Genetic variants of unknown significance in alpha-galactosidase A: Cellular delineation from Fabry disease.

Fabry disease (FD) is an X-linked multiorgan disorder caused by variants in the alpha-galactosidase A gene (GLA). Depending on the variant, disease phenotypes range from benign to life-threatening. More than 1000 GLA variants are known, but a link between genotype and phenotype in FD has not yet been established for all. p.A143T, p.D313Y, and p.S126G are frequent examples of variants of unknown significance (VUS). We have investigated the potential pathogenicity of these VUS combining clinical data with data obtained in human cellular in vitro systems. We have analyzed four different male subject-derived cell types for alpha-galactosidase A enzyme (GLA) activity and intracellular Gb3 load. Additionally, Gb3 load in skin tissue as well as clinical data were studied for correlates of disease manifestations. A reduction of GLA activity was observed in cells carrying p.A143T compared with controls (p < 0.05). In cells carrying the p.D313Y variant, a reduced GLA activity was found only in endothelial cells (p < 0.01) compared with controls. No pathological changes were observed in cells carrying the p.S126G variant. None of the VUS investigated caused intracellular Gb3 accumulation in any cell type. Our data of aberrant GLA activity in cells of p.A143T hemizygotes and overall normal cellular phenotypes in cells of p.D313Y and p.S126G hemizygotes contribute a basic science perspective to the clinically highly relevant discussion on VUS in GLA.

Frequency of Fabry disease in chronic kidney disease patients including patients on renal replacement therapy in Korea.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by the deficient activity of α-galactosidase (α-Gal A), affecting multiple organs including kidney. In this study, we aimed to determine the prevalence of FD in patients with chronic kidney disease (CKD) including those on renal replacement therapy in Korea. METHODS: This is a national, multicenter, observational study performed between August 24, 2017 and February 28, 2020. Patients with the presence of proteinuria or treated on dialysis were screened by measuring the α-Gal A enzyme activity using either dried blood spot or whole blood, and plasma globotriaosylsphingosine (lyso-GL3) concentration. A GLA gene analysis was performed in patients with low α-Gal A enzyme activity or increased plasma lyso-GL3 concentration. RESULTS: Of 897 screened patients, 405 (45.2%) were male and 279 (31.1%) were on dialysis. The α-Gal A enzyme activity was measured in 891 patients (99.3%), and plasma lyso-GL3 concentration was measured in all patients. Ten patients were eligible for a GLA gene analysis: eight with low α-Gal A enzyme activity and two with increased plasma lyso-GL3 concentration. The GLA mutations were analyzed in nine patients and one patient was found with a pathogenic mutation. Therefore, one patient was identified with FD, giving a prevalence of 0.1% (1 of 897) in this CKD population. CONCLUSION: Although the prevalence of FD in the CKD population was low (0.1%), screening tests are crucial to detect potential diseases in patients with relatives who can benefit from early treatment.

Head-to-head trial of pegunigalsidase alfa versus agalsidase beta in patients with Fabry disease and deteriorating renal function: results from the 2-year randomised phase III BALANCE study.

BACKGROUND: Pegunigalsidase alfa is a PEGylated α-galactosidase A enzyme replacement therapy. BALANCE (NCT02795676) assessed non-inferiority of pegunigalsidase alfa versus agalsidase beta in adults with Fabry disease with an annualised estimated glomerular filtration rate (eGFR) slope more negative than -2 mL/min/1.73 m2/year who had received agalsidase beta for ≥1 year. METHODS: Patients were randomly assigned 2:1 to receive 1 mg/kg pegunigalsidase alfa or agalsidase beta every 2 weeks for 2 years. The primary efficacy analysis assessed non-inferiority based on median annualised eGFR slope differences between treatment arms. RESULTS: Seventy-seven patients received either pegunigalsidase alfa (n=52) or agalsidase beta (n=25). At baseline, mean (range) age was 44 (18-60) years, 47 (61%) patients were male, median eGFR was 74.5 mL/min/1.73 m2 and median (range) eGFR slope was -7.3 (-30.5, 6.3) mL/min/1.73 m2/year. At 2 years, the difference between median eGFR slopes was -0.36 mL/min/1.73 m2/year, meeting the prespecified non-inferiority margin. Minimal changes were observed in lyso-Gb3 concentrations in both treatment arms at 2 years. Proportions of patients experiencing treatment-related adverse events and mild or moderate infusion-related reactions were similar in both groups, yet exposure-adjusted rates were 3.6-fold and 7.8-fold higher, respectively, with agalsidase beta than pegunigalsidase alfa. At the end of the study, neutralising antibodies were detected in 7 out of 47 (15%) pegunigalsidase alfa-treated patients and 6 out of 23 (26%) agalsidase beta-treated patients. There were no deaths. CONCLUSIONS: Based on rate of eGFR decline over 2 years, pegunigalsidase alfa was non-inferior to agalsidase beta. Pegunigalsidase alfa had lower rates of treatment-emergent adverse events and mild or moderate infusion-related reactions. TRIAL REGISTRATION NUMBER: NCT02795676.

