Community Consultation

Proposal SVD-WG002 (n. prefix)

The proposal suggests to extend the HGVS recommendations by allowing the description of variants based on a non-coding DNA reference sequence indicated by the prefix “n”. In a non-coding DNA reference sequence nucleotide numbering starts with 1 at the first nucleotide of the sequence and ends at the last nucleotide. Intronic nucleotides are numbered as in a coding DNA reference sequence (see Numbering).



The Committee noted concerns related to determining if a particular non-coding sequence is genuinely non-coding, in particular when such sequences do contain an open reading frame. It was felt however that the nomenclature system should match what the reference sequence record purports the sequence type to be. An alternative prefix “nc.” (Non-Coding) was suggested, but it was determined that the precedent of single-letter prefixes for reference sequence (g., c., r., p., m., etc.) should be conserved.

Original proposal