A RARE G6490-]A SUBSTITUTION AT THE LAST NUCLEOTIDE OF EXON-10 OF THEGLUCOCEREBROSIDASE GENE IN 2 UNRELATED ITALIAN GAUCHER PATIENTS

Mutation screening of the glucocerebrosidase gene by SSCP analysis rev ealed an abnormal pattern of exon 10 in two unrelated Italian Gaucher patients. Direct sequencing of the mutated samples identified a G6490- ->A transition. The same mutation has been described before in a Japan ese patient with Gaucher disease type III. The clinical phenotype of o ur patients was type I in one whose second allele carried the N370S mu tation and type II in the other one with a L444P mutation. In this lat ter the G6490-->A substitution cancels a normal Msp I site, while on t he opposite chromosome the T6433-->C mutation (L444P) introduces a new Msp I site. Thus, digestion with Map I of the amplified exon 10 is a useful method for identifying the two mutations simultaneously.