Concurrent fabry disease and immunoglobulin a nephropathy: a case report.

BACKGROUND: Fabry disease (FD) is an X-linked, hereditary dysfunction of glycosphingolipid storage caused by mutations in the GLA gene encoding alpha-galactosidase A enzyme. In rare cases, FD may coexist with immunoglobulin A nephropathy (IgAN). We describe a case of concurrent FD, IgAN, and dilated cardiomyopathy-causing mutations in the TTN and BAG3 genes, which has not been reported previously. CASE PRESENTATION: A 60-year-old female patient was admitted with a one-week history of facial and lower-limb edema, two-year history of left ventricular hypertrophy and sinus bradycardia, and recurring numbness and pain in three lateral digits with bilateral thenar muscle atrophy. Renal biopsy revealed concurrent FD (confirmed via an alpha-galactosidase A enzyme assay, Lyso-GL-3 quantification, and GLA gene sequencing) and IgAN. Heterozygous mutations in the TTN (c.30,484 C > A;p.P10162T) and BAG3 (c.88 A > G;p.I30V) genes were observed. The patient reported that two of her brothers had undergone kidney transplantation; one died suddenly at 60 years of age, and the other required a cardiac pacemaker. The 35-year-old son of the patient was screened for the GLA gene mutation and found to be positive for the same mutation as the patient. The patient was administered oral losartan (50 mg/day). Enzyme replacement therapy was refused due to financial reasons. Her renal and cardiac functions were stable yet worth closely monitoring during follow-up. CONCLUSION: The family history of patients with concurrent heart and renal diseases should be assessed in detail. Genetic testing and histological examinations are essential for diagnosing FD with IgAN.

Diagnosing Fabry nephropathy: the challenge of multiple kidney disease.

Fabry disease (FD) is an X-linked inherited lysosomal disorder due to a deficiency of the enzyme alpha-galactosidase A (α-gla) due to mutations in the GLA gene. These mutations result in plasma and lysosome accumulation of glycosphingolipids, leading to progressive organ damage and reduced life expectancy. Due to the availability of specific disease-modifying treatments, proper and timely diagnosis and therapy are essential to prevent irreversible complications. However, diagnosis of FD is often delayed because of the wide clinical heterogeneity of the disease and multiple organ involvement developing in variable temporal sequences. This observation is also valid for renal involvement, which may manifest with non-specific signs, such as proteinuria and chronic kidney disease, which are also common in many other nephropathies. Moreover, an additional confounding factor is the possibility of the coexistence of FD with other kidney disorders. Thus, suspecting and diagnosing FD nephropathy in patients with signs of kidney disease may be challenging for the clinical nephrologist. Herein, also through the presentation of a unique case of co-occurrence of autosomal dominant polycystic kidney disease and FD, we review the available literature on cases of coexistence of FD and other renal diseases and discuss the implications of these conditions. Moreover, we highlight the clinical, laboratory, and histological elements that may suggest clinical suspicion and address a proper diagnosis of Fabry nephropathy.

Radiosynthesis and Early Evaluation of a Positron Emission Tomography Imaging Probe [18F]AGAL Targeting Alpha-Galactosidase A Enzyme for Fabry Disease.

