Classic Fabry Disease Phenotype Research Articles

Morphological Hallmarks of Classical Fabry Disease: An Ultrastructural Study in a Large Spanish Family.

Fabry disease (FD) is a rare lysosomal disorder caused by α-galactosidase A deficiency, and it leads to the systemic deposition of globotriasylceramide. Demonstrations of the storage material in biopsies support this diagnosis. We report a histological and ultrastructural study of biopsies that were performed on 11 individuals from a family with the variant p.Gln279Arg in GLA, which is associated with the classical phenotype of Fabry disease. Intralysosomal deposits were found in all biopsies, corresponding to the skin, kidney, and endomyocardium in both sexes and at different ages. In nine of the skin biopsies, deposits were analysed by immunofluorescence and quantified at the ultrastructural level. Then, the findings were compared according to sex, genotype, and treatment. The quantification of the deposits in the skin biopsies revealed a broader involvement in men than in women. A significant clearance of the deposits was observed in one case after treatment. Tissue involvement was remarkable at diagnosis in all individuals. The findings from the skin biopsies were demonstrative of classic FD, thus supporting the diagnosis; repeated biopsy analyses suggested the benefit of early treatment.

LysoGb3 in children under 3 years of age with classic Fabry disease phenotype: Is there a clinical correlation?

LysoGb3 in children under 3 years of age with classic Fabry disease phenotype: Is there a clinical correlation?

Late diagnsis of Fabry disease at the stage of cardiac involvement

A clinical case report of late diagnosis (in relation to clinical manifestation) of the classic phenotype of Fabry disease in patient with cardiac involvement: phenocopy of hypertrophy cardiomyopathy, cardiac arrhythmias and conduction abnormalities.

Fabry Disease practice resource: Focused revision

Fabry Disease practice resource: Focused revision

Upregulation of ASIC1a channels in an in vitro model of Fabry disease

Neuropathic pain is one of the key features of the classical phenotype of Fabry disease (FD). Acid sensing ion channels (ASICs) are H+-gated cation channels, which belong to the epithelial sodium channel/DeGenerin superfamily, sensitive to the diuretic drug Amiloride. Molecular cloning has identified several distinct ASIC subunits. In particular the ASIC1a subunit has been associated to pain and its upregulation has been documented in animal models of pain. We analyzed the expression of ASIC1a channels in cellular models that mimic the accumulation of glycosphingolipids in FD (FD-GLs) like Gb3, and LysoGb3. We used mouse primary neurons from brain cortex and hippocampus -supraspinal structures that accumulate FD-GLs-, as well as HEK293 cells. Incubation with Gb3, lysoGb3 and the inhibitor (1-deoxy-galactonojirymicin, DJG) of the enzyme α-galactosidase A (Gla) lead to the upregulation of ASIC1a channels. In addition, activation of ASIC1a results in the activation of the MAPK ERK pathway, a signaling pathway associated with pain. Moreover, accumulation of glycosphingolipids results in activation of ERK, an effect that was prevented by blocking ASIC1a channels with the specific blocker Psalmotoxin. Our results suggest that FD-GLs accumulation and triggering of the ERK pathway via ASIC channels might be involved in the mechanism responsible for pain in FD, thus providing a new therapeutic target for pain relief treatment.

Efficacy of the pharmacologic chaperone migalastat in a subset of male patients with the classic phenotype of Fabry disease and migalastat-amenable variants: data from the phase 3 randomized, multicenter, double-blind clinical trial and extension study

PurposeOutcomes in patients with Fabry disease receiving migalastat during the phase 3 FACETS trial (NCT00925301) were evaluated by phenotype. MethodsData were evaluated in two subgroups of patients with migalastat-amenable GLA variants: “classic phenotype” (n=14; males with residual peripheral blood mononuclear cell α-galactosidase A <3% normal and multiorgan system involvement) and “other patients” (n=36; males not meeting classic phenotype criteria and all females). Endpoints included estimated glomerular filtration rate (eGFR), left ventricular mass index (LVMi), Gastrointestinal Symptoms Rating Scale diarrhea subscale (GSRS-D), renal peritubular capillary (PTC) globotriaosylceramide (GL-3) inclusions, and plasma globotriaosylsphingosine (lyso-Gb3). ResultsBaseline measures in the classic phenotype patients suggested a more severe phenotype. At month 24, mean (SD) annualized change in eGFRCKD-EPI with migalastat was −0.3 (3.76) mL/min/1.73m2 in the classic phenotype subgroup; changes in LVMi, GSRS-D, and lyso-Gb3 were −16.7 (18.64) g/m2, −0.9 (1.66), and −36.8 (35.78) nmol/L, respectively. At month 6, mean PTC GL-3 inclusions decreased with migalastat (−0.8) and increased with placebo (0.3); switching from placebo to migalastat, PTC inclusions decreased by −0.7. Numerically smaller changes in these endpoints were observed in the other patients. ConclusionMigalastat provided clinical benefit to patients with Fabry disease and amenable variants, regardless of disease severity.

