IMGT Scientific chart

IMGT description of mutations

Reference to be quoted for IMGT description of mutations:
Lefranc, M.-P. "IMGT Locus on Focus: A new section of Experimental and Clinical Immunogenetics", Exp. Clin. Immunogenet., 15, 1-7 (1998)

IMGT description of mutations

is standardized
follows the IMGT unique numbering for the IG and TR V-REGIONs of all species
starts with the first nucleotide of the first codon for J-REGIONs
applies to both the allele polymorphism mutations and to the somatic hypermutations
applies to every type of mutations: transitions, transversions, deletions, insertions

Nucleotide mutations

Substitutions of nucleotides

Substitutions of nucleotides are designated as g9>c which denotes that the nucleotide 'g' at position 9 is substituted by a 'c', compared to IMGT reference sequence.

Deletions of nucleotides

Deletions of one nucleotide are designated as a95>del#, or if needed a95>del(1nt)#, which denotes that the nucleotide 'a' at position 95 is deleted, compared to IMGT reference sequence. '#' means frameshift.
Deletions of two or more nucleotides are designated as g123-a172>del(50nt)# which denotes that 50 nucleotides (nt), from the nucleotide 'g' at position 123 to the nucleotide 'a' at position 172 included, are deleted, compared to the IMGT reference sequence and according to the IMGT unique numbering. '#' means frameshift.

Insertions of nucleotides

Insertions of nucleotides are designated as 150^151>ins^tatac# which denotes that the nucleotides 'tatac' are inserted at the interval between 150 and 151, compared to IMGT reference sequence. # means frameshift. The carret (^) indicates an insertion.

Amino acid mutations

Substitutions of amino acids

Substitutions of amino acids are designated as R56>S which denotes that the codon 56 for Arginine is substituted by the codon for Serine, compared to IMGT reference sequence.

Deletions of amino acids

Deletions of one amino acid are designated as N32>del or if needed N32>del(1AA), which denotes that the codon 32 for Asparagine is deleted, compared to IMGT reference sequence.
Deletions of two or more amino acids are designated as W41-S57>del(17AA)# which denotes that the codons for 17 amino acids (AA), from codon 41 for Tryptophan to codon 57 for Serine included, are deleted, compared to the IMGT reference sequence and according to the IMGT unique numbering. '#' means frameshift.

Insertions of amino acids

Insertions of amino acids are designated as 50^51>ins^Y# which denotes that the codon for Tyrosine is inserted at the interval between 50 and 51, compared to IMGT reference sequence. '#' means frameshift. The carret (^) indicates an insertion.

'#'	means frameshift.
^	The carret indicates an insertion.
-	The hyphen signifies a range.
*	Stop codons are designated by an asterisk.
	In Tables of alleles, mutations affecting the same codon are described between two vertical lines.
	Examples of complex mutations are described in Somatic hypermutations by insertion or deletion in rearranged cDNA.