Purpose: To determine the impact of initiating enzyme replacement therapy (ERT) with agalsidase alfa early in the course of Fabry disease, we evaluated renal and cardiac outcomes for <= 10 years after ERT initiation in males from the Fabry Outcome Survey (FOS). Patients and Methods: Male patients from FOS were stratified into three cohorts by age at ERT initiation: <= 18 years (cohort 1), >18 and <= 30 years (cohort 2), and >30 years (cohort 3). Analysis included age at symptom onset, diagnosis, and ERT initiation; ERT duration; FOS-Mainz Severity Score Index (FOS-MSSI); estimated glomerular filtration rate (eGFR); proteinuria level; and left ventricular mass indexed to height (LVMI). Mixed-effect models estimated renal and cardiac outcomes during follow-up between and within cohorts. Findings: The analysis included 560 male patients: 151 (27.0%) in cohort 1, 155 (27.7%) in cohort 2, and 254 (45.4%) in cohort 3. Mean +/- SD duration of ERT for cohorts 1, 2, and 3 was 6.3 +/- 4.3, 8.6 +/- 4.9, and 7.9 +/- 4.9 years, respectively. Mean+SD baseline FOS-MSSI scores increased with age from 9.8 +/- 7.2 in cohort 1 to 24.7 +/- 11.4 in cohort 3. Cohort 3 showed the lowest baseline mean +/- SD value for eGFR (87.1 +/- 29.0 mL/min/1.73m(2)) and highest baseline mean +/- SD values for proteinuria (801.9 +/- 952.6 mg/day) and LVMI (56.7 +/- 16.0 g/m(2)(.7)) among the three cohorts. Evaluation of mean annual rates of change in eGFR, proteinuria, and LVMI revealed no significant differences in any parameter for cohort 1. For cohort 2, proteinuria and LVMI remained stable, whereas eGFR significantly deteriorated annually (-1.12 mL/min/1.73m(2); P<0.001). Cohort 3 demonstrated significant annual deteriorations in eGFR (-2.60 mL/min/1.73m(2); P<0.001), proteinuria (+34.10 mg/day; P<0.001), and LVMI (+0.59 g/m(2.7); P=0.001).

MRI is a helpful tool for monitoring disease progression in late-onset Pompe disease (LOPD). Our study aimed to evaluate if muscle diffusion tensor imaging (mDTI) shows alterations in muscles of LOPD patients with <10% fat-fraction. We evaluated 6 thigh and 7 calf muscles (both legs) of 18 LOPD and 29 healthy controls (HC) with muscle diffusion tensor imaging (mDTI), T1w, and mDixonquant sequences in a 3T MRI scanner. The quantitative mDTI-values axial diffusivity (λ1 ), mean diffusivity (MD), radial diffusivity (RD), and fractional anisotropy (FA) as well as fat-fraction were analyzed. 6-Minute Walk Test (6-MWT) data were correlated to diffusion metrics. We found that mDTI showed significant differences between LOPD and HC in diffusion parameters (P < .05). Thigh muscles with <10% fat-fraction showed significant differences in MD, RD, and λ1-3 . MD positively correlated with 6-MWT (P = .06). To conclude, mDTI reveals diffusion restrictions in muscles of LOPD with and without fat-infiltration and reflects structural changes prior to fatty degeneration.

Fabry's disease (FD) is an X‐linked lysosomal storage disorder caused by the deficient activity of the lysosomal enzyme α‐galactosidase A (α‐Gal A) leading to intracellular accumulation of globotriaosylceramide (Gb3). Patients with amenable mutations can be treated with migalastat, a recently approved oral pharmacologic chaperone to increase endogenous α‐Gal A activity. We assessed safety along with cardiovascular, renal, and patient‐reported outcomes and disease biomarkers in a prospective observational multicenter study after 12 months of migalastat treatment under “real‐world” conditions. Fifty‐nine (28 females) patients (34 (57.6%) pretreated with enzyme replacement therapy) with amenable mutations were recruited. Migalastat was generally safe and well tolerated. Females and males presented with a reduction of left ventricular mass index (primary end point) (−7.2 and −13.7 g/m 2 , P = 0.0050 and P = 0.0061). FD‐specific manifestations and symptoms remained stable (all P > 0.05). Both sexes presented with a reduction of estimated glomerular filtration rate (secondary end point) (−6.9 and −5.0 mL/minute/1.73 m 2 ; P = 0.0020 and P = 0.0004, respectively), which was most prominent in patients with low blood pressure ( P = 0.0271). α‐Gal A activity increased in male patients by 15% from 29% to 44% of the normal wild‐type activity ( P = 0.0106) and plasma lyso‐Gb3 levels were stable in females and males ( P = 0.3490 and P = 0.2009). Reevaluation of mutations with poor biochemical response revealed no marked activity increase in a zero activity background. We conclude that therapy with migalastat was generally safe and resulted in an amelioration of left ventricular mass. In terms of impaired renal function, blood pressure control seems to be an unattended important goal.

