The four most common mutations account for 97% of the Gaucher disease-producing alleles in Jewish patients and 75% of the alleles in non-Jewish patients. Although at least 15 other mutations and some examples of gene conversion and/or fusion genes have been described, a number of mutations remain unidentified. We have now identified six new mutations, a deletion of a C at the 72 position of the cDNA, a 481C-->T mutation (122Pro-->Ser), a 751T-->C (212Tyr-->His), a 1549G-->A (478Gly-->Ser), a 1604G-->A (496Arg-->His), and a 55-bp deletion. All but one of these were found in single families. The 1604A mutation, however, was observed in four unrelated individuals.