Table 1.

Thiopurine S-methyltransferase (TPMT) allele frequencies in Japanese compared with other ethnic populations.

Populatio(n)	*2	*3A	*3C	Reference
Japanese (151)	0	0	0.3	Present study
Chinese (192)	0	0	2.3	Collie-Duguid et al. [9]
British South-west Asian (99)	0	1.0	0	Collie-Duguid et al. [9]
American Caucasian (282)	0.2	3.2	0.2	Hon et al. [8]
British Caucasian (199)	0.5	4.5	0.3	Collie-Duguid et al. [9]
European (191)	0.5	5.7	0.8	De la Moureyre et al. [7]
African Americans (248)	0.4	0.8	2.4	Hon et al. [8]
Ghanaian (217)	0	0	7.6	Ameyaw et al. [10]