Frequencies of thiopurine S-methyltransferase mutant alleles (TPMT*2, *3A, *3B and *3C) in 151 healthy Japanese subjects and the inheritance of TPMT*3C in the family of a propositus

Authors

  • T. Kubota,

    1. Research Testing Department, SRL, Inc., Hachioji-shi, Tokyo and
    2. Laboratory of Biochemical Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Chiba University, Chiba-shi, Chiba, Japan
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    • Present address: Department of Pharmacy, University of Tokyo Hospital, Faculty of Medicine, Tokyo, Japan.

  • K. Chiba

    1. Laboratory of Biochemical Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Chiba University, Chiba-shi, Chiba, Japan
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Kan Chiba, PhD., Laboratory of Biochemical Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263–8522, Japan. Tel.: /Fax: 81 43 2902919; E-mail: kchiba@p.chiba-u.ac.jp

Abstract

Aims  To determine the frequencies of four thiopurine S-methyltransferase (TPMT) mutant alleles, TPMT*2, *3A, *3B and *3C in a normal Japanese population.

Methods  Genotypes were determined in 151 Japanese subjects and in six family members of a propositus using polymerase chain reaction (PCR)-restriction fragment length polymorphism and allele-specific PCR assays.

Results  Only one TPMT*3C heterozygote was identified (gene frequency 0.3%). TPMT*2,*3A and *3B were not detected. In addition, TPMT*3C was found to have been inherited from the mother and passed on to the son of the propositus.

Conclusions TPMT*3C appears to be most prevalent among the known mutant allele of TPMT in a Japanese population which may have some relevance for the treatment of Japanese patients with thiopurine drugs.

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