Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002986 (Fabry)
 5,646 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A point mutation in exon 6 of the alpha-galactosidase A gene (alpha-GAL A) was found in a Japanese hemizygous male without typical manifestations of Fabry disease other than renal involvement. This 45-year-old man developed moderate proteinuria and was diagnosed with Fabry disease on the basis of renal histologic findings and prominent decreases in alpha-GAL A activity in his plasma, urine, leukocytes, and skin fibroblasts. Determination of the cDNA sequence of his alpha-GAL A gene revealed substitution of a G to A in codon 301, resulting in a glutamine rather than an arginine residue. Our case is unique in that this patient only demonstrated renal manifestations while all other reported patients with atypical Fabry disease, including a case with the identical point mutation, present with a cardiomyopathy. Direct DNA sequencing of exon 6 and measurement of alpha-GAL A activity among the patient's family confirmed that the mutation was transmitted from his mother.
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PMID:Point mutation in the alpha-galactosidase A gene of atypical Fabry disease with only nephropathy. 873 59

In the lysosome, glycosidases degrade glycolipids, glycoproteins, and oligosaccharides. Mutations in glycosidases cause disorders characterized by the deposition of undegraded carbohydrates. Schindler and Fabry diseases are caused by the incomplete degradation of carbohydrates with terminal alpha-N-acetylgalactosamine and alpha-galactose, respectively. Here we present the X-ray structure of alpha-N-acetylgalactosaminidase (alpha-NAGAL), the glycosidase that removes alpha-N-acetylgalactosamine, and the structure with bound ligand. The active site residues of alpha-NAGAL are conserved in the closely related enzyme a-galactosidase A (alpha-GAL). The structure demonstrates the catalytic mechanisms of both enzymes and reveals the structural basis of mutations causing Schindler and Fabry diseases. As alpha-NAGAL and alpha-GAL produce type O "universal donor" blood from type A and type B blood, the alpha-NAGAL structure will aid in the engineering of improved enzymes for blood conversion.
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PMID:The 1.9 A structure of alpha-N-acetylgalactosaminidase: molecular basis of glycosidase deficiency diseases. 1200 40

Fabry disease is a lysosomal storage disease caused by deficiency in the enzyme alpha-galactosidase (alpha-GAL). To understand the molecular defects responsible for Fabry disease, we have collected more than 190 reported point and stop mutations and mapped them onto a model of human alpha-GAL based on the X-ray structure of the closely related enzyme alpha-N-acetylgalactosaminidase (alpha-NAGAL). The locations of the human alpha-GAL point mutations reveal two major classes of Fabry disease protein defects: active site mutations and folding mutations. Active site mutations reduce enzymatic activity by perturbing the active site without necessarily affecting the overall alpha-GAL structure. Folding mutations reduce the stability of alpha-GAL by disrupting its hydrophobic core. Examining the frequency of mutation around each alpha-GAL residue identifies the active site as a hotspot for mutations leading to Fabry disease. This study furthers our understanding of the structural basis for mutations leading to Fabry disease, from which new avenues for the treatment of lysosomal storage diseases may be developed.
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PMID:Structural basis of Fabry disease. 1235 24

Aim of this study was to confirm the initial results of a clinical trial on the treatment of Fabry's disease carried out in 13 Italian Nephrology Units. Fabry's disease is a rare, X-linked inherited disease, characterized by a-galactosidase (a-GAL) deficiency, a lysosomial enzymatic activity that results in the accumulation of neutral glycosphingolipids in the endothelial cells of the whole body, and causes painful crises, acroparesthesiae, angiokeratomas, corneal and lens dystrophy, and progressive damage to kidneys, heart and central nervous system, as well as potentially leading to death. The present availability of the recombinant form of a-GAL allows us to prevent or stop the long-term complications of this disease. A clinical trial, generously supported by Genzyme, was started on February 2001. In this trial 20 patients affected by Fabry's disease were periodically treated with agalsidase-beta, the commercial form of the enzyme. The initial results of the trial have indicated that the drug is capable of reducing both the number and intensity of painful crises, improving the patient's sensation of well-being, thus suggesting that this therapeutic approach might theoretically increase life expectancy in these patients.
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PMID:[Anderson-Fabry's disease: diagnostic problems, therapeutic relevance, and clinical experience in the treatment of the disease with enzyme replacement therapy in nephropathic patients]. 1274 95