Identification of a novel GLA mutation in a family with classical phenotype of Fabry disease

Identification of a novel GLA mutation in a family with classical phenotype of Fabry disease

Clinical, serum lyso-Gl3 and kidney histological findings in 14 pediatric patients with classic phenotype of Fabry disease: Is it possible a correlation?

The Advisory Committee on Vaccines of the Spanish Association of Paediatrics annually publishes the immunisation schedule considered optimal for children resident in Spain, according to available evidence on current vaccines.As regards funded immunisations, the 2 + 1 strategy (2, 4, 11 months) with hexavalent (DTPa-IPV-Hib-HB) and 13-valent pneumococcal vaccines are recommended.Administration of the 6-year booster dose with DTPa is recommended, with a poliomyelitis dose for children who had received the 2 + 1 scheme, as well as Tdap vaccine for adolescents and pregnant women in every pregnancy between 27 and 32 weeks gestation.The 2-dose scheme should be used for MMR (12 months and 3–4 years) and varicella (15 months and 3–4 years). MMRV vaccine could be applied as the second dose.Vaccination against HPV is recommended in both genders, preferably at 12 years of age. A stronger effort should be made to improve vaccination coverage. The new 9-valent vaccine is now available, expanding the coverage for both genders.Tetravalent meningococcal vaccine (MenACWY) is recommended at 12 months and 12-14 years, with a catch-up up at 19 years of age. It is also recommended in infants older than 6 weeks of age with risk factors, or travellers to countries with high incidence of ACWY meningococcal serogroups.As regards non-funded immunisations, meningococcal B vaccination is recommended, with a 2 + 1 schedule, and requests that it be included in the National Immunisation Programme. Vaccination against rotavirus is recommended in all infants.El Comité Asesor de Vacunas de la Asociación Española de Pediatría publica anualmente el calendario de vacunaciones que estima idóneo para los niños residentes en España, teniendo en cuenta la evidencia disponible.En cuanto a las vacunas financiadas, se recomienda emplear el esquema 2 + 1 (2, 4 y 11 meses) con vacunas hexavalentes (DTPa-VPI-Hib-HB) y con antineumocócica conjugada 13-valente.Se aconseja un refuerzo a los 6 años, preferentemente con DTPa, junto con una dosis de polio para aquellos que recibieron esquemas 2 + 1, así como vacunación con Tdpa en adolescentes y en cada embarazo, entre la semana 27 y la 32.Se emplearán esquemas de 2 dosis para triple vírica (12 meses y 3-4 años) y varicela (15 meses y 3-4 años). La segunda dosis se podría aplicar como vacuna tetravírica.Se recomienda vacunación sistemática universal frente al VPH, tanto a chicas como a chicos, preferentemente a los 12 años, debiéndose realizar un mayor esfuerzo para mejorar las coberturas. La nueva vacuna de 9 genotipos amplía la cobertura para ambos sexos.Se recomienda que la vacuna antimeningocócica conjugada tetravalente (MenACWY) se introduzca en el calendario financiado a los 12 meses y a los 12-14 años, aconsejándose un rescate hasta los 19 años. Igualmente, se recomienda en los mayores de 6 semanas de edad con factores de riesgo o que viajen a países de elevada incidencia de estos serogrupos.Respecto a las vacunas no financiadas, se recomienda la antimeningocócica B, con esquema 2 + 1, solicitando su entrada en el calendario. Es recomendable vacunar a todos los lactantes frente al rotavirus.

Identification of a Missense Mutation in the α-galactosidase A Gene in a Chinese Family with Fabry Disease.

