witze. 

NASA are already exploring the utility of DNA sequencing for monitoring astronaut health through the Biomolecule Sequencer Project. In August 2016 virologist and astronaut Kate Rubins used the tiny MinION device from UK firm Oxford Nanopore to sequence DNA in space for the first time.

Being able to sequence DNA on the station has potential as a powerful diagnostic tool, for diagnosing mystery ailments in situ, or monitoring the space station environment for potential pathogens. “By sequencing what’s in [astronaut] blood you can find out what they might be suffering from and give them the right treatment,” explained Dan Turner, Senior Director of Applications at Oxford Nanopore, who was involved with the Biomolecule Sequencer project.