Experience with cascade screening: A comprehensive family pedigree analysis of two index patients with Fabry disease.

The wide range of clinical symptoms observed in patients with Fabry disease (FD) often leads to delays in diagnosis and initiation of treatment. Delayed initiation of therapy may result in end-organ damage, such as chronic renal failure, hypertrophic cardiomyopathy, and stroke. Although some tools are available to identify undiagnosed patients, new comprehensive screening methods are needed. In this study, the outcomes of the cascade screening applied to three index cases with FD from 2 familes were investigated. In the pedigree analysis, 280 individuals were included; out of them, 131 individuals underwent genetic testing and cascade screening for FD. During the screening program, a total of 45 individuals were diagnosed, with a diagnostic ratio of 1:15. The average age at diagnosis for all individuals was 30.9 ± 17.7 years, and %25 were pediatric cases (mean age 9.5 ± 5.9 years). Thirty affected relatives were diagnosed from the two index cases in Family 1 and 15 individuals were diagnosed from one index case in Family 2. There were 13 consanguineous marriages observed among 2 pedigres, in two both spouses  were affected, leading to two homozygous affected daughters in one couple. In regions where there is a high prevalence of consanguineous marriages, implementing the cascade screening approach to identify all individuals at risk can be beneficial for patients with FD, specifically women and children.

Missed diagnosis of Fabry disease: should we screen patients with multiple sclerosis?

INTRODUCTION: Fabry disease (FD) can be undiagnosed in the context of multiple sclerosis (MS) due to similar clinical and paraclinical features. Our study aimed to determine the prevalence (and the necessity of screening) of FD among patients with possible or definite MS. METHODS: In this prospective monocentric observational study, we included consecutive patients enrolled between May 2017 and May 2019 after the first clinical event suggestive of MS. All patients underwent FD screening using dried blood spots in a stepwise manner combining genetic and enzyme testing. Patients were followed until May 2022. RESULTS: We included 160 patients (73.1% female, mean age 33.9 years). The 2017 revised McDonald's criteria for definite MS were fulfilled by 74 (46.3%) patients at the time of study recruitment and 89 (55.6%) patients after 3-5 years of follow-up. None of the patients had a pathogenic GLA variant, and four (2.5%) had a variant of unknown significance (p.A143T, p.S126G, 2 × p.D313Y). In two of these patients, the intrathecal synthesis of oligoclonal bands was absent, and none had hyperproteinorachia or pleocytosis in cerebrospinal fluid. Detailed examination of FD organ manifestations revealed only discrete ocular and kidney involvement in two patients. CONCLUSION: The prevalence of FD in the population of suspected or definite MS patients does not appear to be high. Our results do not support routine FD screening in all patients with a possible diagnosis of MS, but there is an urgent need to search for red flags and include FD in the differential diagnosis of MS.

Prevalence of Fabry disease-causing variants in the UK Biobank.

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder resulting from deficiency of the alpha-galactosidase A enzyme leading to accumulation of globotriaosylceramide in multiple organ sites with prominent cardiovascular and renal involvement. Global prevalence estimates of Fabry disease based on clinical ascertainment range from 1 in 40 000 to 1 in 170 000. We aimed to determine the prevalence of Fabry disease-causing variants in UK Biobank. METHODS: We sought GLA gene variants in exome sequencing data from 200 643 individuals from UK Biobank. We used ACMG/AMP guidelines (American College of Medical Genetics/Association for Molecular Pathology) to classify pathogenicity and compared baseline biomarker data, hospital ICD-10 (International Classification of Diseases version-10) codes, general practitioner records and self-reported health data with those without pathogenic variants. RESULTS: We identified 81 GLA coding variants. We identified eight likely pathogenic variants on the basis of being rare (<1/10 000 individuals) and either previously reported to cause Fabry disease, or being protein-truncating variants. Thirty-six individuals carried one of these variants. In the UK Biobank, the prevalence of likely pathogenic Fabry disease-causing variants is 1/5732 for late-onset disease-causing variants and 1/200 643 for variants causing classic Fabry disease. CONCLUSION: Fabry disease-causing GLA variants are more prevalent in an unselected population sample than the reported prevalence of Fabry disease. These are overwhelmingly variants associated with later onset. It is possible the prevalence of later-onset Fabry disease exceeds current estimates.

