Comparison of cytochrome P450 (CYP) genes from the mouse and human genomes, including nomenclature recommendations for genes, pseudogenes and alternative-splice variants

The seven CYP clusters are greatly expanded in the mouse with 72 functional genes versus only 27 in the human, while many pseudogenes are present; presumably this phenomenon will be seen in many other gene superfamily clusters. Complete identification of all pseudogene sequences is likely to be clinically important, because some of these highly similar exons can interfere with PCR-based genotyping assays. A naming procedure for each of four categories of CYP pseudogenes is proposed, and we encourage various gene nomenclature committees to consider seriously the adoption and application of this pseudogene nomenclature system.