Molecular Basis and Clinical Management of Gaucher Disease

Abstract

Gaucher disease (GD) type I is an autosomal recessive disease caused by a genetic deficiency of lysosomal β-glucocerebrosidase that leads to accumulation of undergraded substrate glucocerebroside and other glycolipids, thus causing damage in different organs. GBA is the only gene in which mutations are known to cause GD. Nearly 300 mutations have been identified in GD patients, including frame-shift mutations, point mutations, deletions, insertions, splice site mutations and recombinants. The variety of phenotypes associated to GD shows imperfect correlation with mutations. GD encompasses a spectrum of clinical findings from a perinatal lethal form to an asymptomatic form. However the classification of GD by clinical subtype is still useful in describing the wide range of clinical findings and broad variability in presentation. Three major clinical types are delineated: type I (chronic nonneuropathic), type II (acute neuropathic), and type III (chronic neuropathic). Patients with type I GD present with visceromegaly, hematological complications, and bone disease. Cardiac and pulmonary complications are rare. Type I GD adult patients have elevated risk of malignancies, Parkinson’s disease or Parkinsonism. Neuropathic forms of GD are rare and clinically ranging from lethal perinatal form to very mild form limited to abnormalities of horizontal ocular saccades. Diagnosis of acid β-glucosylceramidase relies on enzyme activity in peripheral blood leukocytes or skin fibroblasts and/or identification of GBA mutations. Enzyme replacement therapy is an effective treatment for non-neuropathic GD. Substrate inhibitor is the alternative therapy for some patients with GD is miglustat, iminosugar inhibitor of glucocerebroside synthase.