The suggestions given here are based on recommendations for a nomenclature system for human gene mutations presented by the Nomenclature Working Group. For additional information, please consult the following three articles: Antonarakis and the Nomenclature Working Group: Recommendations for a nomenclature system for human gene mutations Hum. Mut. 11: 1-3 (1998); Beaudet et al.: Update on nomenclature for human gene mutations Hum. Mut. 8: 197-202 (1996) and Beutler et al.: Mutation nomenclature: nicknames, systematic names and unique identifiers Hum. Mut. 8: 203-206 (1996).

Consider the following when searching for specific gene mutations:

• Nucleotide changes start with the nucleotide number and the change follows this number. 854A>C denotes that at nucleotide 854 of the reference sequence, A is replaced by a C.
• Deletions are designated by del after the nucleotide number. 6174delT denotes the deletion of T at nucleotide 6174. 6503delTT denotes the deletion of 2 nucleotides at nucleotide 6503.
• Insertions are designated by ins after the nucleotide interval number. 5677insA denotes that A was inserted after nucleotide 5677.
• Intron mutations when the full genomic sequence is not known have been designated by the intron (IVS) number, positive numbers starting from the G of the donor site invariant GT, negative numbers starting from the G of the acceptor site invariant AG. IVS62+1G>A denotes the G to A substitution at nucleotide +1 of intron 62. IVS4-2A>C denotes the A to C substitution at nucleotide -2 of intron 4. When the full length genomic sequence is known, the mutation have been designed by the nucleotide number of the reference sequence.
• For amino acid nomenclature, the format is R1443G (Arginine at codon 1443 substituted by Glycine). The "wild type" amino acid is given before and the mutant amino acid after the codon number. Therefore there is no confusion for the significance of G,C,T and A in the nomenclature. In some cases, however, the mutation is also given as Arg 1443Gly.
• Stop codons are designated by X. For example E1250X (Glutamic acid at codon 1250 substituted by a termination codon).
• In cases where these are available, the Online Mendelian Inheritance in Man (OMIM) unique identifier has been used.