Southwestern Internal Medicine Conference: Gaucher disease: A heterogeneous clinical complex for which effective enzyme replacement has come of age

Gaucher disease, the most common form of lysosomal storage disease, is the result of autosomal recessive inheritance of a lysosomal enzyme glucocerebrosidase deficiency, which produces defective hydrolysis of glucosylceramide that accumulates in reticuloendothelial (tissue macrophage) cells. The current review focuses on Type 1 (the nonneuronopathic) or adult Gaucher disease and defines the clinical manifestations (splenomegaly, hepatomegaly, bony lesions, and clinical metabolic dysfunction) in relationship to the known enzymatic defect. The clinical diversity and variability in symptoms and signs, the age at onset of the clinical manifestations and their rate of progression, and the heterogeneity of the organs involved are reviewed. Extensive delineation of the nature of the enzyme defect and the recent molecular characterization of the enzyme mutants has not provided an explanation for the remarkable clinical phenotypic heterogeneity. Enzyme assays now provide an excellent method for diagnosis. Effective enzyme replacement therapy emphasizes the value of early diagnosis and has altered the costs and potential risks of older therapeutic indications for splenectomy or cytokine therapy. Enzyme efficacy raises questions about the specific indications for replacement treatment and the most desirable rate and duration of enzyme delivery.