Gaucher disease results from mutations in the glucocerebrosidase gene located on human chromosome 1q21. Three clinical forms of Gaucher disease have been described: type 1, nonneuropathic; type 2, acute neuropathic; and type 3, subacute neuropathic. We have identified a novel mutation in a German-British patient with type 1 Gaucher disease which results in V191G of the glucocerebrosidase polypeptide. Because the mutation abolishes a HphI cleavage site, its presence was confirmed by HphI RFLP analysis of PCR-amplified genomic DNA. In the second allele of the patient, the mutation identified was g.5841A G(N370S). Sequence analysis of the remainder of the coding region of the gene as well as the exon-intron boundaries showed identity to normal controls. Because mutation N370S has so far been found only in type 1 Gaucher disease and postulated to result in mild clinical presentation, and since the clinical course of this patient has been relatively mild with minimal skeletal involvement, we speculate that the V191G/N370S genotype may also result in good prognosis.