RGD Reference Report - Deletion of the entire cytochrome P450 CYP2D6 gene as a cause of impaired drug metabolism in poor metabolizers of the debrisoquine/sparteine polymorphism. - Rat Genome Database

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Deletion of the entire cytochrome P450 CYP2D6 gene as a cause of impaired drug metabolism in poor metabolizers of the debrisoquine/sparteine polymorphism.

Authors: Gaedigk, A  Blum, M  Gaedigk, R  Eichelbaum, M  Meyer, UA 
Citation: Gaedigk A, etal., Am J Hum Genet 1991 May;48(5):943-50.
RGD ID: 1358547
Pubmed: PMID:1673290   (View Abstract at PubMed)
PMCID: PMC1683061   (View Article at PubMed Central)

The debrisoquine/sparteine polymorphism is associated with a clinically important genetic deficiency of oxidative drug metabolism. From 5% to 10% of Caucasians designated as poor metabolizers (PMs) of the debrisoquine/sparteine polymorphism have a severely impaired capacity to metabolize more than 25 therapeutically used drugs. The impaired drug metabolism in PMs is due to the absence of cytochrome P450IID6 protein. The gene controlling the P450IID6 protein, CYP2D6, is located on the long arm of chromosome 22. A pseudogene CYP2D8P and a related gene CYP2D7 are located upstream from CYP2D6. This gene locus is highly polymorphic. After digestion of genomic DNA with XbaI endonuclease, restriction fragments of 11.5 kb and 44 kb represent mutant alleles of the cytochrome CYP2D6 gene locus associated with the PM phenotype. In order to elucidate the molecular mechanism of the mutant allele reflected by the XbaI 11.5-kb fragment, a genomic library was constructed from leukocyte DNA of one individual homozygous for this fragment and screened with the human IID6 cDNA. The CYP2D genes were isolated and characterized by restriction mapping and partial sequencing. We demonstrate that the mutant 11.5-kb allele results from a deletion involving the entire functional CYP2D6 gene. This result provides an explanation for the total absence of P450IID6 protein in the liver of these PMs.

RGD Manual Disease Annotations    Click to see Annotation Detail View
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
Drug-Induced Dyskinesia  ISOCYP2D6 (Homo sapiens)1358547 RGD 

Objects Annotated

Genes (Rattus norvegicus)
Cyp2d4  (cytochrome P450, family 2, subfamily d, polypeptide 4)


Additional Information