Disease manifestations and X inactivation in heterozygous females with Fabry disease

Neonatal screening for lysosomal storage disorders: feasibility and incidence from a nationwide study in Austria

BACKGROUND

The interest in neonatal screening for lysosomal storage disorders has increased substantially because of newly developed enzyme replacement therapies, the need for early diagnosis, and technical advances. We tested for Gaucher's disease, Pompe's disease, Fabry's disease, and Niemann-Pick disease types A and B in an anonymous prospective nationwide screening study that included genetic mutation analysis to assess the practicality and appropriateness of including these disorders in neonatal screening panels.

METHODS

Specimens from dried blood spots of 34,736 newborn babies were collected consecutively from January, 2010 to July, 2010, as part of the national routine Austrian newborn screening programme. Anonymised samples were analysed for enzyme activities of acid β-glucocerebrosidase, α-galactosidase, α-glucosidase, and acid sphingomyelinase by electrospray ionisation tandem mass spectrometry. Genetic mutation analyses were done in samples with suspected enzyme deficiency.

FINDINGS

All 34,736 samples were analysed successfully by the multiplex screening assay. Low enzyme activities were detected in 38 babies. Mutation analysis confirmed lysosomal storage disorders in 15 of them. The most frequent mutations were found for Fabry's disease (1 per 3859 births), followed by Pompe's disease (1 per 8684), and Gaucher's disease (1 per 17,368). The positive predictive values were 32% (95% CI 16-52), 80% (28-99), and 50% (7-93), respectively. Mutational analysis detected predominantly missense mutations associated with a late-onset phenotype.

INTERPRETATION

The combined overall proportion of infants carrying a mutation for lysosomal storage disorders was higher than expected. Neonatal screening for lysosomal storage disorders is likely to raise challenges for primary health-care providers. Furthermore, the high frequency of late-onset mutations makes lysosomal storage disorders a broad health problem beyond childhood.

FUNDING

Austrian Ministry of Health, Family, and Women.

Diagnostic dilemma: a young woman with Fabry disease symptoms, no family history, and a "sequencing cryptic" α-galactosidase a large deletion

Fabry disease, an X-linked lysosomal storage disorder, results from the deficient activity of α-galactosidase A (α-Gal A). In affected males, the clinical diagnosis is confirmed by the markedly decreased α-Gal A activity. However, in female heterozygotes, the α-Gal A activity can range from low to normal due to random X-chromosomal inactivation, and diagnostic confirmation requires identification of the family's α-Gal A gene mutation. In a young female who had occasional acroparesthesias, corneal opacities, and 15 to 50% of the lower limit of normal leukocyte α-Gal A activity, α-Gal A sequencing in two expert laboratories did not identify a confirmatory mutation, presenting a diagnostic dilemma. A renal biopsy proved diagnostic and renewed efforts to detect an α-Gal A mutation. Subsequent gene dosage analyses identified a large α-Gal A deletion confirming her heterozygosity, and she was started on enzyme replacement therapy. Thus, gene dosage analyses can detect large deletions (>50bp) in suspect heterozygotes for X-linked and autosomal dominant diseases that are "sequencing cryptic," resolving molecular diagnostic dilemmas.

Are MPS II heterozygotes actually asymptomatic? A study based on clinical and biochemical data, X-inactivation analysis and imaging evaluations

For some X-linked disorders the expressivity and penetrance in females are almost similar to those ones found in males. For mucopolysaccharidosis type II (MPS II), there are no studies in the literature trying to identify subtle signs and symptoms of this disease in heterozygotes. The objective of this study was to compare heterozygotes and non-heterozygotes for MPS II, in order to test the hypothesis that heterozygotes may present subtle manifestations of the disease. In this observational and transversal study we collected data on 40 Brazilian women with a positive familial history for MPS II that included clinical and physical exam, karyotype, pattern of X-inactivation, iduronate-2-sulfatase (IDS) activity in leukocytes and plasma, urinary glycosaminoglycans levels, computerized tomography scans (CT) of abdomen and spine, and brain magnetic resonance imaging. The Results showed the following: According to DNA analysis, 22 women were classified as heterozygote and 18 as non-heterozygotes. We did not find any abnormality on physical examination, karyotype, or spine CT. Also the pattern of X-inactivation was not different between the groups. Applying the Bonferroni's correction, both groups were found to differ only in relation to IDS activity in plasma and in leukocyte, which were lower in heterozygotes. In our investigation we did not find any evidence of subtle clinical manifestations of MPS II in heterozygotes. Our findings suggest there is no relation between the absence of clinical signs in these women and the occurrence of a favorable skewing pattern of X-inactivation.

