CYP1A21F

CYP1A21F is not a standard symbol in major human gene nomenclature. It may reflect a misnotation for a CYP1A2 allele (for example CYP1A2*1F) or a variant within the CYP1A gene cluster. Official databases such as HGNC, NCBI Gene, and ClinVar do not list a widely recognized allele designated “CYP1A21F.” When encountered, the designation should be cross-checked against the intended gene symbol and study context.

CYP1A2 is the best known gene in this family; it encodes the hepatic enzyme cytochrome P450 1A2, which participates in the metabolism of caffeine, theophylline, and various prescription drugs. The enzyme is inducible by environmental factors such as smoking and certain dietary compounds, and genetic variation at CYP1A2 can modulate metabolic rate, varying among individuals and populations.

If CYP1A21F were to denote a specific functional variant, its relevance would depend on whether the change is in coding DNA (potentially altering amino acid sequence and enzyme activity) or in a regulatory region (potentially affecting expression levels). Clinically, such variants could influence drug dosing and risk of adverse effects for CYP1A2 substrates, though any claimed association would require replication in peer‑reviewed studies.

See also: CYP1A1, CYP1A2, pharmacogenomics. References: consult official nomenclature databases and primary literature for verified allele designations and functional data.