Related Experiment Video
Updated: Jul 17, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
A novel duplication type of CYP2A6 gene in African-American population
Tatsuki Fukami1, Miki Nakajima, Hiroyuki Yamanaka
1Drug Metabolism and Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medical Science, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Abstract:
Human CYP2A6 is responsible for the metabolism of nicotine and its genetic polymorphisms affect smoking behavior and risk of lung cancer. In the present study, we identified a novel type of CYP2A6 gene duplication that is created through an unequal crossover event with the CYP2A7 gene at 5.2 to 5.6 kilobases downstream from the stop codon. The novel duplication type of CYP2A6 was found in African Americans (n = 176) at an allele frequency of 1.7%, but was not found in European-American (n = 187), Korean (n = 209), or Japanese (n = 184) populations. The plasma cotinine/nicotine ratio in subjects possessing the novel CYP2A6 gene duplication with the CYP2A6*1 allele (10.8 +/- 7.0, n = 4) was 1.4-fold higher than that in homozygotes of the wild type (8.0 +/- 5.0, n = 87), although the difference was not statistically significant. The findings in the present study suggested that the novel duplicated CYP2A6 allele, which is specific for African Americans, would increase nicotine metabolism and may affect smoking behavior.
More Related Videos
Related Concept Videos
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Principles of Pharmacogenetics: Types of Genetic Variants
Single Nucleotide Polymorphisms-SNPs

