HGVS

HGVS stands for Human Genome Variation Society, the organization that maintains a set of standardized rules for describing sequence variants, collectively known as the HGVS nomenclature. The system aims to provide precise, unambiguous, and internationally consistent descriptions of genetic variants across DNA, RNA, and protein sequences. It is widely used in clinical genetics, research, and public databases to facilitate communication and data sharing.

Notation in HGVS uses sequence-type prefixes such as g., c., r., n., m., and p. to denote the level of sequence described. Genomic coordinates use g., coding DNA uses c., RNA uses r., protein uses p., and mitochondrial DNA uses m. Reference sequences are specified, often with RefSeq accession numbers, for example NM_000546.5. A variant is described by a position and a base change, e.g., c.76A>G for a single-nucleotide change in coding DNA; g.1091A>G for a genomic change; r.74A>U for an RNA change; p.Arg26Gly for a protein change. Indels and more complex changes use del, ins, and delins, e.g., c.123_125del, c.123_125delinsTT.

Guidance and usage: The HGVS nomenclature is maintained by the HGVS Council and documented on hgvs.org. It emphasizes reporting the most appropriate transcript or reference sequence, using the correct variant type notation, and avoiding obsolete synonyms. The system is widely adopted by clinical laboratories and databases such as ClinVar and Ensembl, and it continues to evolve with updates to reference sequences and genome assemblies.