Community Consultation

Proposal SVD-WG008 (Reference Sequences)

The proposal suggested to specify the HGVS recommendations for acceptable Reference Sequences. Based on the proposal the Reference Sequences page has been updated (April 2020).


A sequence variant is defined in the context of a reference sequence which must be referred to by means of a unique sequence identifier. Because a reference sequence defines the numbering system and default state of a sequence (e.g. coding transcript, non-coding transcript), accurately interpreting a sequence variant requires that both the reference sequence and its reference sequence identifier are unchangeable.



(1) an opaque identifier is one that acts only as a name for an object and that is not intended to be parsed for additional meaning. Contrast with a RefSeq identifier, for example, which conveys annotation level (N versus X), type (M, R, C, etc.), and version number. So, this comment is intended to tell implementers that they may not rely on parsing the identifier to decide how the implementation works

Why not? Two reasons: