Misidentification of the SARS-CoV-2 Mu variant using commercial mutation screening assays

Izaskun Alejo-Cancho1,2, Ana Gual-de-Torrella3,4, Mikel Gallego5,4

  • 1Microbiology Department, Hospital Universitario Galdakao-Usansolo, Osakidetza Basque Health Service, Galdakao, Spain. i.alejo.cancho@gmail.com.

Archives of Virology
|February 23, 2022
PubMed

Insights

Multiplex real-time RT-PCR can misclassify SARS-CoV-2 variants. Detecting the P681H mutation helps differentiate Mu and Beta strains, improving variant screening accuracy.

Area of Science:

  • Virology
  • Molecular Biology
  • Genetics

Background:

  • Multiplex real-time RT-PCR is a common method for SARS-CoV-2 variant screening.
  • This technique has limitations that can lead to misclassification of viral strains.

Purpose of the Study:

  • To report cases of SARS-CoV-2 Mu variant misclassification as Beta variant.
  • To propose an improved method for distinguishing between Mu and Beta strains.

Main Methods:

  • Analysis of three cases involving misclassification of SARS-CoV-2 Mu variant.
  • Real-time RT-PCR for mutation detection.

Main Results:

  • Three instances where the Mu variant (K417N mutation) was incorrectly identified as the Beta variant.
  • The P681H mutation was identified as a key differentiator between Mu and Beta variants.

Conclusions:

  • The K417N mutation in the Mu strain can lead to its misclassification as the Beta variant using current RT-PCR methods.
  • Detecting the P681H mutation is recommended to accurately distinguish between Mu and Beta SARS-CoV-2 variants.
  • Continuous monitoring of new variants and mutations is crucial for adapting diagnostic workflows.

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