CYP2C9*18 Allele

**Semantic type:** Gene or Genome

**Definition:** Human CYP2C9*18 allele is located within 10q24 and is approximately 33 kb in length. This allele, a variant form of the CYP2C9 wild-type allele, encodes cytochrome P450 2C9*18 protein. The CYP2C9*18 allele exhibits a clinically-relevant SNP (c.1190A>C) in exon 8 that results in a D397A coding change. This alteration in protein sequence decreases the in vivo enzymatic activity of the cytochrome P450 2C9*18 protein.

**Synonyms:** - CYP2C9*18 - CYP2C9, D397A - CYP2C9, c.1190A>C - Cytochrome P450, Family 2, Subfamily C, Polypeptide 9*18 Allele