A sequence_alteration is a sequence_feature whose extent is the deviation from another sequence.

This is just here as a test because I lose it

Term information

IAO alt id

SO:1000004
SO:1000007

IAO id

SO:0001059

IAO subset

SOFA

alternative term

sequence variation

comment

1. A 'sequence alteration' is an allele whose sequence deviates in its entirety from that of other features found at the same genomic location (i.e. it deviates along its entire extent). In this sense, 'sequence alterations' represent the minimal extent an allele can take - i.e. that which is variable with some other feature along its entire sequence). An example is a SNP or insertion. Alleles whose extent goes beyond the specific sequence that is known to be variable are not sequence alterations. These are alleles that represent alternate versions of some larger, named feature. The classic example here is a 'gene allele', which spans the extent of an entire gene, and contains one or more sequence alterations (regions known to vary) as part. 2. Sequence alterations are not necessarily 'variant' in the sense defined in GENO (i.e. being 'variant with' some reference sequence). In any comparison of alleles at a particular location, the choice of a 'reference' is context-dependent - as comparisons in other contexts might consider a different allele to be the reference. So while sequence alterations are usually considered 'variant' in the context in which they are considered, this variant status may not hold at all times. For this reason, the 'sequence alteration' class is not made an rdfs:subClassOf 'variant allele'. For a particular instance of a sequence alteration, howver, we may in some cases be able to rdf:type it as a 'varaint allele' and a 'sequence alteration', in situations where we can be confident that the feature will *never* be considered a reference. For example, experimentally generated mutations in model organism genes that are created expressly to vary from an established reference. 3. Note that we consider novel features gained in a genome to be sequence alterations, including aneusomic chromosomes gained through a non-disjunction event during replication, or extrachromosomal replicons that become part of the heritable genome of a cell or organism.

example of usage

A few examples highlighting the distinction of 'sequence alterations' from their parent 'variant allele': 1. Consider NM_000059.3(BRCA2):c.631G>A variation in the BRCA2 gene. This mutation of a single nucleotide creates a gene allele whose extent is that of the entire BRCA2 gene. This version of the full BRCA2 gene is a 'variant allele', while the extent of sequence spanning just the single altered base is a 'sequence alteration'. See https://www.ncbi.nlm.nih.gov/snp/80358871. 2. Consider the NM_000059.3(BRCA2):c.132_133ins8 variation in the BRCA2 gene. This 8 bp insertion creates a gene allele whose extent is that of the entire BRCA2 gene. This version of the full BRCA2 gene is a 'variant allele', while the extent of sequence spanning just the 8 bp insertion is a 'sequence alteration'. See https://www.ncbi.nlm.nih.gov/snp/483353112. 3. Consider the NM_000059.3(BRCA2):c.22_23delAG variation in the BRCA2 gene. This 2 bp deletion creates a gene allele whose extent is that of the entire BRCA2 gene. This version of the full BRCA2 gene is a 'variant allele', while the junction where the deletion occured is a 'sequence alteration' with an extent of zero. See https://www.ncbi.nlm.nih.gov/snp/483353112.

imported from

http://purl.obolibrary.org/obo/so.owl