Success of gene therapy relies on the durable expression and activity of transgene in target tissues. In vivo molecular imaging approaches using positron emission tomography (PET) can non-invasively measure magnitude, location, and durability of transgene expression via direct transgene or indirect reporter gene imaging in target tissues, providing the most proximal PK/PD biomarker for gene therapy trials. Herein, we report the radiosynthesis of a novel PET tracer [18F]AGAL, targeting alpha galactosidase A (α-GAL), a lysosomal enzyme deficient in Fabry disease, and evaluation of its selectivity, specificity, and pharmacokinetic properties in vitro. [18F]AGAL was synthesized via a Cu-catalyzed click reaction between fluorinated pentyne and an aziridine-based galactopyranose precursor with a high yield of 110 mCi, high radiochemical purity of >97% and molar activity of 6 Ci/µmol. The fluorinated AGAL probe showed high α-GAL affinity with IC50 of 30 nM, high pharmacological selectivity (≥50% inhibition on >160 proteins), and suitable pharmacokinetic properties (moderate to low clearance and stability in plasma across species). In vivo [18F]AGAL PET imaging in mice showed high uptake in peripheral organs with rapid renal clearance. These promising results encourage further development of this PET tracer for in vivo imaging of α-GAL expression in target tissues affected by Fabry disease.

Consensus recommendations for the treatment and management of patients with Fabry disease on migalastat: a modified Delphi study.

Objective: Fabry disease is a progressive disorder caused by deficiency of the α-galactosidase A enzyme (α-Gal A), leading to multisystemic organ damage with heterogenous clinical presentation. The addition of the oral chaperone therapy migalastat to the available treatment options for Fabry disease is not yet universally reflected in all treatment guidelines. These consensus recommendations are intended to provide guidance for the treatment and monitoring of patients with Fabry disease receiving migalastat. Methods: A modified Delphi process was conducted to determine consensus on treatment decisions and monitoring of patients with Fabry disease receiving migalastat. The multidisciplinary panel comprised 14 expert physicians across nine specialties and two patients with Fabry disease. Two rounds of Delphi surveys were completed and recommendations on the use of biomarkers, multidisciplinary monitoring, and treatment decisions were generated based on statements that reached consensus. Results: The expert panel reached consensus agreement on 49 of 54 statements, including 16 that reached consensus in round 1. Statements that reached consensus agreement are summarized in recommendations for migalastat treatment and monitoring, including baseline and follow-up assessments and frequency. All patients with Fabry disease and an amenable mutation may initiate migalastat treatment if they have evidence of Fabry-related symptoms and/or organ involvement. Treatment decisions should include holistic assessment of the patient, considering clinical symptoms and organ involvement as well as patient-reported outcomes and patient preference. The reliability of α-Gal A and globotriaosylsphingosine as pharmacodynamic response biomarkers remains unclear. Conclusion: These recommendations build on previously published guidelines to highlight the importance of holistic, multidisciplinary monitoring for patients with Fabry disease receiving migalastat, in addition to shared decision-making regarding treatments and monitoring throughout the patient journey. GRAPHICAL ABSTRACT.

What Is the Role of Sensorineural Hearing Loss in Fabry Disease Screening?

Objective: Fabry disease is a rare hereditary lysosomal storage disease caused by the deficiency of alpha-galactosidase A (α-GLA). Although sensorineural hearing loss is common in Fabry disease, there are no studies in the literature that have screened a population with sensorineural hearing loss for Fabry disease. In this study, we aimed to screen a group of patients who were diagnosed with sensorineural hearing loss and underwent a hearing test for Fabry disease. Methods: One hundred sixty eight patients who were aged 18-75 years and diagnosed with idiopathic hearing loss between July 2019 and January 2020 were included. In male patients, α-GLA enzyme activity was analyzed. Patients with low enzyme activity were identified and genetic testing was performed for mutations in the GLA gene. In females, only genetic testing was performed. Results: Eighty four women and 84 men were included in the study. α-GLA enzyme activity was low in 11 of the 84 male patients (13%). One out of these 11 patients had a gene mutation for Fabry disease. Moreover, four relatives of this index patient were diagnosed with Fabry disease in family screening. GLA gene mutation was also found in one of the 84 female patients. Consequently, two (1.2%) of our 168 patients were diagnosed with Fabry disease by screening with enzyme activity and genetic testing. Conclusion: Our study showed that screening for Fabry disease in patients with idiopathic sensorineural hearing loss without other specific findings might be a useful strategy for detecting new cases.