Two novel alpha-galactosidase A mutations causing Fabry disease: A missense mutation M11V in a heterozygote woman and a nonsense mutation R190X in a hemizygote man

OBJECTIVES

To evaluate the nature of the molecular lesions in the alpha-galactosidase A gene of two patients having Fabry disease.

METHODS

Enzyme analyses were done using 4-methylumbellyferyl alpha-galactoside as substrate. Single stranded conformational polymorphism analysis and DNA sequencing were performed following PCR amplification of seven exons of alpha-galactosidase A gene.

RESULTS

Two new mutations, M11V and R190X, were identified. The female patient with M11V mutation had rheumatologic symptoms, microalbuminuria. The male patient with R190X mutation had a classical phenotype. M11V mutation is in the signal sequence of the peptide and may affect the targeting of the ribosomes to ER. R190X mutation causes premature termination, and probably leads to degradation of the protein.

CONCLUSION

This is the first study in our country investigating the molecular aspects of Fabry disease. It provides the molecular basis for understanding the underlying mechanism of Fabry disease, allows prenatal diagnosis and provides genotype/phenotype correlations.

Fabry disease complicating pregnancy

BACKGROUND

Few cases of Fabry disease, an X-linked lysosomal storage disorder, complicating pregnancy are reported.

CASE

A 36-year-old primigravida with known Fabry disease manifest with acroparesthesias, tinnitus, and hearing loss delivered a healthy unaffected infant at term.

CONCLUSION

A symptomatic Fabry carrier may experience an otherwise uncomplicated pregnancy in the absence of vital organ involvement.

Fabry disease

Fabry disease (FD) is a progressive, X-linked inherited disorder of glycosphingolipid metabolism due to deficient or absent lysosomal α-galactosidase A activity. FD is pan-ethnic and the reported annual incidence of 1 in 100,000 may underestimate the true prevalence of the disease. Classically affected hemizygous males, with no residual α-galactosidase A activity may display all the characteristic neurological (pain), cutaneous (angiokeratoma), renal (proteinuria, kidney failure), cardiovascular (cardiomyopathy, arrhythmia), cochleo-vestibular and cerebrovascular (transient ischemic attacks, strokes) signs of the disease while heterozygous females have symptoms ranging from very mild to severe. Deficient activity of lysosomal α-galactosidase A results in progressive accumulation of globotriaosylceramide within lysosomes, believed to trigger a cascade of cellular events. Demonstration of marked α-galactosidase A deficiency is the definitive method for the diagnosis of hemizygous males. Enzyme analysis may occasionnally help to detect heterozygotes but is often inconclusive due to random X-chromosomal inactivation so that molecular testing (genotyping) of females is mandatory. In childhood, other possible causes of pain such as rheumatoid arthritis and 'growing pains' must be ruled out. In adulthood, multiple sclerosis is sometimes considered. Prenatal diagnosis, available by determination of enzyme activity or DNA testing in chorionic villi or cultured amniotic cells is, for ethical reasons, only considered in male fetuses. Pre-implantation diagnosis is possible. The existence of atypical variants and the availability of a specific therapy singularly complicate genetic counseling. A disease-specific therapeutic option - enzyme replacement therapy using recombinant human α-galactosidase A - has been recently introduced and its long term outcome is currently still being investigated. Conventional management consists of pain relief with analgesic drugs, nephroprotection (angiotensin converting enzyme inhibitors and angiotensin receptors blockers) and antiarrhythmic agents, whereas dialysis or renal transplantation are available for patients experiencing end-stage renal failure. With age, progressive damage to vital organ systems develops and at some point, organs may start to fail in functioning. End-stage renal disease and life-threatening cardiovascular or cerebrovascular complications limit life-expectancy of untreated males and females with reductions of 20 and 10 years, respectively, as compared to the general population. While there is increasing evidence that long-term enzyme therapy can halt disease progression, the importance of adjunctive therapies should be emphasized and the possibility of developing an oral therapy drives research forward into active site specific chaperones.

