‘Striking’ coronavirus mutations found within one family cluster, Chinese scientists say
- ‘More work needed’ to determine impact of genetic changes on patients
- Case points to viral evolution in human-to-human transmission, researchers say
While the effects of the mutations on the virus are not known, they do have the potential to alter the way the virus behaves.
Researchers studying a cluster of infections within a family in the southern province of Guangdong said the genes of the virus went through some significant changes as it spread within the family.
Viruses mutate all the time, but most changes are synonymous or “silent”, having little effect on the way the virus behaves. Others, known as nonsynonymous substitutions, can alter biological traits, allowing them to adapt to different environments.
Two nonsynonymous changes took place in the viral strains isolated from the family, according to a new study by Professor Cui Jie and colleagues at the Institut Pasteur of Shanghai.
This case indicated “viral evolution may have occurred during person-to-person transmission”, they wrote in the paper published in the journal National Science Review on January 29.
“Close monitoring of the virus’s mutation, evolution and adaptation is needed,” they added.
Cui’s team also detected a total of 17 nonsynonymous mutations from cases around the country between December 30 and late January, they wrote.
But “we do not have an answer yet” on whether the new coronavirus is changing faster than Sars or other viruses, according to Shi Zhengli, a researcher at the Wuhan Institute of Virology, who was not involved in the study.
Shi said that scientists still did not know the mutation speed of the new coronavirus because “most of the available [viral gene] sequences are not complete. They come in fragments.”
Sequencing entire genomes is time-consuming and expensive. The new coronavirus’ genes also have a total length of nearly 30,000 base pairs, longer than many other viruses, including its distant cousin Sars.
But on Saturday, the Zhejiang Provincial Centre for Disease Control and Prevention (Zhejiang CDC) said it was teaming up with tech giant Alibaba, which owns the South China Morning Post, to develop a new method of genome analysis using artificial intelligence to study the virus from patient samples.
The Zhejiang CDC said the new technology was expected to cut the sequencing time from several hours to about 30 minutes, allowing scientists to track mutations quicker and more precisely.
It is not clear yet what the mutations mean for patients. Qiu Haibo, a member of the national expert panel advising the government on the fight against the virus, said on Sunday that so far there was no evidence that mutations could cause “repeated infections”.
But theoretically, mutations can make recovered patients sick again and cheat existing detection methods because they target only a small segment of the viral genome.
A study led by University of Minnesota researcher Li Fang predicted that a single mutation at a specific spot in the genome could significantly increase the virus’s ability to bind with cells on the surface of the human respiratory system, according to their paper published in the Journal of Virology on January 29.