Introduction: Fabry Disease (FD), the second most common lysosomal storage disorder after Gaucher disease, is characterized by variable clinical manifestations, including angiokeratoma, corneal dystrophy, recurrent episodes of extremity pain, renal impairment, cardiac complications and cerebrovascular manifestations. It is caused by mutations in the α-galactosidase A gene (gene symbol GLA) on chromosome Xq22, which leads to deficiency of lysosomal α-galactosidase A (α-Gal A), and subsequent accumulation of glycosphingolipids in various tissues and organs. The aim of this study is to identify the disease-causing mutation in a five-generation Chinese family with FD. A c.782G>T transversion (p.G261V) in the GLA gene was identified in four patients and two asymptomatic carriers by direct sequencing, and it co-segregated with the disease in the family. The variant is predicted to be disease-causing mutation and result in seriously abnormal function of α-Gal A. Four patients in this family present with classic phenotype of FD, including acroparesthesias, hypohidrosis, angiokeratomas and intermittent burning pain in extremity.Conclusion: The disease severity is similar among male and female patients. Our study extends the genotype-phenotype relationship between mutations in the GLA gene and clinical findings of FD, which may be helpful in the genetic counseling of patients with FD.

Fabry disease due to D313Y and novel GLA mutations

ObjectivesOur aim is to report four novel α-gal A gene (GLA) mutations resulting in Fabry disease (FD) and provide evidence of pathogenicity of the D313Y mutation regarding which contradictory data...

Mutational analysis of the GLA gene in Mexican families with Fabry disease.

Fabry disease (FD) is a lysosomal storage disorder, which develops due to a deficiency in the hydrolytic enzyme, α-galactosidase A (α-Gal A). Alpha-Gal A hydrolyzes glycosphingolipid globotriaosylceramide (Gb3), and an α-Gal A deficiency leads to Gb3 accumulation in tissues and cells in the body. This pathology is likely to involve multiple systems, but it is generally considered to affect primarily vascular endothelium. In this study, we investigated mutations in the GLA gene, which encodes α-Gal A, in Mexican families with FD. We included seven probands with FD that carried known mutations. We analysed pedigrees of the probands, and performed molecular screening in 65 relatives with the potential of carrying a GLA mutation. Five mutations (P40S, IVS4+4, G328V, R363H, R404del) were detected in seven unrelated Mexican families with the classic FD phenotype. Of the 65 relatives examined, 42 (64.6%) had a GLA gene mutation. In summary, among seven Mexican probands with FD, 65 relatives were at risk of carrying a known GLA mutation, and molecular screening identified 42 individuals with the mutation. Thus, our findings showed that it is important to perform molecular analysis in families with FD to detect mutations and to provide accurate diagnoses for individuals that could be affected.

Disease Progression Modeling to Evaluate the Effects of Enzyme Replacement Therapy on Kidney Function in Adult Patients with the Classic Phenotype of Fabry Disease

Background/Aims: Fabry disease (FD) is a rare inherited lysosomal storage disease with common and serious kidney complications. Enzyme replacement therapies (ERT) with agalsidase-α and -β were investigated to characterize their therapeutic effect on kidney function in FD patients with Classic phenotype. Methods: The prospective FD cohort consisted of 98 genetically confirmed patients (females, n = 61, males, n = 37). The median [interquartile range] follow-up time (time difference from first to last visit) was 9 [6, 12] years. The median age of ERT start was 36 [21 – 54] years for females and 39 [28 – 49] years for males. Results: A disease progression model was developed to (i) characterize the time course of estimated glomerular filtration rate (eGFR) and (ii) evaluate therapeutic effects of ERT on kidney function. Change in eGFR over time was best described by the linear model. Females had stable kidney function with and without ERT (eGFR slopes of -0.07 ml/min/1.73m^2 per year and 0.52 ml/min/1.73m^2 per year, respectively). Males with ERT showed an eGFR decrease of -3.07 ml/min/1.73m^2 per year. Conclusion: Mathematical disease progression modeling indicates that there is no clear therapeutic effect of ERT on kidney function in adult patients with Classic Phenotype of FD. Interpretation of these findings should take into account that the study is not randomized and lacks a placebo controlled group. Further investigations are warranted to clarify whether earlier ERT initiation before 18 years of age, higher ERT dose or more intensive therapies can preserve kidney function.

