CYP1A1 allele nomenclature

CYP1A1 alleles are shown per legacy content of the Human P450 Nomenclature database and have not been updated since 2017. Curation by PharmVar is pending.

Allele	Protein	Nucleotide changes, Gene	Trivial name	Effect	Enzyme activity		References
					In vivo	In vitro
CYP1A1*1	CYP1A1.1	None	Wild-type		Normal	Normal	Jaiswal et al., 1985a Jaiswal et al., 1985b Kawajiri et al., 1986
CYP1A1*2A	CYP1A1.1	3798T>C (MspI)	m1				Bale et al., 1987 Spurr et al., 1987
CYP1A1*2B	CYP1A1.2	2454A>G; 3798T>C (MspI)		I462V			Hayashi et al., 1991
CYP1A1*2C	CYP1A1.2	2454A>G	m2	I462V		Normal	Hayashi et al., 1991 Zhang et al., 1996 Persson et al., 1997
CYP1A1*3	CYP1A1.1	3204T>C	m3				Crofts et al., 1993
CYP1A1*4	CYP1A1.4	2452C>A	m4	T461N			Cascorbi et al., 1996
CYP1A1*5	CYP1A1.5	2460C>A		R464S			Chevalier et al., 2001
CYP1A1*6	CYP1A1.6	1635G>T		M331I			Chevalier et al., 2001
CYP1A1*7		2345_2346insT		426Frameshift			Saito et al., 2003
CYP1A1*8	CYP1A1.8	2413T>A		I448N			Saito et al., 2003
CYP1A1*9	CYP1A1.9	2460C>T		R464C			Saito et al., 2003
CYP1A1*10	CYP1A1.10	2499C>T		R477W			Saito et al., 2003
CYP1A1*11	CYP1A1.11	2545C>G		P492R			Saito et al., 2003
CYP1A1*12	CYP1A1.12	184G>C		A62P			Park et al., 2004
CYP1A1*13	CYP1A1.13	134G>A		G45D			Park et al., 2004
Additional SNPs, where the haplotype has not yet been determined
		-33T>C; 513A>C; 2216C>T; 2958C>T; 3324G>T; 3325G>C; 3422C>A					Solus et al., 2004
		233T>C		I78T			Solus et al., 2004
		18C>G		T173R			Solus et al., 2004
		2515G>A		V482M			Solus et al., 2004
		322G>T		D108Y			Jorge-Nebert et al., 2010
		262G>A		G88S			Jorge-Nebert et al., 2010

Changes made since the last update (08-02-2017) are marked in red.

Allele frequencies: Solus et al., 2004

Links to the NCBI dbSNP homepage are available for functional SNPs when present in NCBI's database.

Nucleotide variations in bold are the major SNPs/alterations responsible for the phenotype of the corresponding allele.

OMIM GeneCards

Note about CYP1A1 nomenclature
Unfortunately two different nomenclature systems were developed for the CYP1A1 alleles simultaneously. The authors of both nomenclature systems have agreed in July 2000 that the nomenclature system given in this homepage should be the recommended one. More information has been published in
Cancer Epidemiology Biomarkers and Prevention.

Below is a table which will facilitate conversion between the two systems:  

Recommended nomenclature on the homepage (see above)	Nomenclature proposed by Garte and Crosti, 1999
CYP1A1*1	CYP1A1*1
CYP1A1*2A	CYP1A1*2
CYP1A1*2C	CYP1A1*3
CYP1A1*3	CYP1A1*4
CYP1A1*4	CYP1A1*5