Fabry disease: a review of current management strategies

Fabry disease is an X-linked inherited condition due to the absence or reduction of alpha-galactosidase activity in lysosomes, that results in accumulation of globotriaosylceramide (Gb3) and related neutral glycosphingolipids. Manifestations of Fabry disease include serious and progressive impairment of renal and cardiac function. In addition, patients experience pain, gastrointestinal disturbance, transient ischaemic attacks and strokes. Additional effects on the skin, eyes, ears, lungs and bones are often seen. The first symptoms of classic Fabry disease usually appear in childhood. Despite being X-linked, females can suffer the same severity of symptoms as males, and life expectancy is reduced in both females and males. Enzyme replacement therapy (ERT) can stabilize the progression of the disease. The rarity of the classic form of Fabry disease, however, means that there is a need to improve the knowledge and understanding that the majority of physicians have concerning Fabry disease, in order to avoid misdiagnosis and/or delayed diagnosis. This review aims to raise awareness of the signs and symptoms of Fabry disease; to provide a general diagnostic algorithm and to give an overview of the effects of ERT and concomitant treatments. We highlight a need to develop comprehensive international guidelines to optimize ERT and adjunctive therapy in patients with Fabry disease, including females and children.

Agalsidase alfa for enzyme-replacement therapy in Fabry disease

Fabry disease is an X-linked lysosomal storage disorder that is caused by a deficiency in the enzyme α-galactosidase A. Manifestations emerge during childhood, including neuropathic pain, hypohidrosis and gastrointestinal problems. Major organ involvement typically occurs during adulthood and includes progressive kidney dysfunction, cardiomyopathy and valve disease, and stroke. Enzyme-replacement therapy with agalsidase alfa has been available since 2001 and is associated with clinical benefit in adult men and women, as well as in children, with Fabry disease. The responses to agalsidase alfa include reduction in the severity of neuropathic pain, stabilization of kidney function and reduction in left ventricular mass in patients with baseline left ventricular hypertrophy. Several issues, including when to initiate treatment and whether long-term treatment will extend survival, remain to be answered. This article covers the clinical development of agalsidase alfa and the postmarketing reports of its safety and effectiveness.

Expression of the disease on female carriers of X-linked lysosomal disorders: a brief review

Most lysosomal diseases (LD) are inherited as autosomal recessive traits, but two important conditions have X-linked inheritance: Fabry disease and Mucopolysaccharidosis II (MPS II). These two diseases show a very different pattern regarding expression on heterozygotes, which does not seem to be explained by the X-inactivation mechanism only. While MPS II heterozygotes are asymptomatic in most instances, in Fabry disease most of female carriers show some disease manifestation, which is sometimes severe. It is known that there is a major difference among X-linked diseases depending on the cell autonomy of the gene product involved and, therefore, on the occurrence of cross-correction. Since lysosomal enzymes are usually secreted and uptaken by neighbor cells, the different findings between MPS II and Fabry disease heterozygotes can also be due to different efficiency of cross-correction (higher in MPS II and lower in Fabry disease). In this paper, we review these two X-linked LD in order to discuss the mechanisms that could explain the different rates of penetrance and expressivity observed in the heterozygotes; this could be helpful to better understand the expression of X-linked traits.

