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.

Fabry disease defined: baseline clinical manifestations of 366 patients in the Fabry Outcome Survey

BACKGROUND

Fabry disease is a rare X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the substrate globotriaosylceramide in cells throughout the body leads to major organ failure and premature death. In response to the recent introduction of enzyme replacement therapy, the Fabry Outcome Survey (FOS) was established to pool data from European clinics on the natural history of this little-known disease and to monitor the long-term efficacy and safety of treatment. This paper presents the first analysis of the FOS database and provides essential baseline data against which the effects of enzyme replacement can be measured.

DESIGN

Baseline data from a cohort of 366 patients from 11 European countries were analysed in terms of demography and clinical manifestations of Fabry disease.

RESULTS

Misdiagnosis of Fabry disease is common, and the mean delay from onset of symptoms to correct diagnosis was 13.7 and 16.3 years in males and females, respectively. Although previously thought to have serious manifestations only in hemizygous men, the FOS database has confirmed that females heterozygous for Fabry disease are similarly affected. Furthermore, signs and symptoms of Fabry disease may be present from early childhood.

CONCLUSIONS

With the advent of enzyme replacement therapy, it is important that general practitioners and physicians in a range of specialties recognize the signs and symptoms of Fabry disease so that effective treatment can be given. Baseline data from FOS demonstrate that enzyme replacement therapy should not be restricted to hemizygous men, but should be considered for both heterozygous females and children.

Fabry's disease

Fabry's disease is an X-linked lysosomal storage disorder caused by abnormalities in the GLA gene, which leads to a deficiency in alpha-galactosidase A. The consequent abnormal accumulation of glycosphingolipids results in several clinical signs and symptoms and substantial morbidity and mortality. This review covers all basic aspects of the disease such as epidemiology, pathophysiology, clinical presentation by systems, diagnosis, management, prevention, and repercussions on quality of life. With the development of enzyme replacement therapy in the past few years, early initiation of treatment is key for improvement in major affected organs with decreased cardiac mass and stabilisation of kidney function, and improvement in neuropathic pain, sweating, gastrointestinal symptoms, hearing loss, and pulmonary symptoms. However, treatment of individual symptoms in addition to enzyme replacement therapy seems to be needed for many patients, especially those who have had some degree of organ dysfunction. Additional data are needed to document long-term treatment outcomes.

Prevalence of Anderson-Fabry disease in male patients with late onset hypertrophic cardiomyopathy

BACKGROUND

Although studies have suggested that "late-onset" hypertrophic cardiomyopathy (HCM) may be caused by sarcomeric protein gene mutations, the cause of HCM in the majority of patients is unknown. This study determined the prevalence of a potentially treatable cause of hypertrophy, Anderson-Fabry disease, in a HCM referral population.

METHODS AND RESULTS

Plasma alpha-galactosidase A (alpha-Gal) was measured in 79 men with HCM who were diagnosed at > or =40 years of age (52.9+/-7.7 years; range, 40-71 years) and in 74 men who were diagnosed at <40 years (25.9+/-9.2 years; range, 8-39 years). Five patients (6.3%) with late-onset disease and 1 patient (1.4%) diagnosed at <40 years had low alpha-Gal activity. Of these 6 patients, 3 had angina, 4 were in New York Heart Association class 2, 5 had palpitations, and 2 had a history of syncope. Hypertrophy was concentric in 5 patients and asymmetric in 1 patient. One patient had left ventricular outflow tract obstruction. All patients with low alpha-Gal activity had alpha-Gal gene mutations.

CONCLUSION

Anderson-Fabry disease should be considered in all cases of unexplained hypertrophy. Its recognition is important given the advent of specific replacement enzyme therapy.

Fabry disease: detection of undiagnosed hemodialysis patients and identification of a "renal variant" phenotype

BACKGROUND

Fabry disease is an X-linked recessive lysosomal storage disease resulting from deficient alpha-galactosidase A (alpha-Gal A) activity. Renal failure is a major debilitating complication in classically affected males. To determine if this disorder is underdiagnosed in patients with end-stage renal disease (ESRD), the frequency of unrecognized males with Fabry disease on chronic hemodialysis was determined.

METHODS

Plasma alpha-Gal A activity was measured in 514 consecutive males with ESRD on hemodialysis. Patients with low alpha-Gal A activity were evaluated clinically and their alpha-Gal A mutations were determined.