Respiratory impairments in patients suffering from Fabry disease - A cross-sectional study.

BACKGROUND: The inherited X-linked disorder, Fabry disease, is caused by deficient lysosomal enzyme α-galactosidase A, with progressive accumulation of globotriaosylceramide in multiple organs including the upper and lower airways. OBJECTIVES: To assess pulmonary function at the time of the first pulmonary function test (PFT) performed among the National Danish Fabry cohort and define the prevalence of affected lung function variables. MATERIALS AND METHOD: A cross-sectional retrospective cohort study of 86 adult patients enrolled in one or both international patient registry databases for Fabry disease, Fabry Registry or FollowME with at least one PFT. The Mainz Severity Score Index (MSSI) was calculated to determine the disease severity. Lung function variables were examined by multivariate regression adjusted for important variables for developing airway illness. RESULTS: Seventeen patients (20%) showed obstructive airflow limitation and 7 (8%) a restrictive lung deficiency. Smoking status (p = .016) and MSSI (p < .001) were associated with increasing obstructive airway limitation. CONCLUSION: The prevalence of affected lung function among the National Danish Fabry cohort was 28%. Patients with classic gene variants frequently developed a decrease in lung function regardless of their smoking status, with significant relationship with disease severity.

Global reach of over 20 years of experience in the patient-centered Fabry Registry: Advancement of Fabry disease expertise and dissemination of real-world evidence to the Fabry community.

Fabry disease (FD, α-galactosidase A deficiency) is a rare, progressive, complex lysosomal storage disorder affecting multiple organ systems with a diverse spectrum of clinical phenotypes, particularly among female patients. Knowledge of its clinical course was still limited in 2001 when FD-specific therapies first became available and the Fabry Registry (NCT00196742; sponsor: Sanofi) was initiated as a global observational study. The Fabry Registry has now been operational for over 20 years, overseen by expert Boards of Advisors, and has collected real-world demographic and longitudinal clinical data from more than 8000 individuals with FD. Leveraging the accumulating evidence base, multidisciplinary collaborations have resulted in the creation of 32 peer-reviewed scientific publications, which have contributed to the greatly expanded knowledge on the onset and progression of FD, its clinical management, the role of sex and genetics, the outcomes of enzyme replacement therapy with agalsidase beta, and prognostic factors. We review how the Fabry Registry has evolved from its inception to become the largest global source of real-world FD patient data, and how the generated scientific evidence has helped to better inform the medical community, individuals living with FD, patient organizations, and other stakeholders. The patient-centered Fabry Registry fosters collaborative research partnerships with the overarching goal of optimizing the clinical management of patients with FD and is well positioned to add to its past achievements.

Prevalence of lymphedema among Anderson-Fabry disease patients: A report from the Fabry registry.

BACKGROUND: Anderson-Fabry disease (AFD) is a rare X-linked lysosomal storage disease due to a genetic variation in the α-galactosidase A (GLA) gene. As a result, the activity of the α-galactosidase A (AGAL-A) enzyme is reduced or absent, which causes sphingolipid deposition within different body parts. AFD typically manifests with cardiovascular, renal, cerebrovascular, and dermatologic involvement. Lymphedema is caused by sphingolipid deposition within lymphatics. Lymphedema can cause intolerable pain and limit daily activities. Very limited data exist on lymphedema in AFD patients. METHODS: Using data from the Fabry Registry (NCT00196742) with 7671 patients included (44% males and 56% females), we analyzed the prevalence of lymphedema among AFD patients who were ever assessed for lymphedema and studied the age of first reported lymphedema. Additionally, we assessed whether patients received AFD-specific treatment at some point during their clinical course. The data was stratified by gender and phenotype. RESULTS: Our study showed that lymphedema occurred in 16.5% of the Fabry Registry patients who were ever assessed for lymphedema (n = 5487). Male patients when compared to female patient have higher prevalence (21.7% vs 12.7%) and experienced lymphedema at a younger age (median age at first reported lymphedema of 43.7 vs 51.7 years). When compared to other phenotypes, classic phenotype has the highest prevalence of lymphedema with the earliest reported lymphedema. Among those who reported lymphedema, 84.5% received AFD-specific treatment during their clinical course. CONCLUSIONS: Lymphedema is a common manifestation of AFD in both genders, with a tendency to present later in female patients. Recognition of lymphedema can offer an important opportunity for intervention and potential impact on associated morbidity. Additional future studies are needed to characterize the clinical implications of lymphedema in AFD patients and identify additional treatment options for this growing population.