Frequency of Fabry disease in male and female haemodialysis patients in Spain

BACKGROUND

Fabry disease (FD), an X-linked lysosomal storage disorder, is caused by a reduced activity of the lysosomal enzyme alpha-galactosidase A. The disorder ultimately leads to organ damage (including renal failure) in males and females. However, heterozygous females usually present a milder phenotype with a later onset and a slower progression.

METHODS

A combined enzymatic and genetic strategy was used, measuring the activity of alpha-galactosidase A and genotyping the alpha-galactosidase A gene (GLA) in dried blood samples (DBS) of 911 patients undergoing haemodialysis in centers across Spain.

RESULTS

GLA alterations were found in seven unrelated patients (4 males and 3 females). Two novel mutations (p.Gly346AlafsX347 and p.Val199GlyfsX203) were identified as well as a previously described mutation, R118C. The R118C mutation was present in 60% of unrelated patients with GLA causal mutations. The D313Y alteration, considered by some authors as a pseudo-deficiency allele, was also found in two out of seven patients.

CONCLUSIONS

Excluding the controversial D313Y alteration, FD presents a frequency of one in 182 individuals (0.55%) within this population of males and females undergoing haemodialysis. Moreover, our findings suggest that a number of patients with unexplained and atypical symptoms of renal disease may have FD. Screening programmes for FD in populations of individuals presenting severe kidney dysfunction, cardiac alterations or cerebrovascular disease may lead to the diagnosis of FD in those patients, the study of their families and eventually the implementation of a specific therapy.

Clinical and biochemical studies in mucopolysaccharidosis type II carriers

The aim of the study was to characterize clinically and biochemically mucopolysaccharidosis type II (MPS II) heterozygotes. Fifty-two women at risk to be a carrier, with a mean age of 34.1 years (range 16-57 years), were evaluated through pedigree analysis, medical history, physical examination, measurement of iduronate sulfatase (IDS) activities in plasma and in leukocytes, quantification of glycosaminoglycans (GAGs) in urine, and analysis of the IDS gene. Eligibility criteria for the study also included being 16 years of age or older and being enrolled in a genetic counselling programme. The pedigree and DNA analyses allowed the identification of 40/52 carriers and 12/52 non-carriers. All women evaluated were clinically healthy, and their levels of urinary GAGs were within normal limits. Median plasma and leukocyte IDS activities found among carriers were significantly lower than the values found for non-carriers; there was, however, an overlap between carriers' and non-carriers' values. Our data suggests that MPS II carriers show lower plasma and leukocyte IDS activities but that this reduction is generally associated neither with changes in levels of urinary GAGs nor with the occurrence of clinical manifestations.

Fabry disease in children and the effects of enzyme replacement treatment

Fabry disease is a rare, X-linked inborn error of glycosphingolipid catabolism caused by a deficiency in the activity of the lysosomal enzyme, alpha-galactosidase A. In affected patients, the enzyme substrate, globotriaosylceramide (Gb3), accumulates in cells of various tissues and organs. Lysosomal accumulation of Gb3 begins in utero, and signs and symptoms of Fabry disease emerge in childhood and adolescence. The earliest presenting symptoms are typically neuropathic pain and gastrointestinal problems, which can have a substantial impact on health-related quality of life. Life-threatening major organ involvement is rare in young patients, but signs of kidney dysfunction (e.g., proteinuria), left ventricular hypertrophy, and stroke have been reported in children. There are two enzyme preparations for therapy: agalsidase alfa and beta. In two clinical trials of enzyme replacement therapy (ERT) with agalsidase alfa, including 37 children, boys demonstrated reductions in plasma Gb3 levels, and both boys and girls reported reductions in neuropathic pain and in the use of neuropathic pain medications. Heart rate variability, which is reduced in boys with Fabry disease, was statistically significantly improved with 6 months of agalsidase alfa treatment. In a single clinical study of agalsidase beta in children (n =16), skin Gb3 deposits and plasma Gb3 levels were reduced in boys. Differences exist in the administration and the safety profile of these two enzyme formulations. Follow-up of these cohorts and additional studies will be necessary to fully evaluate long-term efficacy of ERT in children with Fabry disease.

