The prevalence of seven different mutations (84GG, IVS2 + 1, 754A, 1226G, 1342C, 1448C, and 1504T) was investigated in 32 unrelated Japanese Gaucher patients of which 20 were type I, 6 were type II, and 6 were type III). These mutations constitute 95% of the mutations observed in Jewish patients with Gaucher disease and 75% of the mutations in non-Jews (European). The most frequent mutation, 1448C (L444P), accounted for 26 alleles (40.6%); the second most prevalent mutation was 754A (F213I), accounting for 7 alleles (10.9%); 27 alleles (42.2%) were unidentified. To data, neither the 1226G (N370S) nor 84GG mutations have been identified in the Japanese population though these alleles account for approximately 70% and 10% of mutations in the Jewish population. These data suggest that mutant alleles identified from the Japanese population are distinct from those observed in Jewish and non-Jewish (European) patients with Gaucher disease.