Prevalence of Fabry disease in patients with chronic kidney disease: A systematic review and meta-analysis.

Fabry disease (FD) is an X-linked lysosomal storage disease caused by pathogenic variants in the GLA gene. It has a wide range of clinical manifestations, typically related to the specific underlying GLA variant. One of the main features of FD is kidney involvement; therefore, several studies have addressed the prevalence of FD in all types of patients with chronic kidney disease. We performed a systematic review and meta-analysis of screening studies in chronic kidney disease patients, including those on dialysis, had undergone a kidney transplantation, and those who did not receive kidney replacement therapy, and assessed the prevalence of pathogenic variants in these cohorts. Fifty-five studies were included, involving a total of 84,062 individuals. Of these, 251 cases were positive for FD; a third of the reported GLA variants were of a benign phenotype (37.8%), followed by classical phenotype (31.7%), late onset (15.5%), and of uncertain significance (14.7%). The overall prevalence among dialysis patients was 0.10% (CI95%, 0.06-0.15), 0.28% (CI95%, 0.06-0.15) among patients with kidney transplantation, and 0.17% (CI95%, 0.11-0.39) among those without kidney replacement therapy. Although the overall prevalence of FD is low in patients with kidney involvement, screening, especially in patients who have not yet undergone kidney replacement therapy, is important, in order to provide timely and effective treatment interventions, including disease modifying therapies. The prevalence of kidney involvement in females with Fabry Disease is lower but this should not lead to inadequate follow up. Further research is also needed on the impact of genetic variants of uncertain significance to elucidate their role in Fabry disease.

Cluster analysis of kidney function decline among males with Fabry disease in a large United States electronic health records database.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficient α-galactosidase A activity. The spectrum of disease includes phenotypes ranging from "classic" to "later-onset," with varying kidney disease progression. Identifying patterns of declining kidney function and involvement of other major organs in patients with FD is important to guide therapy decisions. METHODS: Clusters of patients with FD and similar estimated glomerular filtration rate (eGFR) decline and age were created using agglomerative clustering of data captured between 2007 and 2020 in the United States Optum Market Clarity database. Male patients with a diagnosis of FD and two or more eGFR values ≥6 months apart were included. Disease progression was compared with a control cohort of patients without an FD diagnosis. RESULTS: eGFR values from 234 male patients with FD were analysed, yielding seven clusters. Five clusters demonstrated disease progression from "natural" eGFR decline, with a slight decrease in kidney function and eGFR usually within the normal range, to rapid, early decline in eGFR and cardiac complications. When compared with the control cohort, a more rapid decline and a higher percentage of cardiac hypertrophy, heart failure, arrhythmias and stroke were noted in the study group. An inflection point was observed in each cluster when deterioration of kidney function accelerated. CONCLUSIONS: Clustering of male patients with FD by decline in kidney function, organ involvement and phenotype through analysis of real-world data provides a reference that could help determine the optimal time for initiation of FD-specific treatment and facilitate management decisions made by healthcare professionals.

Prevalence of papillary muscle hypertrophy in fabry disease.

BACKGROUND AND AIMS: Fabry disease (FD) is an X-linked genetic lysosomal disease, in which a deficit in the alpha-galactosidase A enzyme results in lysosomal build-up of globotriaosylceramide in several organs, causing cardiac, renal and cerebrovascular complications. The aim of this study was to assess the prevalence of papillary muscle hypertrophy (PMH) in patients with FD. METHODS: A group of 63 patients with FD and a positive genetic diagnosis were studied and were divided into two groups: one included 24 patients with FD and LVH and another group included 39 patients with FD and without LVH. Papillary muscles were measured from the left parasternal short axis view, defining PMH as a diastolic thickness greater than 11 mm in any diameter. RESULTS: Patients with FD and LVH had a high prevalence of anterolateral PMH (66.6%), and such prevalence was lower for the posteromedial PMH (33.3%). However, patients who had not yet developed LVH had a high prevalence of anterolateral PMH (33.3%). CONCLUSIONS: Patients with FD in the pre-clinical stage (without LVH) have a high prevalence of PMH, especially involving the anterolateral papillary muscle. This finding could be an early marker for the development of LVH, allowing to suspect the disease during its early stages, and begin enzyme replacement therapy in the appropriate patients.