Early diagnosis is of substantial benefit for patients with Pompe disease. Yet underdiagnosing and substantial diagnostic delay are still frequent and the determinants of this are unknown. This study is the first to systematically investigate the diagnostic odyssey in Pompe disease from patients', parents', and physicians' perspectives. Patients with infantile or late onset Pompe disease, their parents as well as their metabolic experts were invited to fill in respective surveys. The survey addressed perceived disease symptoms at onset and during the course of the disease, specialties of involved physicians, activities of patient-initiated search for diagnosis and the perceived impact of time to diagnosis on outcome. Results of experts' and patients'/parents' surveys were compared and expressed by descriptive statistics. We collected data on 15 males and 17 females including 9 infantile and 23 late onset Pompe patients. All received the correct diagnosis at a metabolic or musculoskeletal expert center. Patients with direct referral to the expert center had the lowest diagnostic delay, while patients who were seen by several physicians, received the correct diagnosis after 44%-200% longer delay. The proportion of direct referral varied strongly between pediatricians (57%) and other disciplines (18%-36%). Our study highlights a substantially larger diagnostic delay in Pompe patients that are not directly referred to expert centers for diagnostic work. Our findings may be used to develop more successful strategies for early diagnosis. Diagnostic delay in Pompe disease is substantial particularly in patients that are not directly referred to expert centers for diagnostic workup, so facilitating direct referral may be a new strategy for early diagnosis.

Introduction: Fabry disease (FD) is an X-linked disorder that affects both males and females and is caused by deficient activity of the lysosomal enzyme a-galactosidase A (a-Gal A).1 This leads to the accumulation of globotriaosylceramide (GL-3, Gb3), predominantly in the lysosomes of multiple cell types, and the elevation of globotriaosylsphingosine (lyso-GL-3, lyso-Gb3), the more water-soluble deacylated form of GL-3, in the plasma.2

White matter lesions (WML) in younger patients might be due to a variety of neurological disorders. Fabry disease (FD), an x-linked inherited lysosomal storage disorder, happens to be misdiagnosed as multiple sclerosis (MS). In two middle-aged female patients, presenting bilateral WML, diagnosis of MS turned out to be doubtful. Human genetic analysis presented the Fabry mutation D313Y, in which clinical impact is still unclear. Disease manifestations outside the central nervous system were not detected. Our findings support the suspicion that Fabry mutation D313Y may be involved in neural damage resulting in WML.

BACKGROUND:Ocular signs of Fabry disease can be seen in the first decade of life.METHODS:We examined the occurrence of ocular signs in 232 paediatric patients in the Fabry Outcome Survey (FOS) international registry and looked for relationships between the presence of eye findings and disease severity as measured by the FOS Mainz severity score index (FOS-MSSI).RESULTS:At least one ocular sign was found in 55/101 (54.5%) girls and 62/131 (47.3%) boys: cornea verticillata in 53/101 (52.5%) girls and 55/131 (42.0%) boys, vessel tortuosity in 17/98 (17.3%) girls and 32/131 (24.4%) boys, and posterior spoke-like lens opacities in 3/97 (3.1%) girls and 2/130 (1.5%) boys. Summary statistics showed higher median (range) age-adjusted FOS-MSSI total score indicating more severe disease in children with eye findings versus those without eye findings (0.5 [-11.0, 20.7] versus -2.3 [-11.1, 18.8]). At least one eye finding was observed in 59.1% of treated and 37.9% of untreated children.CONCLUSIONS:We conclude that the presence of ocular signs, particularly cornea verticillata, correlates with more severe disease as indicated by FOS-MSSI scores in paediatric patients with Fabry disease. Ocular signs appear in roughly half of school-aged children with Fabry disease and are well-recognised as a valuable tool for diagnosis of Fabry disease in children; they also may help identify patients who are at risk for developing early severe manifestations of Fabry disease and who should be further evaluated and closely followed up.

The aim of the present study was to assess manifestations of and applied treatment concepts for females with Fabry disease (FD) according to the current European Fabry Guidelines.

