An improved procedure for diagnosis of Gaucher disease using cultured skin fibroblasts and the chromogenic substrate, 2-hexadecanoylamino-4-nitrophenyl-β- d-glucopyranoside

A procedure has been developed for the determination of glucocerebrosidase activity using the substrate analogue, 2-N- hexadecanoylamino-4- nitrophenyl-β- d-glucopyranoside (HNGlu) with sodium taurocholate and oleic acid as activators. Cultured skin fibroblasts and amniotic fluid cells have been used as the enzyme source. It has been used successfully to confirm the diagnosis of two Type I and two Type II Gaucher patients. The procedure shows approximately a 15-fold increase in sensitivity over other procedures using HNGlu as substrate. Compared with 4-methylumbelliferyl-β- d-glucoside, HNGlu proves to be a highly specific substrate for glucocerebrosidase with little or no hydrolysis by the other β-glucosidases present in fibroblast extracts. It is therefore the chromogenic substrate of choice for determining a glucocerebrosidase deficiency.