[Gaucher disease: diagnosis and treatment]

Abstract

Gaucher's disease is the most common lysosomal storage disorder. It was identified in 1882 by Phillipe Gaucher, a French dermatologist. However, it was not until 1965 that Gaucher disease was found to be due to a deficiency in the enzyme glucocerebrosidase (EC 3.2.1.45) which breaks down glucocerebroside, a cell membrane component. The deficiency in this enzyme leads to an accumulation of glucocerebroside within the lysosomes of macrophages throughout the body. Gaucher's disease is classified into three types: type 1 (non-neuronopathic), type 2 (acute neuronopathic), and type 3 (subacute neuronopathic). Of the three, type 1 is the most common, affecting one in 40,000-200,000 people and having a high prevalence among Ashkenazi Jews, affecting one in 450-1500. The signs and symptoms of type 1 disease demonstrate marked heterogeneity, from asymptomatic or mildly symptomatic, to severe disability with disfigurement and even death. Hepatosplenomegaly and thrombocytopenia are well documented. Less well-recognized are often insidious skeletal complications which affect the majority of type 1 patients and which are its most debilitating feature. In addition to clinical suspicion, some morphologic, hematologic and biochemical indicators can help establish the diagnosis. However, definitive diagnosis is only made by determining the catalytic activity of the lysosomal enzyme glucocerebrosidase. Confirmation of heterozygosity requires the use of molecular biotechnology methods. About 150 mutations of the glucocerebrosidase gene have been identified in patients with Gaucher's disease, some of which are predictive of phenotype. The history of treatment of Gaucher disease started with splenectomy and continued with bone marrow transplantation, before the recent introduction of safe and effective enzyme replacement therapy. In Croatia, nine patients with type 1 Gaucher's disease have been identified so far. Seven patients are on enzyme replacement therapy, and past results demonstrated significant improvement in all clinical symptoms, without development of any side effects. However, new treatments, such as substrate balance therapy and gene therapy, may become available within the next few years. The place, if any, that such therapies will have in the treatment of patients with Gaucher's disease will be dependent on the results of clinical studies currently in progress.