OBJECTIVES:Although several reports suggest an increased thromboembolic event rate, especially regarding strokes and TIAs at early age in patients with Fabry disease (FD), the risk for patients with FD to experience these events, the clinical relevance of additional risk factors including the concurrence of factor V Leiden (FVL), and the benefit of enzyme replacement therapy (ERT) regarding these events remain unclear.METHODS:Three hundred four consecutively recruited patients with FD were evaluated for their lifetime occurrence of thromboembolic events such as stroke, TIA, deep vein thrombosis, and pulmonary embolism. The thromboembolic risk was determined in patients with FD and concurrent FVL, and the impact of ERT was assessed.RESULTS:The 304 patients with FD had a median age of 41 years and 53 (17.4%) had experienced at least one thromboembolic event during their lifetime. Among 226 patients with FD screened for FVL, 16 gene carriers were identified (7.1%). The occurrence of thromboembolic events in patients with FD and concurrent FVL was significantly increased compared to those without FVL (hazard ratio = 5.45, 95% confidence interval 2.29-12.99; p < 0.001). Patients with FD receiving ERT had a significantly decreased risk of thromboembolic events compared to those without ERT (hazard ratio = 0.362, 95% confidence interval 0.132-0.992; p = 0.0422).CONCLUSION:This observational study confirms that patients with FD have a high risk of clinically relevant thromboembolic events, which could be aggravated by a concurrence of FVL. ERT might be of benefit in preventing vascular events in patients with FD. The latter observation needs confirmation, however, by randomized and controlled clinical trials.

Purpose: Enzyme replacement therapy (ERT) with recombinant human acid α-glucosidase (rhGAA) prolongs survival in infantile Pompe disease (IPD). However, the majority of cross-reactive immunologic material (CRIM)–negative (CN) patients have immune responses with significant clinical decline despite continued ERT. We aimed to characterize immune responses in CN patients with IPD receiving ERT monotherapy. Methods: A chart review identified 20 CN patients with IPD treated with ERT monotherapy for ≥6 months. Patients were stratified by anti-rhGAA antibody titers: high sustained antibody titers (HSAT; ≥51,200) at least twice; low titers (LT; <6,400) throughout treatment; or sustained intermediate titers (SIT; 6,400–25,600). Results: Despite early initiation of treatment, the majority (85%) of CN patients developed significant antibody titers, most with HSAT associated with invasive ventilation and death. Nearly all patients with HSAT had at least one nonsense GAA mutation, whereas the LT group exclusively carried splice-site or frameshift mutations. Only one patient in the HSAT group is currently alive after successful immune modulation in the entrenched setting. Conclusion: Immunological responses are a significant risk in CN IPD; thus induction of immune tolerance in the naive setting should strongly be considered. Further exploration of factors influencing immune responses is required, particularly with the advent of newborn screening for Pompe disease. Genet Med 17 11, 912–918.

Ocular signs in Fabry disease have generally been regarded to be primarily of diagnostic value. We explored whether ocular findings, alone or in particular in combination with the α-galactosidase A gene mutation, have predictive value for disease severity. Data from the Fabry Outcome Survey (FOS), a large, global database sponsored by Shire, were selected for adult patients who had undergone ophthalmological examination. Three ocular signs were assessed: cornea verticillata, tortuous conjunctival and/or retinal vessels, and cataract. Fabry disease severity was measured using FOS Mainz Severity Score Index and modifications thereof. Ophthalmological data were available for 1203 (699 female, 504 male) adult patients with eye findings characteristic of Fabry disease in 55.1%. Cornea verticillata had a similar distribution in women (51.1%) and men (50.8%), whereas tortuous vessels and Fabry cataract were somewhat more frequent in men than in women. Patients with cornea verticillata, selected as the principal ocular sign for this study, had more severe disease (median score, 20.0) versus those without ocular signs (11.0; P<0.001). This finding could be confirmed by applying age adjusted severity scores. Moreover, the prevalence of cornea verticillata was significantly higher in patients with null (male, 76.9%; female, 64.5%) and missense (male, 79.2%; female, 67.4%) mutations versus mild missense (male, 17.1%; female, 23.1%) and the p.N215S (male, 15.0%; female, 15.6%) mutations (P<0.01). Our analyses show a correlation between the prevalence of ocular changes in Fabry disease and disease severity. Consequently, information on ocular findings and α-galactosidase A gene mutation may help assess the risk for more severe Fabry disease. These observed findings are of notable clinical importance, as Fabry disease is characterized by high clinical course variability and only weak genotype-phenotype correlation at the individual patient level. Further confirmatory studies are needed.

Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed to define European consensus recommendations for the initiation and cessation of ERT in patients with FD.