RESULTS

Six (1.2%) of 514 hemodialysis patients had low plasma alpha-Gal A activities and a previously identified (E66Q, A97V, M296I) or novel (G373D) missense mutation. At ages 30 to 68 years, five patients lacked the classic manifestations of angiokeratoma, acroparesthesias, hypohidrosis, and ocular opacities, while the sixth lacked angiokeratoma and ocular changes. Five had left ventricular hypertrophy (LVH).

CONCLUSION

The clinical spectrum of Fabry disease includes a "renal variant" phenotype in patients without classic symptoms who develop ESRD. Affected males undergoing hemodialysis or renal transplantation can be readily diagnosed by plasma alpha-Gal A assays. These patients and their family members may benefit from enzyme replacement therapy for the later, life-threatening cardiovascular and cerebrovascular complications of Fabry disease.

Prevalence of Fabry disease in patients with cryptogenic stroke: a prospective study

BACKGROUND

Strokes are an important cause of morbidity and mortality in young adults. However, in most cases the cause of the stroke remains unclear. Anderson-Fabry disease is an X-linked recessive lysosomal storage disease resulting from deficient alpha-galactosidase and causes an endothelial vasculopathy followed by cerebral ischaemia. To determine the importance of Fabry disease in young people with stroke, we measured the frequency of unrecognised Fabry disease in a cohort of acute stroke patients.

METHODS

Between February, 2001, and December, 2004, 721 German adults aged 18 to 55 years suffering from acute cryptogenic stroke were screened for Fabry disease. The plasma alpha-galactosidase activity in men was measured followed by sequencing of the entire alpha-GAL gene in those with low enzyme activity. By contrast, the entire alpha-GAL gene was genetically screened for mutations in women even if enzyme activity was normal.

FINDINGS

21 of 432 (4.9%) male stroke patients and seven of 289 (2.4%) women had a biologically significant mutation within the alpha-GAL gene. The mean age at onset of symptomatic cerebrovascular disease was 38.4 years (SD 13.0) in the male stroke patients and 40.3 years (13.1) in the female group. The higher frequency of infarctions in the vertebrobasilar area correlated with more pronounced changes in the vertebrobasilar vessels like dolichoectatic pathology (42.9%vs 6.8%).

INTERPRETATION

We have shown a high frequency of Fabry disease in a cohort of patients with cryptogenic stroke, which corresponds to about 1.2% in young stroke patients. Fabry disease must be considered in all cases of unexplained stroke in young patients, especially in those with the combination of infarction in the vertebrobasilar artery system and proteinuria.

Newborn screening for Fabry disease in Taiwan reveals a high incidence of the later-onset GLA mutation c.936+919G>A (IVS4+919G>A)

Fabry disease (alpha-galactosidase A (alpha-Gal A, GLA) deficiency) is a panethnic inborn error of glycosphingolipid metabolism. Because optimal therapeutic outcomes depend on early intervention, a pilot program was designed to assess newborn screening for this disease in 171,977 consecutive Taiwanese newborns by measuring their dry blood spot (DBS) alpha-Gal A activities and beta-galactosidase/alpha-Gal A ratios. Of the 90,288 male screenees, 638 (0.7%) had DBS alpha-Gal A activity <30% of normal mean and/or activity ratios >10. A second DBS assay reduced these to 91 (0.1%). Of these, 11 (including twins) had <5% (Group-A), 64 had 5-30% (Group-B), and 11 had >30% (Group-C) of mean normal leukocyte alpha-Gal A activity. All 11 Group-A, 61 Group-B, and 1 Group-C males had GLA gene mutations. Surprisingly, 86% had the later-onset cryptic splice mutation c.936+919G>A (also called IVS4+919G>A). In contrast, screening 81,689 females detected two heterozygotes. The novel mutations were expressed in vitro, predicting their classical or later-onset phenotypes. Newborn screening identified a surprisingly high frequency of Taiwanese males with Fabry disease (approximately 1 in 1,250), 86% having the IVS4+919G>A mutation previously found in later-onset cardiac phenotype patients. Further studies of the IVS4 later-onset phenotype will determine its natural history and optimal timing for therapeutic intervention.