A nationwide cross-sectional analysis of biopsy-proven Fabry nephropathy: the Japan Renal Biopsy Registry.

BACKGROUND: Fabry disease (FD) is an X-linked inherited disease where renal complications are associated with a poor prognosis. However, little is known about the prevalence of Fabry nephropathy (FN) in patients with chronic kidney disease (CKD). We extracted FN data from the Japan Renal Biopsy Registry, analyzed the prevalence of FN, and examined the correlation between clinical characteristics and renal involvement according to sex differences and hemi- and heterozygosity in patients with FD. METHODS: A total of 38,351 participants who underwent renal biopsy were retrospectively enrolled, and FN was determined. The clinical characteristics of FD patients were examined based on sex differences. RESULTS: Twenty-nine patients (0.076%) (19 males and 10 females, mean age: 43.7 ± 15.5 years old) were diagnosed with FN. Median estimated urinary protein (UP) and mean eGFR levels were 0.9 [interquartile range (IQR) [0.7-1.6] g/gCr and 67.1 ± 36.8 mL/min/1.73 m2, respectively. Mean systolic blood pressure (SBP) was 126.4 ± 17.1 mmHg and diastolic blood pressure was 76.1 ± 12.6 mmHg. An inverse correlation between eGFR and logarithm UP levels was observed (r2 = 0.23, p = 0.02), SBP was positively associated with logarithm UP (r2 = 0.34, p = 0.004) overall and inversely associated with eGFR (r2 = 0.25, p = 0.007) regardless of sex, and SBP was an independent determinant of proteinuria (p = 0.004) and eGFR (p = 0.007). CONCLUSIONS: The prevalence of biopsy-proven FN was 0.076%. Since SBP is associated with eGFR regardless of zygosity, strict SBP control might be necessary to prevent progression to end-stage kidney disease in both male and female patients with FN.

Late-onset fabry disease due to the p.Phe113Leu variant: the first italian cluster of five families.

BACKGROUND: The GLA c.337T > C (p.Phe113Leu) is a known pathogenic variant associated to late-onset Fabry disease phenotype with predominant cardiac manifestations. A founder effect was demonstrated in a large cohort in the Portuguese region of Guimarães. Herein we report an in-depth phenotype description of a cluster of five Southern Italy families. METHODS: Family pedigrees of five index males with the p.Phe113Leu variant were obtained and all at-risk relatives underwent biochemical and genetical screening test. Carriers of GLA p.Phe113Leu variant underwent subsequent multidisciplinary clinical and instrumental evaluation. RESULTS: Thirty-one (16 M, 15 F) individuals with p.Phe113Leu pathogenic variant were identified. Sixteen out of 31 patients (51.6%) had cardiac manifestations. Notably, myocardial fibrosis was found in 7/8 patients, of whom 2 were under 40 years. Stroke occurred in 4 patients. White matter lesions were detected in 12/19 patients and occurred in 2/10 of subjects under 40 years. Seven females complained of acroparesthesias. Renal involvement occurred in 10 patients. Angiokeratomas were evident in 9 subjects. Eyes, ear, gastrointestinal and pulmonary involvement occurred in the minority of subjects. CONCLUSION: This study demonstrates that a cluster of subjects with p.Phe113Leu pathogenic variant is also present in Southern Italy. Disease manifestations are frequent in both sexes and may occur early in life. Cardiac involvement represents the core manifestation, but neurological and renal involvement is also frequent, suggesting that extra-cardiac complications deserve clinical attention.

Ocular findings and their correlation with disease severity in Fabry disease in South-East Anatolia.