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.

X chromosome inactivation in clinical practice

X chromosome inactivation (XCI) is the transcriptional silencing of the majority of genes on one of the two X chromosomes in mammalian females. Females are, therefore, mosaics for two cell lines, one with the maternal X and one with the paternal X as the active chromosome. The relative proportion of the two cell lines, the X inactivation pattern, may be analyzed by simple assays in DNA from available tissues. This review focuses on medical issues related to XCI in X-linked disorders, and on the value of X inactivation analysis in clinical practice.

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.

Identification of GLA gene deletions in Fabry patients by Multiplex Ligation-dependent Probe Amplification (MLPA)

Fabry disease is an under-recognized X-linked lysosomal disorder, due to alpha-galactosidase A deficiency. Most of the mutations in the GLA gene are detectable using genomic sequencing analysis. However, deletions of one or more exons or deletion encompassing the entire gene are undetectable, especially in heterozygous females. The Multiplex Ligation-dependent Probe Amplification (MLPA) is an efficient tool for discovering these rearrangements. In this study two novel different deletions were detected using MLPA assay on two Fabry patients, both resulted mutation negative by sequencing analysis. These data suggest that this screening should be systematically included in genetic testing surveys of patients with Fabry disease.

Enzyme replacement therapy with agalsidase alfa in a cohort of Italian patients with Anderson-Fabry disease: testing the effects with the Mainz Severity Score Index

Anderson-Fabry disease (AFD) is a rare X-linked disorder caused by lysosomal storage of several glycosphingolipids, affecting virtually all organs and systems. Enzyme replacement therapy (ERT) for AFD has been available since 2001. Due to the highly variable nature of clinical manifestations in patients with AFD, it is very difficult to assess disease progression and the effects of therapy. We used the Mainz Severity Score Index (MSSI) as a measure of disease severity to study the effects of ERT in a population of 30 patients treated with agalsidase alfa for a median of 2.9 years (range, 1.0-6.2 years). Our data show that the MSSI captures the correlation between disease severity and both gender and age (1 - males performing worse than females at baseline and 2 - severity of diseases progresses with age in both sex). Furthermore, after at least 1 year of ERT, total MSSI scores were significantly lower than those at baseline (p < 0.001), suggesting a marked clinical improvement under ERT. In conclusion, the MSSI is a sensitive and useful tool for monitoring disease progression and assessing the effects of ERT in a population of patients from different treatment centres.

A study on serum IgE and clinical symptomatology of atopy in patients suffering from the lysosomal storage disorder Fabry disease

BACKGROUND

Lysosomal storage disorders may impair intracellular lysosomal processing of antigen with consequences for antibody production [e.g. immunoglobulin E (IgE)] and atopic disease status.

AIMS

Serum concentration of total IgE as well as clinical symptoms of atopic disorders as an indirect consequence of lysosomal impairment of antigen processing were studied in male and female Fabry disease (FD) patients with and without replacement of the missing lysosomal enzyme, alpha-galactosidase A (alpha-Gal A).

METHODS

Observational study in 31 adult FD patients with measurements of total serum IgE concentration. Questionnaire-derived data were obtained for atopic eczema (AE) skin lesions, allergic rhinoconjunctivitis (RCA) and allergic asthma (AA) at present or in the past.

RESULTS

Among 12 FD males under enzyme replacement therapy (ERT), 2 showed total IgE concentrations above 100 kU/L. Clinical symptoms for AA were found in 2, RCA and AE in 1, respectively. Among 10 FD females under ERT, 4 showed total IgE concentrations above 100 kU/L. Clinical symptoms for AA were found in 4, RCA in 2 and AE in 2. Among 9 females without ERT, 2 showed total IgE concentrations above 100 kU/L. Clinical symptoms for AA were found in 2, RCA in 2 and AE in none.