Skin Globotriaosylceramide 3 Load Is Increased in Men with Advanced Fabry Disease.

BackgroundThe X-chromosomally linked life-limiting Fabry disease (FD) is associated with deposits of the sphingolipid globotriaosylceramide 3 (Gb3) in various tissues. Skin is easily accessible and may be used as an additional diagnostic and follow-up medium. Our aims were to visualize skin Gb3 deposits in FD patients applying immunofluorescence and to determine if cutaneous Gb3 load correlates with disease severity.MethodsAt our Fabry Center for Interdisciplinary Therapy we enrolled 84 patients with FD and 27 healthy controls. All subjects underwent 5-mm skin punch biopsy at the lateral lower leg and the back. Skin samples were processed for immunohistochemistry using antibodies against CD77 (i.e. Gb3). Cutaneous Gb3 deposition was quantified in a blinded manner and correlated to clinical data.ResultsWe found that Gb3 load was higher in distal skin of male FD patients compared to healthy controls (p<0.05). Men (p<0.01) and women (p<0.05) with a classic FD phenotype had higher distal skin Gb3 load than healthy controls. Men with advanced disease as reflected by impaired renal function, and men and women with small fiber neuropathy had more Gb3 deposits in distal skin samples than males with normal renal function (p<0.05) and without small fiber neuropathy. Gb3 deposits were not different between patients with and without enzyme replacement therapy.ConclusionsImmunofluorescence on minimally invasive skin punch biopsies may be useful as a tool for assessment and follow-up in FD patients.

Recommendations for enzyme replacement therapy in classical phenotype of Fabry disease in Latin America

We evaluated the performance of triplex tandem mass spectrometry (MS/MS) assays using dried blood spots (DBSs) to screen for 3 lysosomal storage disorders (LSDs): Pompe, Fabry, and Gaucher diseases.An Acquity UPLC CSH C18 column (Waters) and a TQD triple quadrupole mass spectrometer (Waters) in the multiple reaction monitoring (MRM) mode were used to evaluate the precision, carryover, and ion suppression of 3 enzyme assays (acid alpha glucosidase, acid α-galactosidase, and acid β-glucocerebrosidase) and were used to screen 1606 anonymous newborn DBSs.Intra- and inter-run CVs were between 0 and 14.1% and, between 0 and 18.9%. The carryover was 0%, − 0.14%, and 0.39% for the 3 enzyme activities, respectively. No ion suppression was observed. The data from the 1606 anonymous newborn DBSs exhibited approximately bell-shaped distributions of 3 enzymatic activities (the median values were 16.46 μmol/h/l, 7.25 μmol/h/l, and 25.63 μmol/h/l, respectively).The performance of the triplex tandem mass spectrometry assays for the screening of 3 lysosomal storage disorders in a Korean population using DBSs was acceptable.

Identification and Clinical Characterization of a Novel Alpha-Galactosidase A Mutation

Fabry disease (FD) is an inborn error of metabolism characterized by deficient/absent activity of lysosomal enzyme alpha-galactosidase A, which results in systemic accumulation of glycosphingolipids and progression to renal failure, heart and cerebrovascular disease, and small-fiber peripheral neuropathy. This article describes a Brazilian family affected by FD caused by a novel mutation in exon 6 of the alpha-galactosidase A (GLA) gene (c.812G>C). Signs and symptoms identified were pain crisis, acroparesthesia, hypohidrosis, abdominal cramps and diarrhea, chronic kidney disease, cornea verticillata, left ventricular hypertrophy, and complete heart block. Headache was a common complaint and 1 of the patients presented with aseptic meningitis. The novel missense mutation in the GLA gene identified in this Brazilian family is consistent with the classic FD phenotype.

Overlooked Signs and Symptoms: Lung

The classic phenotype of Fabry disease is a multisystemic disorder affecting many organ systems. Although most severe complications include renal, cardiac, and cerebrovascular events, lung disease associated with α-galactosidase deficiency may significantly contribute to disease burden.