Assessment of the feed additive consisting of alpha-galactosidase produced by Saccharomyces cerevisiaeCBS 615.94 and endo-1,4-beta-glucanase produced by Aspergillus nigerCBS 120604 (Agal-Pro BL/BL-L®) for use in chickens for fattening, minor poultry species for fattening and chickens reared for laying for the renewal of its authorisation (Kerry Ingredients & Flavours Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Agal-Pro BL/BL-L®. The additive is a preparation of alpha-galactosidase produced by a genetically modified strain of Saccharomyces cerevisiae (CBS 615.94) and endo-1,4-beta-glucanase produced by a non-genetically modified strain of Aspergillus niger (CBS 120604). It is intended to be used as a zootechnical additive (functional group: digestibility enhancers) in chickens for fattening in its solid and liquid forms (Agal-Pro BL® and Agal-Pro BL-L®), and in minor poultry species for fattening and chickens reared for laying only in its solid form (Agal-Pro BL®). The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for the target animals, consumers and the environment under the authorised conditions of use. Regarding user safety, the additive is considered an irritant to the skin and eyes and a dermal sensitiser. Due to the proteinaceous nature of the active substances, it should be considered a respiratory sensitiser. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of Retinal Vessel Tortuosity Index in Patients with Fabry Disease Using Optical Coherence Tomography Angiography (OCTA).

Vessel tortuosity (VT) is a parameter used to assess retinal involvement in patients affected by systemic diseases such as Fabry disease (FD). In this study, we assessed a retinal VT index (VTI) using optical coherence tomography angiography (OCTA) in a group of patients with FD (FD cohort) compared to a healthy control group (HC cohort). This is a single-center, retrospective study analysis of all consecutive patients with genetically tested and confirmed FD who underwent regular ophthalmological visits from December 2017 to January 2020 at the Department of Ophthalmology at the University Hospital of Zurich, Switzerland. VTI was calculated for each OCTA image and the results were compared between FD and HC cohort. A total of 56 participants, 32 (male:female ratio 12:20) in the FD cohort and 24 (male:female ratio 13:11) in the HC cohort. Classic onset was determined in 18 patients. Overall, mean VTI (±SD) was 0.21 (±0.07). Male patients with classic-onset FD had a significantly higher mean VTI (0.33, SD ± 0.35) compared to all other subgroups (p-value < 0.05). Further investigations of retinal VTI in patients with FD could be helpful to use OCTA as a noninvasive screening and follow-up modality to assess disease progression in affected patients.

Late-Stage Fabry Disease With Advanced Cardiomyopathy and Conduction Disorders.

Fabry disease, a well-known X-linked disorder, can present as an elusive late-stage disease in women with challenging limitations to management. Risk stratification of patient populations for genetic testing, early detection, and advances in affordable clinical treatment are on-going. We present a case to further demonstrate the need for continued research. Our case involved advanced complications, including worsening diastolic heart failure and conduction disorders ranging from supraventricular tachycardia to severe heart block. The patient received goal-directed medical therapy as tolerated for her heart failure and ultimately needed a dual-chamber pacemaker with a defibrillator.

Screening for Fabry disease in a series of Parkinson's disease patients and literature review.

BACKGROUND: So far, mutations in genes encoding lysosomal enzymes have been associated with Parkinson's disease (PD). Fabry disease (FD) is an X-linked lysosomal storage disease caused by alpha-galactosidase A (α-GAL) deficiency, leading to deposition of globotriaosylceramide in the nervous system and other organs. We aimed to screen for FD a case series of PD patients from Southern Italy and to review the literature. METHODS: One hundred and forty-four consecutive unrelated PD subjects were enrolled. The α-GAL activity was measured in all men and, in case of pathological values, subsequent determination of globotriaosylsphingosine (lyso-Gb3) and GLA gene sequencing were also performed. All the women underwent GLA gene sequencing. RESULTS: α-GAL levels resulted low in fifteen men, whereas lyso-Gb3 testing showed values within the reference range in all of them. GLA gene variants were not detected in any tested subjects. One pathological study, six case series, and five case reports are currently reported in literature. CONCLUSIONS: The few studies reviewed are heterogeneous, and the results are controversial. An unknown significance variant in GLA gene was detected in PD patients in one large study, whereas decreased α-GAL activity was observed in PD subjects in two other researches, but without confirmation by lyso-Gb3 assessment or genetic analysis. Vascular parkinsonism was associated to FD in five case reports. We found no association between PD and FD in our population. However, it is not possible to draw definitive conclusions due to limited sample size. Furthermore, controls would have been missing in case of a positive finding.

