sequence_alteration [SO_0001059]

sequence_alteration

ID: SO_0001059

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

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.Merged with partially characterized change in nucleotide sequence.