Fabry disease: baseline medical characteristics of a cohort of 1765 males and females in the Fabry Registry

The Fabry Registry is a global observational research platform established to define outcome data on the natural and treated course of this rare disorder. Participating physicians submit structured longitudinal data to a centralized, confidential database. This report describes the baseline demographic and clinical characteristics of the first 1765 patients (54% males (16% aged < 20 years) and 46% females (13% < 20 years)) enrolled in the Fabry Registry. The median ages at symptom onset and diagnosis were 9 and 23 years (males) and 13 and 32 years (females), respectively, indicating diagnostic delays in both sexes. Frequent presenting symptoms in males included neurological pain (62%), skin signs (31%), gastroenterological symptoms (19%), renal signs (unspecified) (17%), and ophthalmological signs (11%). First symptoms in females included neurological pain (41%), gastroenterological symptoms (13%), ophthalmological (12%), and skin signs (12%). For those patients reporting renal progression, the median age at occurrence was 38 years for both sexes, but onset of cerebrovascular and cardiovascular events was later in females (median 43 and 47 years, respectively) than in males (38 and 41 years, respectively). This paper demonstrates that in spite of the considerable burden of disease in both sexes that begins to manifest in childhood or adolescence, the recognition of the underlying diagnosis is delayed by 14 years in males and 19 years in females. The Fabry Registry provides data that can increase awareness of common symptoms in all age groups, as well as insight into treated and untreated disease course, leading to improved recognition and earlier treatment, and possibly to improved outcomes for affected individuals.

Natural history of Fabry disease in females in the Fabry Outcome Survey

BACKGROUND

Fabry disease is a rare X linked lysosomal storage disorder resulting from deficiency of alpha-galactosidase A activity. Although the severity of clinical features in male patients is well described, only recently have studies reported the high prevalence of disabling clinical features in heterozygous females.

AIMS

This study sets out to examine the clinical features and natural history of Fabry disease in further detail in a large group of female patients.

METHODS

Data were obtained from 303 females enrolled in the Fabry Outcome Survey. Pain was assessed using the Brief Pain Inventory, and health related quality of life (HRQoL) was assessed using the European Quality of Life Questionnaire. A modified version of the Mainz Severity Score Index was also applied. Data on left ventricular mass (LVM) index, mean ventricular wall thickness, and glomerular filtration rate (GFR) were used to assess cardiac and renal involvement.

RESULTS

The most commonly reported clinical features in females were neurological (77%) and cardiac (59%). A history of renal involvement was recorded in 40% of cases. Neurological features were the earliest to develop (mean age: 16 years), whereas cardiac (mean age: 33.5 years) and renal (mean age: 37.3 years) features developed later. LVM index increased exponentially with age. In addition, age was negatively correlated with estimated GFR and HRQoL.

CONCLUSIONS

Females with Fabry disease report important age related clinical features and clinical investigation demonstrates evidence of disease progression. This study highlights the importance of careful and longitudinal assessment of female heterozygote patients with Fabry disease.

Prevalence of Fabry disease in female patients with late-onset hypertrophic cardiomyopathy

BACKGROUND

Fabry disease (FD) has been recognized as the cause of left ventricular hypertrophy in 6% of men with late-onset hypertrophic cardiomyopathy (HCM). Although FD is considered a recessive X-linked disorder, affected women are increasingly reported. The aim of our study was to determine the prevalence of FD in female patients with HCM.

METHODS AND RESULTS

Thirty-four consecutive women (mean age, 50+/-13.6 years) who received an ECG and echocardiographic diagnosis of HCM were submitted to an invasive cardiac study that included a biventricular endomyocardial biopsy. Tissue samples were analyzed for histology and electron microscopy. Peripheral blood activity of alpha-galactosidase (alpha-Gal) A was assessed in all patients. None of them had a family history of FD. Histology and electron microscopy showed in 4 patients (12%; mean age, 51.5+/-3.9 years) the presence of cell vacuoles characterized by the accumulation of glycolipid material organized in concentric lamellar structures, diagnostic for FD. In the remaining patients, histology was consistent with HCM. In all the female carriers, the heart was the only organ clinically involved in the disease, showing concentric hypertrophy in 2 patients, asymmetric hypertrophy in 1, and apical hypertrophy in 1. The alpha-Gal A enzymatic activity was 44+/-14% of control values. Genetic analysis showed the presence of alpha-Gal A gene mutation in all 4 cases.

CONCLUSIONS

FD may account for up to 12% of females with late-onset HCM. Those heterozygous for FD with left ventricular hypertrophy are potential candidates for enzyme enhancement/replacement therapy.

