Gaucher disease is one of the most prevalent lysosomal disorders. In this present study, we report a diagnostic strategy of type 1 Gaucher disease. The application of combined methods in molecular biology allowed us to analyse the p.Asn 370 Ser mutation. The affected individual activity is very low. First, we have to used the enzymatic digestion method. Then, we have to identified the mutation by the refractory mutation system technique using specific primers for the p.Asn 370 Ser mutation. These analyses are supplemented by the direct sequencing in order to seek and confirm this mutation. Finally, the absence of the 55 pb deletion in exon 9 among corroborated the presence of the homozygous genotype of this p.Asn 370 Ser in the patient DNA.