We have recently found that the frequency of OATPC* 15 is significantly higher in patients who experienced myopathy after receiving pravastatin or atorvastatin than in patients without myopathy. However, there were two patients who experienced pravastatininduced myopathy despite the fact that they did not possess OATPC* 15 or other known mutations of OATPC that have been reported to decrease the function of OATPC. In this study, we sequenced all of the exons and exon intron junctions of OATPC of the two patients and found a novel mutation in exon 12 of OATPC in one of the patients. In this mutation (1628TÀG), there is a substitution of Leu to Trp at position 543 in transmembranespanning domain 10 of OATPC. However, the frequency of this mutation in the Japanese population appears to be very low (º1z).