CONCLUSIONS

FD patients may demonstrate an increased total serum IgE concentration and may show symptoms of atopic disorders (AA, RCA, AE) in a prevalence rate comparable to international experience for individuals without FD. There was no difference between patients with and without ERT. Lack of detection of AE in females without ERT is suggested to be caused by the small sample size. FD patients without any alpha-Gal A activity prior to initiation of ERT should be in the focus of future studies.

Genetic polymorphisms of vitamin D receptor (VDR) in Fabry disease

Fabry disease, an X-linked inborn error of metabolism, is characterized by multi-organ involvement including cardiac signs of left ventricular hypertrophy and abnormal intima-medial (IMT) thickening of arteries, progressive renal failure, neurological involvement, and more. The vitamin D receptor (VDR) and an enzyme producing vitamin D3 result in an autocrine loop with direct effects on blood vessels. The purpose of this study is to assess VDR polymorphisms (BsmI, FokI, ApaI, and TaqI) relative to clinically important disease parameters using a disease-specific severity score (MSSI) and haplotype analysis. There were statistically significant differences between females (43% of 74 patients) and males in MSSI total scores, and in general and neurologic sub-scores. There appears to be a protective effect of the TaqI tt genotype so that there were significantly lower scores in clinical categories between those with the tt genotype versus those with the TT genotype. Multivariate models of haplotypes with MSSI scores reveal that T-A-f-B and t-a-F-b haplotypes of the VDR gene polymorphisms are significantly associated with variation in the Fabry phenotype. Despite the limitations of using the MSSI score as a clinical correlate, these results are provocative and further studies in larger cohorts with more males are recommended.

Prevalence of fabry disease in a cohort of 508 unrelated patients with hypertrophic cardiomyopathy

OBJECTIVES

We aimed to study the prevalence of Fabry disease (FD) in patients with hypertrophic cardiomyopathy (HCM).

BACKGROUND

There are limited and controversial data about the prevalence of FD in patients with HCM.

METHODS

We screened the plasma alpha-galactosidase A activity from 508 unrelated patients with HCM (328 men, 180 women, ages 58 +/- 16 years). Patients with low activity (0% to 30% of the normal control in men, and 0% to 50% in women) underwent genetic study of the GLA gene.

RESULTS

We found low plasma activity in 15 patients (3%). Three men had GLA mutations (0.9%): S238N (novel) in 2 and E358del (described) in 1. Two women had described mutations (1.1%): L89P and A143T. Three unrelated men had the D313Y variant previously associated with enzyme pseudo-deficiency. Two women had polymorphisms that did not segregate with the disease in their families. Five women (activity 39% to 47%) had no sequence variants. The familial studies allowed the diagnosis of 14 carriers: 6 women without Fabry manifestations, 3 women with cardiomyopathy, 2 men with renal and cardiac disease, 1 man with microhematuria, 1 woman with first-degree atrioventricular block, and a 32-year-old woman with only renal disease.

CONCLUSIONS

By means of a screening based on genotyping of patients with low plasma enzymatic activity, the prevalence of FD in our population of HCM is 1% (0.9% in men and 1.1% in women). This diagnosis is relevant, because it allows the identification of disease carriers that might benefit from enzyme replacement therapy.

Neurological manifestations in Fabry's disease

Fabry's disease is an X-linked lysosomal storage disorder caused by a defect in the gene that encodes the lysosomal enzyme alpha-galactosidase A. Symptoms arise because of accumulation of globotriaosylceramide in multiple organs, resulting in severely reduced quality of life and premature death. Neurological symptoms, such as burning sensations (occasionally accompanied by acroparesthesia) and stroke, are among the first to appear, and occur in both male and female patients. A delay in establishing the diagnosis of Fabry's disease can cause unnecessary problems, especially now that enzyme replacement treatment is available to prevent irreversible organ damage. Females with Fabry's disease who present with pain have often been ignored and misdiagnosed because of the disorder's X-linked inheritance. This Review will stress the importance of recognizing neurological symptoms for the diagnosis of Fabry's disease. The possible pathophysiological background will also be discussed.