The early clinical phenotype of Fabry disease: a study on 35 European children and adolescents

Fabry disease (FD) is a debilitating progressive multisystem X-linked lysosomal storage disorder. It was generally believed that the disease affects only adult males. Through systematic pedigree analysis, we identified 35 paediatric FD patients (age 1 to 21 years, mean 12.6 years) in 25 families. Predominant signs in this cohort were: acroparesthesia, hypohidrosis, and cornea verticillata. Neurological and psychological changes, such as tinnitus, recurrent vertigo, headache, diminished level of activity, fatigue, and depression were often observed. Angiokeratoma and gastrointestinal symptoms were frequent. Some patients also showed cardiac abnormalities. Six children and adolescents (three males and three females) over 14 years of age had renal involvement (all with proteinuria, one male had a decreased creatinine clearance of 62 ml/min). No males, but three females (1.5, 4 and 9 years of age), were free of signs and symptoms. Males (n=15, age 1 to 21 years, mean 12.4 years) and females (n=20, age 1.5 to 20 years, mean 12.7 years) showed comparable disease severity. However, the clinical courses demonstrated a wide intra- and interfamilial variability and tended to be more heterogeneous in the girls. Female patients are frequently affected at an early age, not much differently than males. They should be carefully examined because most carriers are symptomatic.

CONCLUSION

Fabry disease usually becomes clinically manifest in childhood. Renal involvement can begin in adolescence. The diagnosis is made following a high level of suspicion or systematic pedigree analysis. It is crucial for paediatric Fabry disease patients to have early access to optimal supportive symptomatic management. Enzyme replacement therapy has shown promising effectiveness in adults. Considering its widespread therapeutic and potential preventive benefits, enzyme replacement therapy should be initiated at an early stage, prior to the onset of irreversible complications.

Relationship between X-inactivation and clinical involvement in Fabry heterozygotes. Eleven novel mutations in the alpha-galactosidase A gene in the Czech and Slovak population

We have identified 21 different alpha-galactosidase A gene (GLA) mutations in 22 unrelated Czech and Slovak families with Fabry disease. Eleven of these mutations were novel (point mutations D93N, A135V, D155H, G171R, Q280K, G360S, Q330X, splicing errors c.194ins14, c.801ins36 and deletions c.674_732del59, g.3405_6021del2617). Genotyping of family members for family-specific mutations revealed 55 heterozygotes that manifested clinical symptoms of different severity. To examine the contribution of X-inactivation skewing to disease manifestation in Fabry heterozygotes, we have adopted the Mainz severity scoring scheme and compared the score values with the X-inactivation status in 39 carriers in an age-dependent manner. The age-score trendline of Fabry females who had a predominantly inactivated X-chromosome bearing a wild-type GLA allele (10 of 38 females) was markedly steeper than in the rest of the cohort. One female carrier with an inactivated mutated allele had a low score value when compared to the other heterozygotes of the same age. These data suggest that X-inactivation is indeed a major factor determining the severity of clinical involvement in Fabry heterozygotes. There was a statistically significant difference between the severity score values of heterozygotes with random and non-random X-chromosome inactivation at the 5% level of significance. Further studies will show if the degree of the wildtype allele inactivation will be useful as a predictive marker of severity of phenotype in Fabry heterozygotes. Although the correlation between X-inactivation skewing and presentation of the disease in Fabry heterozygotes has previously been suggested in the literature, this report is among the first attempts to examine this relationship systematically.

Gastrointestinal symptoms in 342 patients with Fabry disease: prevalence and response to enzyme replacement therapy

BACKGROUND & AIMS

Fabry disease is an X-linked deficiency of alpha-galactosidase A, resulting in lysosomal deposition of globotriaosylceramide in nearly all tissues. The disease frequently causes diarrhea and abdominal pain, which are assumed to arise from malfunction of enteric neurons and which mimic diarrhea-predominant irritable bowel syndrome (IBS). There are limited data about the prevalence and nature of gastrointestinal symptoms in patients with Fabry disease and the response to enzyme replacement therapy (ERT) in large cohorts. The aims of this study were to evaluate the nature and prevalence of gastrointestinal symptoms and their impact on health-related quality of life (HRQoL) in patients with Fabry disease and to analyze changes after 12 and 24 months of treatment with agalsidase alfa.

METHODS

Information about gastrointestinal symptoms was obtained from regular interviews before and during the time of ERT. Data on HRQoL were collected by using the EQ-5D questionnaire.

