PBREM

PBREM, phenobarbital-responsive enhaneer module Gilbert, Gilbert syndrome CN2, Crigler-Najjar syndrome type II. 

The 60 allele (-3279 T>G) in PBREM is partially linked with the 28 allele namely, the 60 haplotype without the 28 allele is also found (37,38,39) (Fig. 3). Trends of 60 haplotype-dependent decrease in SN-38 G formation (38,47) and increase in total bilirubin levels (38) have been observed in Japanese however, contribution to irinotecan severe toxicides of the 60 allele alone was not clearly demonstrated (41,47,49). 

Figure 5.34 Mechanism of induction of CYP2B6 by a chemical such as the drug phenobarbital. This drug activates a nuclear receptor (CAR).This combines with the retinoid X receptor and binds to PBREM, as specific section of the CYP gene, which stimulates the production of CYP2B6 mRNA leading to the production of CYP2B6 protein and enzyme. Abbreviations CAR, constitutive androstane receptor RXR retinoid X receptor PBREM, phenobarbital-responsive enhancer module.

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