Fabry disease is an X-linked lysosomal storage disease afflicting 1 in 40,000 males with chronic pain, vascular degeneration, cardiac impairment, and other symptoms. Deficiency in the lysosomal enzyme alpha-galactosidase (alpha-GAL) causes an accumulation of its substrate, which ultimately leads to Fabry disease symptoms. Here, we present the structure of the human alpha-GAL glycoprotein determined by X-ray crystallography. The structure is a homodimer with each monomer containing a (beta/alpha)8 domain with the active site and an antiparallel beta domain. N-linked carbohydrate appears at six sites in the glycoprotein dimer, revealing the basis for lysosomal transport via the mannose-6-phosphate receptor. To understand how the enzyme cleaves galactose from glycoproteins and glycolipids, we also determined the structure of the complex of alpha-GAL with its catalytic product. The catalytic mechanism of the enzyme is revealed by the location of two aspartic acid residues (D170 and D231), which act as a nucleophile and an acid/base, respectively. As a point mutation in alpha-GAL can lead to Fabry disease, we have catalogued and plotted the locations of 245 missense and nonsense mutations in the three-dimensional structure. The structure of human alpha-GAL brings Fabry disease into the realm of molecular diseases, where insights into the structural basis of the disease phenotypes might help guide the clinical treatment of patients.
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PMID:The molecular defect leading to Fabry disease: structure of human alpha-galactosidase. 1500 50

Fabry disease is a rare, progressive lysosomal storage disorder caused by mutation in the GAL gene and an impaired function of the alpha-galactosidase A enzyme. The enzymatic defect results in the progressive accumulation of glycosphingolipids in endothelial cells, smooth muscle cells, leucocytes and fibroblasts leading to organ damage in the skin, eye, nervous system, kidney and heart. Major clinical manifestations include acroparesthesis, angiokeratoma, corneal opacities, vascular diseases of the heart, kidney, and the central nervous system. Enzyme replacement therapy has recently become available for the treatment of Fabry patients. In this review the authors describe clinical features of Fabry disease in 31 Hungarian patients. At the time of this analysis the database consisted of 31 cases (15 males, 16 females) of whom 5 have died (4 males, 1 female). The most common disease-specific manifestation was angiokeratoma in males, and eye symptoms in females. 25% of female subjects were symptom free. Genotyping was performed in all cases and disease-causing mutations were found in all families. Three new mutations were identified. Twelve patients (8 males and 4 females) are currently receiving enzyme replacement therapy.
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PMID:[Molecular pathology and clinical manifestations of Fabry disease]. 1754 17

Fabry's disease, a disorder affecting the gene for the lysosomal enzyme alpha-galactosidase A (alpha-GAL A), can cause accumulation of globotriaosylceramide (GL-3) in the vascular endothelial cells. Symptoms include pain, angiokeratoma, corneal clouding, and damage to the heart and kidneys. Human recombinant alpha-GAL A for use as an enzyme replacement therapy was launched in Japan in April 2004. Eleven ambulatory patients with Fabry's disease were given replacement alpha-GAL A therapy. Three patients died due to factors associated with Fabry's disease. The enzyme replacement therapies in the remaining eight patients continued safely without any notable adverse events. The following were observed: a lowering of the plasma levels of GL-3 in seven cases, an improvement in the daily activities in six cases, and a reduction in corneal clouding in three cases. Although careful observation is necessary, these results suggest that replacement alpha-GAL A therapy may be a safe and effective treatment of Fabry's disease.
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PMID:Enzyme replacement therapy in patients with Fabry's disease. 1769 36

Fabry's disease is a rare X-linked, recessive, glycolipid storage disorder. It is caused by the deficient activity of a lysosomal enzyme, alpha-galactosidase A. Deficiency of alpha-GAL causes an inability to catabolize the lipids with cellular accumulation of its most abundant substrate, globotriaosylceramide (GL-3), and other neutral glycosphingolipids in the vascular endothelium and numerous tissues throughout the body. This progressive glycosphingolipid accumulation leads to life-threatening clinical sequelae in renal, cardiac and cerebrovascular systems. Heterozygous Fabry's disease is less studied. We present a patient, 43 years old, with cardiac (hypertrophic cardiomyopathy), neurological (sensitive-motive polyneuropathy), digestive (chronic diarrheea), renal and cutaneous involvements.
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PMID:Fabry's disease. 1838 22

Fabry disease results from a genetic deficiency of alpha-galactosidase A (alpha GAL) and the impaired catabolism of globotriasoylceramide (GL-3) and other glycosphingolipid substrates, which then accumulate pathogenically within most cells. Enzyme replacement therapy (ERT) with agalsidase beta (Fabrazyme), one of two available forms of recombinant human alpha GAL, involves regular intravenous infusions of the therapeutic protein. Immunoglobulin G (IgG) antibodies to recombinant alpha GAL develop in the majority of patients upon repeated infusion. To explore whether anti-alpha GAL IgG interferes with therapeutic efficacy, retrospective analyses were conducted using data obtained from a total of 134 adult male and female patients with Fabry disease who were treated with agalsidase beta at 1mg/kg every 2 weeks for up to 5 years during placebo-controlled trials and the corresponding open-label extension studies. The analyses did not reveal a correlation between anti-alpha GAL IgG titers and the onset of clinical events or the rate of change in estimated GFR during treatment, and no statistically significant association was found between anti-alpha GAL IgG titers and abnormal elevations in plasma GL-3 during treatment. However, a statistically significant association was found between anti-alpha GAL IgG titers and observation of some GL-3 deposition in the dermal capillary endothelial cells of skin during treatment, suggesting that GL-3 clearance may be partially impaired in some patients with high antibody titers. Determination of the long-term impact of circulating anti-alpha GAL IgG antibodies on clinical outcomes will require continued monitoring, and serology testing is recommended as part of the routine care of Fabry disease patients during ERT.
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PMID:A retrospective analysis of the potential impact of IgG antibodies to agalsidase beta on efficacy during enzyme replacement therapy for Fabry disease. 1906 23

The enzyme alpha-galactosidase (alpha-GAL, also known as alpha-GAL A; E.C. 3.2.1.22) is responsible for the breakdown of alpha-galactosides in the lysosome. Defects in human alpha-GAL lead to the development of Fabry disease, a lysosomal storage disorder characterized by the buildup of alpha-galactosylated substrates in the tissues. alpha-GAL is an active target of clinical research: there are currently two treatment options for Fabry disease, recombinant enzyme replacement therapy (approved in the United States in 2003) and pharmacological chaperone therapy (currently in clinical trials). Previously, we have reported the structure of human alpha-GAL, which revealed the overall structure of the enzyme and established the locations of hundreds of mutations that lead to the development of Fabry disease. Here, we describe the catalytic mechanism of the enzyme derived from x-ray crystal structures of each of the four stages of the double displacement reaction mechanism. Use of a difluoro-alpha-galactopyranoside allowed trapping of a covalent intermediate. The ensemble of structures reveals distortion of the ligand into a (1)S(3) skew (or twist) boat conformation in the middle of the reaction cycle. The high resolution structures of each step in the catalytic cycle will allow for improved drug design efforts on alpha-GAL and other glycoside hydrolase family 27 enzymes by developing ligands that specifically target different states of the catalytic cycle. Additionally, the structures revealed a second ligand-binding site suitable for targeting by novel pharmacological chaperones.
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PMID:Catalytic mechanism of human alpha-galactosidase. 1994 Jan 22


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