RESULTS

The overall prevalence of gastrointestinal symptoms was 52%, with abdominal pain and diarrhea being most frequent. Female patients were more frequently affected than male patients, and there was a high prevalence in children (abdominal pain, 49.3%; diarrhea 25.4%). ERT with agalsidase alfa reduced the prevalence of abdominal pain, with a statistically significant decrease in male patients and in children after 12 months of treatment.

CONCLUSIONS

The gastrointestinal symptomatology of Fabry disease is very similar to diarrhea-predominant IBS; however, pathophysiologic similarities remain to be elucidated. ERT reduced the prevalence of gastrointestinal symptoms in Fabry disease, particularly in children and male patients.

Ocular manifestations of Fabry's disease: data from the Fabry Outcome Survey

BACKGROUND

Fabry's disease is an X-linked lysosomal storage disorder characterised by deficient activity of the enzyme alpha-galactosidase A.

AIM

To study eye abnormalities in patients with Fabry's disease in the Fabry Outcome Survey (FOS).

METHODS

This is the largest study of ocular manifestations in patients with Fabry's disease. In all, 173 of the 688 patients enrolled in FOS underwent a detailed ophthalmic examination, with a special focus on abnormalities of the cornea, lens, conjunctival and retinal vessels.

RESULTS

Cornea verticillata was reported in 76.9% of females and 73.1% of males; vessel tortuosity was observed in 21.9% of females and in 48.7% of males. Fabry cataract was recorded in 9.8% of females and in 23.1% of males. Cornea verticillata was therefore the most frequently reported ophthalmic abnormality in Fabry's disease in both hemizygotic males and heterozygotic females. Tortuous conjunctival and retinal vessels and Fabry cataract were more frequently found in males than in females. Vessel tortuosity was more frequently observed in patients with a higher severity score and greater impairment of renal and cardiac function, suggesting that it may be associated with a more severe disease. The youngest patient with ocular changes was 3 years old. The prevalence of tortuous vessels in males increased with age.

CONCLUSION

The presence of cornea verticillata is a useful aid in the diagnosis of Fabry's disease, as it is often present at the time of diagnosis. Vessel tortuosity may have some predictive value for systemic involvement.

Fabry disease and the skin: data from FOS, the Fabry outcome survey

BACKGROUND

Fabry disease (also known as Anderson-Fabry disease) is a rare, X-linked lysosomal storage disorder that is characterized by accumulation of globotriaosylceramide throughout a range of tissues in the body.

OBJECTIVES

To ascertain the prevalence and nature of cutaneous manifestations in patients with Fabry disease and to relate these to the severity of systemic manifestations of the disease.

METHODS

We have documented the dermatological features of this disease with reference to data from 714 patients (345 males, 369 females) registered on the Fabry Outcome Survey (FOS), a multicentre European database.

RESULTS

We confirm that the commonest disease manifestation is angiokeratoma. Overall, 78% of males and 50% of females had one or more dermatological abnormality, the commonest being angiokeratoma (66% males, 36% females), hypohidrosis (53% males, 28% females), telangiectasia (23% males, 9% females) and lymphoedema (16% males, 6% females). We demonstrate for the first time that the presence of cutaneous vascular lesions correlates with the severity of the systemic manifestations of the disease (pain, renal failure, cardiac disease, premature cerebrovascular disease) as assessed by a severity scoring system. Although the condition is X linked, there is a surprisingly high prevalence of abnormalities in females.

CONCLUSIONS

The FOS database is a useful epidemiological tool in establishing the variety and relevance of cutaneous manifestations in Fabry disease. The present study confirms that the presence of dermatological manifestations appears to be a marker of greater severity of systemic disease, which emphasizes the importance of the dermatological assessment of these patients.

Depression in adults with Fabry disease: a common and under-diagnosed problem

BACKGROUND

Anderson-Fabry disease (AFD), an X-linked lysosomal storage disorder, leads to multi-organ dysfunction and premature mortality. Depression in adults with AFD has been reported, but no large study has been done. We have examined the adult Fabry population in the United Kingdom to describe the prevalence, associated factors and frequency of diagnosis of depression.

METHODS

Postal questionnaires were sent from four adult clinics to 296 AFD patients. A response rate of 62% (n = 184; 74 male, 110 female) formed the data set. Questionnaires collected demographic and Fabry-specific information. Depression status was assessed using the Centre for Epidemiological Studies depression scale (CES-D).

