How to understand single nucleotide polymorphism (SNP)?

Question

[2001linana]

I was reading an article with title "characterizing sars cov 2 mutations in the united states" lately and got confused about SNP (single nucleotide polymorphism). On page 3 of this article, it mentioned that 4968 mutations are identified in 7823 strains. Then, it talks about "in this work, we extract 7823 single nucleotide polymorphism (SNP) profiles from genome isolates collected in the united states." So, why is it 7823 SNPs ? I thought that, more than likely, it should be 4968. Any comments are greatly appreciated.

Answer 1

[jared.andrews07]

7823 single nucleotide polymorphism (SNP) profiles

So, they found 7823 SNP profiles, as they had 7823 strains. From these profiles, 4968 mutations were found.

[2001linana]

So, these are 7823 SNP profiles, not 7823 SNP's. Is this understanding correct ? So what are the difference between SNP profiles and SNP's then? And what is the meaning of "7823 SNP profiles are decoded from the genome isolates submitted by the US"? Being decoded means being identified?

[jared.andrews07]

Is this understanding correct ?

Yes.

So what are the difference between SNP profiles and SNP's then?

"SNP profile" would correspond to the list of SNPs throughout the genome of a sample rather than a specific SNP.

And what is the meaning of "7823 SNP profiles are decoded from the genome isolates submitted by the US"? Being decoded means being identified?

In this case, yes. I feel decoded is a bit of a confusing word choice there.