PURPOSE: To evaluate the ocular findings and the relationship between these findings and the disease severity of patients with Fabry disease (FD) in South-East Anatolia. METHODS: We enrolled the 24 eyes of 24 patients with FD and the disease severity scores were obtained with FD severity scoring system (DS3). The relationship between the presence of any ocular findings and DS3 scores was evaluated. RESULTS: The mean age of the patients was 35.2 ± 8.6 years. The mean DS3 score and α-galactosidase A enzyme activity of the patients was 7.04 ± 3.71 and 1.93 ± 0.84 µmol/l/h, respectively. Of the 24 patients, 20 (83.3%) had cornea verticillate (CV), 18 (75%) had tortuous conjunctival vessels, 15 (62.5%) had tortuous retinal vessels and 3 (12.5%) had lens opacities. The ocular vascular abnormalities were associated with disease severity (p < 0.05); however, the presence of CV did not affect the DS3 scores (p > 0.05). CONCLUSIONS: According to our study, the patients with ocular vascular abnormalities associated with FD had more severe disease than those who did not have an abnormality. CV was the most common ocular finding in FD, but it has no association with disease severity.

Newborn screening for Fabry disease in Oregon: Approaching the iceberg of A143T and variants of uncertain significance.

Fabry disease newborn screening (NBS) has been ongoing in Oregon for over 41 months by first-tier enzyme quantitation and second-tier DNA testing. During that period the majority of abnormal referrals received (34/60) were for the presence of the controversial c.427G > A (p.Ala143Thr) aka A143T and the majority of non-A143T referrals were for other variants of uncertain significance (17/60) resulting in at least 32 infants with an inconclusive case outcome even after clinical evaluation and/or diagnostic testing. To date there has been no significant family history or onset of symptoms in individuals with an inconclusive outcome. Based on our experience, we have developed a framework for approaching A143T and other variants of uncertain clinical significance in an attempt to balance sensitivity with the unnecessary medicalization of healthy infants.

The prevalence of Fabry disease in a statewide chronic kidney disease cohort - Outcomes of the aCQuiRE (Ckd.Qld fabRy Epidemiology) study.

BACKGROUND: Prevalence of Fabry disease amongst Chronic Kidney Disease (CKD) patients on haemodialysis has been shown to be approximately 0.2%. METHODS: We undertook a cross-sectional study employing a cascade screening strategy for Fabry Disease amongst 3000 adult, male and female patients affected by CKD stage 1-5D/T at public, specialty renal practices within participating Queensland Hospital and Health Services from October 2017 to August 2019. A multi-tiered FD screening strategy, utilising a combination of dried blood spot (DBS) enzymatic testing, and if low, then lyso-GB3 testing and DNA sequencing, was used. RESULTS: Mean (SD) age was 64.0 (15.8) years (n = 2992), and 57.9% were male. Eight participants withrew out of the 3000 who consented. Of 2992 screened, 6 (0.20%) received a diagnosis of FD, 2902 (96.99%) did not have FD, and 84 (2.81%) received inconclusive results. Of the patients diagnosed with FD, mean age was 48.5 years; 5 were male (0.29%) and 1 was female (0.08%); 4 were on kidney replacement therapy (2 dialysis and 2 transplant); 3 were new diagnoses. CONCLUSIONS: Estimated overall FD prevalence was 0.20%. Screening of the broader CKD population may be beneficial in identifying cases of FD. TRIAL REGISTRATION: The aCQuiRE Study has been prospectively registered with the Queensland Health Database of Research Activity (DORA, https://dora.health.qld.gov.au ) as pj09946 (Registered 3rd July 2017).

Tenosynovial complications identify TTR cardiac amyloidosis among patients with hypertrophic cardiomyopathy phenotype.

