Gaucher disease (GD) is a rare lysosomal storage disorder caused by mutations in the gene encoding acid-Beta-glucosidase (Beta-glucocerebrosidase [GCase]) (Gba), the lysosomal enzyme that catalyzes the breakdown of the lipid glucosylceramide (glucosylcerebroside [GlcCer]). The resulting deficiency in GCase activity leads to an intracellular accumulation of the substrate GlcCer, primarily in macrophage cells. These lipid-laden macrophages, known as Gaucher cells, are the hallmark of the disease and their accumulation in the liver, bone marrow, and spleen elicits the clinical symptoms associated with GD. Pharmacological chaperone therapy is a novel approach to treat diseases due to protein misfolding/mistrafficking using small molecule ligands to rescue and increase the residual function of mutant proteins. For lysosomal storage diseases in which the causative mutant enzymes have residual activity, reversible inhibitors can act as pharmacological chaperones that specifically bind, stabilize, and facilitate the proper folding and trafficking of the mutant enzyme to the lysosome, thereby increasing its ability to degrade the accumulated substrate. AT2101 (isofagomine [IFG] tartrate) is an iminosugar that functions as a selective pharmacological chaperone of GCase that is less stably folded as a result of missense mutations. Current data suggest that AT2101 may work by stabilizing mutant GCase in the endoplasmic reticulum and promoting trafficking of the enzyme to the lysosome. In the lysosome, when the pharmacological chaperone is displaced, the enzyme can perform its normal function, which is the breakdown of glucocerebroside. This study is designed primarily to evaluate and characterize the effects of AT2101 on (GCase) activity and other markers of disease in lymphoblast and macrophage cell lines derived from patients with GD. Fifty subjects with a confirmed diagnosis of GD and a known Gba genotype will be enrolled in the trial. The study will consist of one study visit. Clinical information will be collected retrospectively. Collected information will include but not be limited to GD diagnosis, medical history, family history, assessments of clinical severity and genotype. Blood samples for a series of ex vivo assays will be collected. Blood cell lines will be derived from the subjects' blood samples and used for the ex vivo assays, which will be conducted at a central laboratory.
- INCLUSION CRITERIA: To be eligible for the study, subjects must fulfill all of the following inclusion criteria: 1. Willing and able to provide written informed consent by subject or legal guardian. 2. Male or female of any age. 3. Confirmed diagnosis of GD with known genotype. 4. Clinically stable and either treatment naive or on a stable dose of ERT and/or SRT for at least 6 months prior to study entry. 5. Available medical records for collection of retrospective clinical information. EXCLUSION CRITERIA: To be eligible for the study, subjects must not fulfill any of the following exclusion criteria: 1. Received any investigational product within 30 days prior to study entry. 2. Other significant disease or be otherwise unsuitable for the study, as determined by the investigator.