What does "hfs" or "efs" stand for in amino acid changes?

Question

[kelly.wang135]

Hello,

I am searching for amino acid changes for certain variants.

I don't get the meaning of several results. For example, p.P350Hfs21 and p.K468Efs18

What does Hfs or Efs mean here? I have searched for the HGVS website (https://www.hgvs.org/mutnomen/examplesAA.html), but couldn't get the meaning of it.

Thanks for your help!

Answer 1

[finswimmer]

fs means frameshift.

If you have p.P350Hfs21 this means:

• the coding triplet 350 changes from Prolin to Histidin
• furthermore you have a frameshift (due to deletions/insertions) resulting in a Stop codon 21 codons later

See also here: http://varnomen.hgvs.org/recommendations/protein/variant/frameshift/