Recent evidence suggests that carpal tunnel syndrome (CTS) and brachial biceps tendon rupture (BBTR) represent red flags for ATTR cardiac amyloidosis (ATTR-CA). The prevalence of upper limb tenosynovial complications in conditions entering differential diagnosis with CA, such as HCM or Anderson-Fabry disease (AFD), and hence their predictive accuracy in this setting, still remains unresolved. OBJECTIVE: To investigate the prevalence of CTS and BBTR in a consecutive cohort of ATTR-CA patients, compared with patients with HCM or AFD and with individuals without cardiac disease history. PARTICIPANTS: Consecutive patients with a diagnosis of ATTR-CA, HCM and AFD were evaluated. A control group of consecutive patients was recruited among subjects hospitalized for noncardiac reasons and no cardiac disease history. The presence of BBTR, CTS or prior surgery related to these conditions was ascertained. RESULTS: 342 patients were prospectively enrolled, including 168 ATTR-CA (141 ATTRwt, 27 ATTRm), 81 with HCM/AFD (N = 72 and 9, respectively) and 93 controls. CTS was present in 75% ATTR-CA patients, compared with 13% and 10% of HCM/AFD and controls (P = 0.0001 for both comparisons). Bilateral CTS was present in 60% of ATTR-CA patients, while it was rare (2%) in the other groups. BBTR was present in 44% of ATTR-CA patients, 8% of controls and 1% in HCM/AFD. CONCLUSIONS: CTS and BBTR are fivefold more prevalent in ATTR-CA patients compared with cardiac patients with other hypertrophic phenotypes. Positive predictive accuracy for ATTR-CA is highest when involvement is bilateral. Upper limb assessment of patients with HCM phenotypes is a simple and effective way to raise suspicion of ATTR-CA.

Screening of Fabry disease in patients with chronic kidney disease in Japan.

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder caused by a deficiency in alfa-galactosidase A (α-Gal A) activity due to mutations in the GLA gene, has a prevalence of 0-1.69% in patients undergoing haemodialysis; however, its prevalence in patients with chronic kidney disease (CKD) Stages 1-5 is unknown. METHODS: Serum α-Gal A activity analysis and direct sequencing of GLA were used to screen for FD in 2122 male patients with CKD, including 1703 patients with CKD Stage 5D and 419 with CKD Stages 1-5. The correlation between serum α-Gal A activity and confounding factors in patients with CKD Stages 1-5 was evaluated. RESULTS: FD prevalence rates in patients with CKD Stage 5D and CKD Stages 1-5 were 0.06% (1/1703) and 0.48% (2/419), respectively. A patient with CKD Stage 5D exhibited a novel GLA mutation, p.Met208Arg, whereas two patients with CKD Stages 1-5 had c.370delG and p.Met296Ile. p. Met208Arg caused moderate structural changes in the molecular surface region near the substituted amino acid residue but did not affect the catalytic residues Asp170 and Asp231 in α-Gal A. Serum α-Gal A activity in patients with CKD Stages 1-5 was inversely correlated with age (P < 0.0001) but directly correlated with estimated glomerular filtration rate (P < 0.0001). CONCLUSIONS: FD prevalence was much higher in male patients with CKD Stages 1-5 than in those with CKD Stage 5D. FD screening in patients with CKD Stages 1-5 may improve patient survival, decreasing the number of patients with CKD Stage 5D.

Identification of patients with Fabry disease using routine pathology results: PATHFINDER (eGFR) study.

AIMS: Lysosomal α-galactosidase A deficiency (Fabry disease (FD)) was considered an X-linked recessive disorder but is now viewed as a variable penetrance dominant trait. The prevalence of FD is 1 in 40 000-117 000 but the ascertainment of late-onset cases and degree of female penetrance makes this unclear. Its prevalence in the general population, especially in patients with abnormal renal function is unclear. This study attempted to identify the prevalence of FD in patients with abnormal renal function results from laboratory databases. METHODS: Electronic laboratory databases were interrogated to identify from clinical biochemistry records patients with a phenotype of reduced estimated glomerular filtration rate categorised by age on one occasion or more over a 3-year time interval. Patients were recalled and a dried blood spot sample was collected for the determination of α-galactosidase A activity by fluorimetric enzyme assay in men and mass spectrometry assays of α-galactosidase A and lyso-globotriaosylceramide (lyso-GL-3) concentrations in women. RESULTS: Samples were obtained from 1084 patients identified with reduced renal function. No cases of FD were identified in 505 men. From 579 women, one subject with reduced α-galactosidase activity (1.5 µmol/L/h) and increased Lyso-GL-3 (5.5 ng/mL) was identified and shown to be heterozygous for a likely FD pathogenic variant (GLA c.898C>T; p.L300F; Leu300Phe). It was later confirmed that she was a relative of a known affected patient. CONCLUSIONS: Pathology databases hold routine information that can be used to identify patients with inherited errors of metabolism. Biochemical screening using reduced eGFR alone has a low yield for unidentified cases of Fabry Disease.

Prevalence of Fabry disease in men with tinnitus and sensorineural hearing loss.

Fabry disease (FD) is a lysosomal storage disorder caused by pathogenic mutations in the alpha-galactosidase A (AGALA) encoding gene region. This rare disease affects several organs including the cochlea-vestibular system. Tinnitus and sensorineural hearing loss (SNHL) are reported among otoneurological symptoms. Early and correct diagnosis of FD is important with a view to available therapy. The aim of the study was to screen for alpha-galactosidase deficiency in men with tinnitus/SNHL. A prospective multicentric study including consecutive patients with SNHL confirmed by tone audiometry or tinnitus evaluated (10/2016-8/2019). The diagnosis of AGALA deficiency was done by dry blood spot method using a threshold of 1.2 µmol/l/h. Only men aged 18-60 were included. 181 patients were subject to evaluation. SNHL was reported in 126 (70%) patients, 50 (28%) patients had unilateral, 76 (42%) patients had bilateral SNHL. Tinnitus was found in 161 (89%) patients, unilateral in 96 (53%) and bilateral in 65 (36%) patients. Suspected FD was not detected in any patient; alpha-galactosidase The AGALA values ranged 1.5-8.8 µmol/l/h, an average of 3.4 µmol/l/h. None of the 181 patients participating in the study had AGALA levels below the threshold 1.2 µmol/l/h. The occurrence of tinnitus and sensorineural hearing loss in men appears to be an irrelevant clinical sign for FD systematic screening.

The Fabry disease-causing mutation, GLA IVS4+919G>A, originated in Mainland China more than 800 years ago.

The Fabry disease-causing mutation, the GLA IVS4+919G>A (designated GLA IVS4), is very prevalent in patients with hypertrophic cardiomyopathy in Taiwan. This X-linked mutation has also been found in patients in Kyushu, Japan and Southeast Asia. To investigate the age and the possible ancestral origin of this mutation, a total of 33 male patients with the GLA IVS4+919G>A mutation, born in Taiwan, Japan, Singapore, Malaysia, Vietnam, and the Fujian and Guangdong provinces of China, were studied. Peripheral bloods were collected, and the Ilumina Infinium CoreExome-24 microarray was used for dense genotyping. A mutation-carrying haplotype was discovered which was shared by all 33 patients. This haplotype does not exist in 15 healthy persons without the mutation. Rather, a wide diversity of haplotypes was found in the vicinity of the mutation site, supporting the existence of a single founder of the GLA IVS4 mutation. The age of the founder mutation was estimated by the lengths of the mutation-carrying haplotypes based on the linkage-disequilibrium decay theory. The first, second, and third quartile of the age estimates are 800.7, 922.6, and 1068.4 years, respectively. We concluded that the GLA IVS4+919G>A mutation originated from a single mutational event that occurred in a Chinese chromosome more than 800 years ago.

Quality of life and psychological functioning of pediatric and young adult patients with Gaucher disease, type 1.

This study examined the health-related quality of life (HRQoL) and psychological functioning of children and young adults with Gaucher disease, type 1 (GD1). Thirty-two (17 pediatric, 15 young adult) patients with GD1 and one parent completed age-appropriate assessments of HRQoL, emotional, and behavioral health. The HRQoL of children with GD1 was compared with a healthy sample and to children diagnosed with Fabry disease (FD; another lysosomal storage disease), while young adults were compared to a healthy sample and to patients with self-reported chronic illnesses. Children with GD1 reported significantly lower HRQoL across all domains relative to healthy counterparts yet comparable HRQoL compared to children with FD. Young adults reported mildly lower physical functioning than healthy peers, but no differences in HRQoL relative to the chronic illness sample. Parent-reported symptom severity was associated with poorer HRQOL in children but not young adults. Few group differences in psychological functioning were observed, except young children showed more school problems than the normative average and there was a trend toward internalizing symptoms. Overall, results consistently identified younger patients with GD1 as more affected than older patients in HRQoL and psychological domains. Implementation of psychosocial interventions may be particularly beneficial during early childhood.