P07—Ventricular Arrhythmias are the Major Cause of Death in Patients With the Classical Phenotype of Fabry Disease

0.3 mg/kg back to 1 mg/kg, the normal approved dose for agalsidase beta. The patient immediately felt more at ease and was less anxious with this higher dose. His neuropathic pain has ceased, and the GL-3 levels normalized again: plasma GL-3 was 4.4 mol/mL, and urinary GL-3/creatinine was 0.8 mol/mol. Conclusions: Agalsidase beta at 1 mg/kg is the correct dose for this Fabry patient, who received this dose for years without any adverse events. A dose decrease imposed by delivery issues rendered the patient anxious and increased his neuropathic pain. Moreover, the urinary GL-3 increased dramatically. This suggests increased disease activity. When the 1-mg/kg dose could be reinitiated, the patient reported a clear improvement of anxiety and neuropathic pain. GL-3 levels normalized again. These observations emphasize the importance of a correct dose of 1 mg/kg to control disease activity in our patient.

Clinical manifestations and mutation study in 16 Chinese patients with Fabry disease

To investigate the clinical manifestations and to characterize mutations of the GLA gene in Chinese patients with Fabry disease so to enhance the diagnosis of Fabry disease. Sixteen Chinese affected males (from 16 unrelated families) with the classic phenotype of Fabry disease were investigated. The patients were diagnosed by a deficiency of alpha-galactosidase A (alpha-Gal A) activity. All seven exons and the neighboring intronic sequences of GLA gene were analyzed by PCR amplification and automated sequencing. A total of 14 mutations were identified including 12 single-base substitutions (11 missense and 1 nonsense mutations), 1 small deletion and 1 splicing mutation. Eight novel mutations (c.119 C > A, c.275 A > T, c.520T > C, c.547G > C, c.647A > G, c.929T > G, c.1045T > A, IVS1-1G > A) were identified. The novel mutations were not tested by RFLP on 100 GLA alleles in Chinese population, and were highly conservative in mammalian species. Fabry disease is often misdiagnosed in China. There is no hot spot for mutations in Chinese patients. GLA gene mutation analysis is a reliable method to diagnosis for Fabry disease.

Bone and joint involvement in Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disease caused by deficient activity of the enzyme α-galactosidase A. Although the disease has progressive effects on most organ systems in the body, data is limited regarding skeletal involvement in this rare disorder. We describe four family-related patients, three men and one premenopausal female, sharing a classic phenotype of FD. Dual-energy X-ray was performed in all cases and osteoporosis or osteopenia were found in all patients and osteoporotic fractures in one. One patient also showed both neuropathic joint disease and osteonecrosis. Several mechanisms that may explain osteoporosis and osteoarthropathy in the setting of FD are emphasized.

High Incidence of Later-Onset Fabry Disease Revealed by Newborn Screening

The classic phenotype of Fabry disease, X-linked alpha -galactosidase A (alpha -Gal A) deficiency, has an estimated incidence of approximately 1 in 50,000 males. The recent recognition of later-onset variants suggested that this treatable lysosomal disease is more frequent. To determine the disease incidence, we undertook newborn screening by assaying the alpha-Gal A activity in blood spots from 37,104 consecutive Italian male neonates. Enzyme-deficient infants were retested, and "doubly screened-positive" infants and their relatives were diagnostically confirmed by enzyme and mutation analyses. Twelve (0.03%) neonates had deficient alpha-Gal A activities and specific mutations, including four novel missense mutations (M51I, E66G, A73V, and R118C), three missense mutations (F113L, A143T, and N215S) identified previously in later-onset patients, and one splicing defect (IVS5(+1G-->T)) reported in a patient with the classic phenotype. Molecular modeling and in vitro overexpression of the missense mutations demonstrated structures and residual activities, which were rescued/enhanced by an alpha-Gal A-specific pharmacologic chaperone, consistent with mutations that cause the later-onset phenotype. Family studies revealed undiagnosed Fabry disease in affected individuals. In this population, the incidence of alpha-Gal A deficiency was 1 in approximately 3,100, with an 11 : 1 ratio of patients with the later-onset : classic phenotypes. If only known disease-causing mutations were included, the incidence would be 1 in approximately 4,600, with a 7 : 1 ratio of patients with the later-onset : classic phenotypes. These results suggest that the later-onset phenotype of Fabry disease is underdiagnosed among males with cardiac, cerebrovascular, and/or renal disease. Recognition of these patients would permit family screening and earlier therapeutic intervention. However, the higher incidence of the later-onset phenotype in patients raises ethical issues related to when screening should be performed--in the neonatal period or at early maturity, perhaps in conjunction with screening for other treatable adult-onset disorders.