RESULTS

Responders were aged between 18 and 76 years (mean 44). The prevalence of depression was 46%, of which 28% were consistent with 'severe clinical depression'. Unlike the normal population, males with AFD report a higher prevalence of severe depression than females (36% males; 22% females). Interference of AFD symptoms with individuals' lives (particularly acroparaesthesiae or anhidrosis) showed the largest odds of association with depression. Relationship and financial status proved strong predictors of depression: 88% of those with mild-moderate depression and 72% with severe depression were undiagnosed.

CONCLUSION

Depression is common and under-diagnosed in AFD. Proper assessment of and treatment for depression could improve the quality of life of these patients.

Report on management of renale failure in Europe, XXVI, 1995. Rare diseases in renal replacement therapy in the ERA-EDTA Registry

The proportion of centres returning the ERA-EDTA Registry questionnaires has decreased considerably in recent years. Demographic information, based on the response rate of centres in 1994 (44%), does not allow reasonable projections for management of renal failure in Europe. To encourage the participation of non-responding centres, the timing was right to show the powerful impact of the ERA-EDTA Registry as a supra-national registry, by studying patients in renal replacement therapy (RRT) suffering from rare diseases. Four such diseases, Fabry's disease, nephropathy due to cyclosporin (CsA), nephropathy due to cisplatin and scleroderma, were studied using the records of 440665 patients on file up to 31 December 1993. There were 83 patients with Fabry's disease (0.0188%), 85 patients with CsA nephropathy (0.0193%), 120 patients with cisplatin nephropathy (0.0272%) and 625 patients with scleroderma (0.142%). Scleroderma was introduced as a primary renal disease (PRD) in the ERA-EDTA Registry in 1977. Seven patients were accepted for RRT in that year, whereas the number increased to over 50 new patients per year after 1986. More than half of the patients were aged over 55 years, and 68% of them were women. Survival rate of dialysis patients suffering from scleroderma was 22% at 5 years, compared to 51% in patients with standard primary renal diseases. The main causes of death were cardiovascular complications (41%), cachexia (15%) and infection (10%). Survival of first graft in a small number of 28 patients was 44% at 3 years, compared to 60% in standard PRD. Patient survival after first transplant, however, was higher by 32% at 3 years compared to that of dialysis patients. Cisplatin nephropathy was introduced as a PRD in the ERA-EDTA Registry in 1985, and since then six to 19 new patients have been accepted for RRT each year. The main reason for undergoing cisplatin treatment was ovarian (32%) and testicular cancer (21%), and the mean interval from treatment to RRT was 21.5 months, ranging widely from 0.1 to 131 months. Patient survival on dialysis was 22% at 5 years, compared to 51% in patients with standard PRD. Malignancy and cachexia accounted for over 60% of the total number of deaths. CsA nephropathy was introduced as a PRD in the ERA-EDTA Registry in 1985 and, despite its rarity, is of particular interest as a new iatrogenic entity resulting from CsA administration, mainly in solid organ transplantation. In 1985, two new patients commenced RRT in Europe, and the number increased to 59 in 1991-93. The main reason for undergoing CsA treatment was heart (68%) and liver transplant (22%), and the mean interval from treatment to RRT was 50.2 months, ranging from 5 to 90 months. Patient survival on dialysis was 46% at 4 years, compared to 58% in patients with standard primary nephropathies. Cardiovascular causes (48%) and infection (17%) were the main causes of death. Fabry's disease was introduced as a PRD in the ERA-EDTA Registry in 1985, and since the four to 13 new patients per year have commenced RRT in Europe. It is a sex-linked recessive disorder primarily affecting males (87%), and the mean age at start of RRT was 38 years. Proteinuria, skin lesions and painful paresthesiae were the most common presenting symptoms, and over 70% of the patients were hypertensive and had significant cardiovascular problems at RRT. Patient survival on dialysis was 41% at 5 years, compared to 68% in patients with standard primary nephropathies. Cardiovascular complications (48%) and cachexia (17%) were the main causes of death. Graft survival at 3 years in 33 patients was not inferior to that of patients with standard nephropathies (72% vs 69%), and patient survival after transplantation was comparable to that of patients under 55 years of age with standard PRD. (ABSTRACT TRUNCATED)

Ophthalmological manifestations of Fabry disease: a survey of patients at the Royal Melbourne Fabry Disease Treatment Centre

BACKGROUND

Fabry disease is a rare X-linked inborn error of glycosphingolipid metabolism. The aim of this study was to document the ophthalmological manifestations of patients attending the Royal Melbourne Hospital Fabry disease treatment centre.