High-risk screening for Fabry disease in hemodialysis patients in Chiba Prefecture, Japan.

BACKGROUND: High-risk screening for Fabry disease in dialysis patients is an effective means for reducing the number of undiagnosed cases. However, such screening has not been conducted in Chiba Prefecture, Japan. Herein, we aimed to estimate the prevalence of Fabry disease among patients undergoing hemodialysis in Chiba Prefecture by high-risk screening using α-galactosidase A (αGal A) activity measurement, and examine the hemodialysis effect on αGal A activity. METHODS: Patients who underwent maintenance hemodialysis at 25 facilities in Chiba Prefecture were recruited. The αGal A activity was measured using the dried blood spot (DBS) test as the first screening. If the enzyme activity was lower than the cut-off, the second screening was performed with the same method before and after dialysis. RESULTS: Overall, 2924 patients (2036 men and 888 women) were included from which 94 cases (45 men and 48 women) showed decreased αGAL activity in the first screening and 3 (two men and one women) in the second screening. Genetic testing was performed in 3 patients, and the c.1078G > A mutation in GLA gene was detected in one male patient (0.03%). There has been a statistically significant decrease in αGal A activity of DBS at post-dialysis compared to that at pre-dialysis (20.5 ± 10.4 pmol/h/disk and 22.7 ± 11.5 pmol/h/disk, p < 0.0001). CONCLUSION: The prevalence of Fabry disease among patients undergoing hemodialysis in Chiba Prefecture was estimated as 0.03%. This is the first time that dialysis has been shown to affect the αGal A activity.

Asn215Ser, Ala143Thr, and Arg112Cys variants in α-galactosidase A protein confer stability loss in Fabry's disease.

Alpha galactosidase A (α-GalA) gene contains nine exons localized at the q-arm of the X chromosome. Generally, an α-GalA enzyme is involved in the removal of galactosyl moieties from the glycoproteins and glycolipids. Dysregulation results in the accumulation of glycoproteins as well as glycolipids in various organs leading to Fabry disease (FD). In this study, we examine the impact of Asn215Ser, Ala143Thr and Arg112Cys variants on the α-GalA protein structure contributing to functional dynamic changes in FD. The seven computational pathogenicity prediction methods were used to predict the effects of these variants on the α-GalA protein. The three-dimensional structure of α-GalA variants was modeled with the Swiss Model and Robetta server and validated using a variety of tools. Then, molecular dynamics (MD) simulation was performed to understand the stability and dynamic behavior of the wild-type and variants structures. Most of our analyzed pathogenicity prediction tools showed that Asn215Ser, Ala143Thr and Arg112Cys variants cause a deleterious effect on the α-GalA protein. Further, MD trajectory analysis showed the destabilizing effect of variants on α-GalA structure based on the root mean square deviation, root mean square fluctuation, solvent accessible surface area, the radius of gyration, hydrogen bond, cluster analysis and PCA analysis. This concludes that the presence of these variants could potentially affect the protein functional process of galactosyl moieties removal which might lead to Fabry disease.Communicated by Ramaswamy H. Sarma.

Fabry disease: Mechanism and therapeutics strategies.

Fabry disease is a monogenic disease characterized by a deficiency or loss of the α-galactosidase A (GLA). The resulting impairment in lysosomal GLA enzymatic activity leads to the pathogenic accumulation of enzymatic substrate and, consequently, the progressive appearance of clinical symptoms in target organs, including the heart, kidney, and brain. However, the mechanisms involved in Fabry disease-mediated organ damage are largely ambiguous and poorly understood, which hinders the development of therapeutic strategies for the treatment of this disorder. Although currently available clinical approaches have shown some efficiency in the treatment of Fabry disease, they all exhibit limitations that need to be overcome. In this review, we first introduce current mechanistic knowledge of Fabry disease and discuss potential therapeutic strategies for its treatment. We then systemically summarize and discuss advances in research on therapeutic approaches, including enzyme replacement therapy (ERT), gene therapy, and chaperone therapy, as well as strategies targeting subcellular compartments, such as lysosomes, the endoplasmic reticulum, and the nucleus. Finally, the future development of potential therapeutic strategies is discussed based on the results of mechanistic studies and the limitations associated with these therapeutic approaches.

