Comprehensive analysis of UGT1A1 polymorphisms through high-resolution melting analysis and DNA sequencing.

BACKGROUND

Uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) is a key conjugating enzyme of bilirubin and the anti-tumor medication irinotecan. Comprehensive analysis of UGT1A1 gene polymorphisms may provide benefit by predicting pharmacokinetics and outcomes of treatment with irinotecan and certain antiviral medications.

METHODS

A high-resolution melting (HRM) analysis was designed to characterize the UGT1A1 gene. Genomic DNA from 110 healthy subjects was extracted from peripheral blood samples. The promoter and 11 exons from UGT1A1 were screened by HRM, and all results were subsequently confirmed by direct DNA sequencing.

RESULTS

HRM analysis readily identified UGT1A1 gene mutations. We identified 5 different known variants of UGT1A1 including c.211 G > A; G71R, c.686 C > A; P229Q, c.1091 C > T; c.-3279 T > G; and c.-3156 G > A in 110 normal Taiwanese individuals. We also identified 8 new sequence variants, namely, c.-3296 C > T; c.43 C > A; c.45 G > A; c.234 G > A; c.577 G > A; c.614 C > T; c.1011 T > C; and c.1352 C > T. Each UGT1A1 variant was easily identifiable by differences in curves plotted from HRM data.

CONCLUSIONS

HRM analysis was rapid, accurate, and economical for screening UGT1A1 gene mutations.