They are commonly known by their respective letters, A, C, G and T.
Every one of the directions for building and running the human body are encoded in mixes of those four bases. The scientists corrected a single nucleotide error responsible for β thalassemia, a potentially life-threatening blood disorder, according to a study published last week (September 23) in Protein and Cell.
They scanned DNA for the error then converted a G to an A, correcting the fault.
The experiment was conducted on tissue taken from a patient with the blood disorder and human embryos made through cloning. Unlike CRISPR, the revolutionary genome editor that has received intense attention over the past 5 years, base editing does not require cutting both strands of the DNA to make a fix, theoretically reducing the likelihood of introducing errors.
Prof David Liu, who spearheaded base altering at Harvard University, depicts the approach as "concoction surgery".
He says the technique is more efficient and has fewer unwanted side-effects than Crispr.
He told the BBC: "Around 66% of known human hereditary variations related with disease are point changes".
"More work is needed to assess the precision of this base editing technology (and) to fully investigate both efficiency and specificity of the technique".
The research group at Sun Yat-sen University in Guangzhou hit the headlines before when they were the first to use Crispr on human embryos.
Prof Robin Lovell-Badge, from the Francis Crick Institute in London, described parts of their latest study as "ingenious".
It is inciting profound moral and societal open deliberation about what is and isn't adequate in endeavors to avert disease.
Prof Lovell-Badge said these approaches are unlikely to be used clinically anytime soon.
"There would should be significantly more level headed discussion, covering the morals, and how these methodologies ought to be managed".
"And in many countries, including China, there needs to be more robust mechanisms established for regulation, oversight, and long-term follow-up".