Generation of GLA-knockout human embryonic stem cell lines to model peripheral neuropathy in Fabry disease.

Fabry disease is an X-linked glycolipid storage disorder caused by mutations in the GLA gene which result in a deficiency in the lysosomal enzyme alpha galactosidase A (AGA). As a result, the glycolipid substrate Gb3 accumulates in critical tissues and organs producing a progressive debilitating disease. In Fabry disease up to 80% of patients experience life-long neuropathic pain that is difficult to treat and greatly affects their quality of life. The molecular mechanisms by which deficiency of AGA leads to neuropathic pain are not well understood, due in part to a lack of in vitro models that can be used to study the underlying pathology at the cellular level. Using CRISPR-Cas9 gene editing, we generated two clones with mutations in the GLA gene from a human embryonic stem cell line. Our clonal cell lines maintained normal stem cell morphology and markers for pluripotency, and showed the phenotypic characteristics of Fabry disease including absent AGA activity and intracellular accumulation of Gb3. Mutations in the predicted locations in exon 1 of the GLA gene were confirmed. Using established techniques for dual-SMAD inhibition/WNT activation, we were able to show that our AGA-deficient clones, as well as wild-type controls, could be differentiated to peripheral-type sensory neurons that express pain receptors. This genetically and physiologically relevant human model system offers a new and promising tool for investigating the cellular mechanisms of peripheral neuropathy in Fabry disease and may assist in the development of new therapeutic strategies to help lessen the burden of this disease.

Nationwide screening of Fabry disease in patients with hypertrophic cardiomyopathy in Czech Republic.

AIMS: Fabry disease (FD) is a rare X-linked genetic disorder caused by α-galactosidase A (AGALA) deficiency. Whereas 'classic' variant has multisystemic manifestation, the more recently described 'later-onset' variant is characterized by predominant cardiac involvement that often mimics hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Consecutive unrelated patients with HCM were screened for FD in 16 (out of 17) cardiac centres in the Czech Republic covering specialized cardiology care from June 2017 to December 2018. AGALA activity and globotriaosylsphingosine (lyso-Gb3 ) levels were measured in all subjects using the dry blood spot method. FD was suspected in male patients with AGALA activity <1.2 µmol/h/L and in females with either low AGALA activity or lyso-Gb3  > 3.5 ng/mL. Positive screening results were confirmed by genetic testing. We evaluated 589 patients (390 males, 66%) with HCM (mean maximal myocardial thickness 19.1 ± 4.3 mm). The average age was 58.4 ± 14.7 years. In total, 17 patients (11 males, 6 females) had a positive screening result, and subsequently, six of them (four males and two females) had a genetically confirmed pathogenic GLA mutation (total prevalence of 1.02%). Five of these patients were carrying the p.N215S mutation known to cause a typical later-onset cardiac FD. CONCLUSIONS: We confirmed the prevalence of FD repeatedly reported in previous screening programmes (approximately 1% irrespective of gender) in a non-selected HCM population in Central Europe. Our findings advocate a routine screening for FD in all adult patients with HCM phenotype including both genders. The dry blood spot method used led to identification of clearly pathogenic variants.

Screening for Fabry disease in Argentina in male patients with chronic kidney disease at all stages.

We report three patients diagnosed with Fabry disease through a screening study which included individuals suffering from chronic kidney disease (CKD) at any stage. The study recruited 1740 male patients, and three Fabry patients were diagnosed, resulting in a frequency of 0.17%. The analysis by CKD stage group revealed frequencies of 3.03%, 0.77% and 0.17%, in CKD1, CKD3 and CKD5, respectively. Pedigree analysis was carried out for these families, with a high ratio index: pedigree (1:16). This study underlines the importance of considering Fabry disease in the differential diagnosis at every stage of CKD, including the early ones, and stresses the possibility of finding patients with late onset phenotypes.