METHODS

Patients at the treatment centre had full ophthalmological examination performed. This included best corrected visual acuity, ocular motility examination and examination of the adnexae. Patients also underwent slit-lamp examination looking for the presence of features of Fabry disease, particularly examining the bulbar conjunctiva, cornea, lens and fundus.

RESULTS

Thirty-four hemizygous male and 32 heterozygous female patients were recruited. The mean age of the hemizygous male patients was 37.7 years (range 18-57 years). The mean age of the heterozygous female patients was 34.6 years (range 1-78 years). Visual acuity was not affected. 97.1% of the hemizygotes and 78.1% of the heterozygotes had vascular abnormalities of the bulbar conjunctiva. Cornea verticillata was noted in 94.1% of the hemizygotes and 71.9% of the heterozygotes. 41.2% of the hemizygotes and 9.4% of the heterozygotes had anterior cataract formation. Posterior lens opacities were observed in 11.8% of the hemizygotes and none of the heterozygotes. Retinal vascular tortuosity was observed in 76.5% of the hemizygotes and 18.8% of the heterozygotes.

CONCLUSION

Conjunctival vascular tortuosity was the most common manifestation in this series. Conjunctival and retinal vessel tortuosity, and corneal verticillata are frequently observed in Fabry disease. The incidence of lenticular changes is not consistently reported, but in this series and many others, it is much less common than that of corneal, conjunctival and retinal changes.

Neurological complications of Anderson-Fabry disease

Characteristic clinical manifestations of AFD such as acroparesthesias, angiokeratoma, corneal opacity, hypo/ and anhidrosis, gastrointestinal symptoms, renal and cardiac dysfunctions can occur in male and female patients, although heterozygous females with AFD usually seem to be less severely affected. The most prominent CNS manifestations consist of cerebrovascular events such as transient ischaemic attacks (TIAs) and (recurrent) strokes. For the most part, CNS complications in AFD have been attributed to cerebral vasculopathy, including anatomical abnormalities. The natural history of Fabry patients includes transitory cerebral ischaemia and strokes, even in very young persons of both genders. The mechanism is partly due to vascular endothelial accumulation of Gb-3. White matter lesions (WML) on occur MRI. Both males and females can be safely treated with enzyme replacement; and thus screening for Fabry disease of young stroke populations should be considered. There are, however, no hard data of treatment effect on mortality and morbidity. Stroke in Anderson-Fabry disease study of 721 patients with cryptogenic stroke, aged 18-55 years, showed a high prevalence of Fabry disease in this group: 5% (21/432) of men and 3% (7/289) of women. Combining results of both sexes showed that 4% of young patients with stroke of previously unknown cause had Fabry disease, corresponding to about 1-2% of the general population of young stroke patients. Cerebral micro- and macro-vasculopathy have been described in Fabry disease. Neuronal globotriaosylceramide accumulation in selective cortical and brain stem areas including the hippocampus has been reported by autopsy studies in FD, but clinical surrogates as well as the clinical relevance of these findings have not been investigated so far. Another Neurologic hallmark of Fabry disease (FD) includes small fiber neuropathy as well as cerebral micro- and macroangiopathy with premature stroke. Cranial MRI shows progressive white matter lesions (WML) at an early age, increased signal intensity in the pulvinar, and tortuosity and dilatation of the larger vessels. Conventional MRI shows a progressive load of white matter lesions (WMLs) due to cerebral vasculopathy in the course of FD. Another study has been conducted to quantify brain structural changes in clinically affected male and female patients with FD. The peripheral neuropathy in Fabry disease manifests as neuropathic pain, reduced cold and warm sensation and possibly gastrointestinal disturbances. Patients with Fabry disease begin having pain towards the end of the first decade of life or during puberty. Children as young as 6 years of age have complained of pain often associated with febrile illnesses with reduced heat and exercise tolerance. The patients describe the pain as burning that is often associated with deep ache or paresthesiae. Some patients also have joint pain. A high proportion of patients with Fabry disease is at increased risk of developing neuropsychiatric symptoms, such as depression and neuropsychological deficits. Due to both somatic and psychological impairment, health-related quality of life (QoL) is considerably reduced in patients with Fabry disease. Targeted screening for Fabry disease among young individuals with stroke seems to disclose unrecognized cases and may therefore very well be recommended as routine in the future. Furthermore, ischemic stroke is related to inflammation and arterial stiffness and no study had addressed this relationship in patients with AF disease and cerebrovascular disease, so this topic could represent a possible future research line.

