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The HGVS Nomenclature is now at https://hgvs-nomenclature.org/.
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a sequence change where, compared to a reference sequence, more than one nucleotide replacing the original sequence are the reverse complement of the original sequence.
Description
Format: “prefix”“positions_inverted”“inv”, e.g. r.123_345inv
“prefix” = reference sequence used = r. “positions_inverted” = range of nucleotides inverted = 123_345 “inv” = type of change is an inversion = inv
Note
all variants should be described at the DNA level, descriptions at the RNA and/or protein level may be given in addition
prefix reference sequences accepted are r. (coding and non-coding RNA)
by definition, the region inverted (“positions_inverted”) contains more then one nucleotide. The description r.234inv is therefore not allowed; a one nucleotide inversion should be described as a substitution
for all descriptions the most 3’ position possible of the reference sequence is arbitrarily assigned to have been changed (3’rule)
inverted duplications are described as an insertion using the format r.234_235ins123_234inv, not as r.123_456dupinv
since exon splice signals will be inverted, large genomic inversions on the RNA level usually give deletion or deletion-insertion (indel) variants
inversions are not used on protein level. Depending on the (predicted) consequences of an inversion on protein level, changes are usually described as either a delins or a frame shift.
Examples
r.177_180inv
inversion of nucleotides r.177 to r.180, changing ..aggcugauu.. to ..aggucaguu..
r.203_506inv
inversion of the 304 nucleotides from position r.203 to r.506
Q&A
Is the change "aagc" to "uucg" an inversion?
No, an inversion would change "aagc" to "gcuu", its revese-complement. "uucg" is only the complement of "aagc".
Is the change "aagc" to "cgaa" an inversion?
No, an inversion would change "aagc" to "gcuu", its revese-complement. CGAA is only the reverse of "aagc".
On the old nomenclature website (bottom) you had the example r.124_500delinsoAB053210.2:r.1289-365_1289-73, i.e. the "o" indicating the inserted sequence AB053210.2:r.1289-365_1289-73 was from the opposite transcriptional strand. Is the "o" still used?
No, the "o" is not used, the insertion is in an inverted orientation so "inv" should be used; r.124_500delinsAB053210.2:r.1289-365_1289-73inv.