Influence of the variable number of tandem repeats located in the promoter region of the thiopurine methyltransferase gene on enzymatic activity

Abstract

Our hypothesis, which emphasizes the number of particular motifs within the VNTR internal structure more than the undiscriminated number of repeats as the potential causative factor affecting TPMT activity, needs further support from future studies, namely, from enlarged population samples. However, the knowledge of the VNTR acting mechanism will represent an important step toward fully understanding how the phenotypic variability at the TPMT trait is modulated.