Molecular analysis in Fabry disease in Spain: fifteen novel GLA mutations and identification of a homozygous female

Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from mutations in the alpha-galactosidase A gene (GLA). Here we report molecular studies in 22 unrelated Spanish patients with Fabry disease ( 20 males and two females). Fifteen novel mutations were identified. In addition 7 previously described mutations and two previously reported polymorphisms were detected. The 15 novel mutations comprise: eight missense E48K (c.142G>A), W81S (c.242G>C), D170H (c.508G>C), W226C (c.678G>T), Q279R (c.836A>G), C382Y (c.1145G>A), I407K (c.1220T>A), L414S (c.1241T>C); one nonsense W95X (c.284G>A); one insertion Y216fsX15 (c.646_647insT); two small deletions G346fsX1 (c.1037delG), K426fsX23 (c.1277_1278delAA); one gross deletion comprising exons 5, 6, 7; one complex mutation (insertion and deletion) A368fsX24 (c.1102delGinsTTATAC), and one splice-site mutation IVS4+1G>A (c.639+1G>A). One of the females was found homozygous for Q279R mutation and she presented with the classic phenotype since the age of 8 years, this case extending into women the severe phenotype observed in classically affected males. Mutation analysis provided precise identification for 30 heterozygotes among female relatives and detection of a de novo mutation. The molecular studies on Spanish Fabry patients here reported further contribute to the identification of new mutations in this disease, and allow reliable detection of heterozygotes which has consequences for genetic counselling and for treatment.

The alpha-galactosidase A p.Arg118Cys variant does not cause a Fabry disease phenotype: data from individual patients and family studies

Lysosomal α-galactosidase A (α-Gal) is the enzyme deficient in Fabry disease (FD), an X-linked glycosphingolipidosis caused by pathogenic mutations affecting the GLA gene. The early-onset, multi-systemic FD classical phenotype is associated with absent or severe enzyme deficiency, as measured by in vitro assays, but patients with higher levels of residual α-Gal activity may have later-onset, more organ-restricted clinical presentations. A change in the codon 118 of the wild-type α-Gal sequence, replacing basic arginine by a potentially sulfhydryl-binding cysteine residue - GLA p.(Arg118Cys) -, has been recurrently described in large FD screening studies of high-risk patients. Although the Cys118 allele is associated with high residual α-Gal activity in vitro, it has been classified as a pathogenic mutation, mainly on the basis of theoretical arguments about the chemistry of the cysteine residue. However its pathogenicity has never been convincingly demonstrated by pathology criteria. We reviewed the clinical, biochemical and histopathology data obtained from 22 individuals of Portuguese and Spanish ancestry carrying the Cys118 allele, including 3 homozygous females. Cases were identified either on the differential diagnosis of possible FD manifestations and on case-finding studies (n=11; 4 males), or on unbiased cascade screening of probands' close relatives (n=11; 3 males). Overall, those data strongly suggest that the GLA p.(Arg118Cys) variant does not segregate with FD clinical phenotypes in a Mendelian fashion, but might be a modulator of the multifactorial risk of cerebrovascular disease. The Cys118 allelic frequency in healthy Portuguese adults (n=696) has been estimated as 0.001, therefore not qualifying for "rare" condition.

Middelheim Fabry Study (MiFaS): a retrospective Belgian study on the prevalence of Fabry disease in young patients with cryptogenic stroke

OBJECTIVE

To assess the prevalence of Fabry disease in young patients with cryptogenic stroke.

PATIENTS AND METHODS

We retrospectively assessed the prevalence of Fabry disease in patients aged 16-60 years that were admitted to ZNA Middelheim Hospital from January 1, 2000 to December 31, 2004 for cryptogenic stroke. We screened for Fabry disease by measurement of alpha-galactosidase A and beta-glucuronidase activity on blood spot. In all patients with abnormal enzymatic activity and in all female patients with low normal values, genetic sequencing of the alpha-GAL-gene was performed.

RESULTS

In a population of 103 young patients with cryptogenic stroke that met the in- and exclusion criteria, we were unable to identify any patient with Fabry disease.

CONCLUSION

Based on the results of alpha-galactosidase A and beta-glucuronidase activity, genetic sequencing and the low prevalence of clinical signs and symptoms of Fabry disease in this population, we believe that the true prevalence of Fabry disease in patients with cryptogenic stroke may be less than currently accepted in literature.