Fabry disease 'The New Great Imposter': results of the French Observatoire in Internal Medicine Departments (FIMeD)

Outcomes and management of kidney transplant recipients with Fabry disease: a review

Fabry disease is an X-linked inheritable lysosomal storage disease caused by various mutations of the galactosidase α gene resulting in α-galactosidase deficiency. Chronic kidney disease (CKD) is one of the most significant consequences of Fabry disease, with risk of end-stage kidney disease (ESKD) in this population. Like for other patients with ESKD, kidney transplant is the optimal treatment for Fabry disease patients with ESKD. However, enzyme replacement therapy and newer Fabry disease treatments remain important to mitigate other end organ damage such as cardiomyopathy post transplantation. This review is a primer on Fabry disease, which examines the outcomes of disease in the context of kidney transplant prior to, and during, the enzyme replacement treatment era, medical treatment of kidney transplant recipients with Fabry disease, and progress in screening studies.

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.

Biochemical Mechanisms beyond Glycosphingolipid Accumulation in Fabry Disease: Might They Provide Additional Therapeutic Treatments?

Fabry disease is a rare X-linked disease characterized by deficient expression and activity of alpha-galactosidase A (α-GalA) with consequent lysosomal accumulation of glycosphingolipid in various organs. Currently, enzyme replacement therapy is the cornerstone of the treatment of all Fabry patients, although in the long-term it fails to completely halt the disease's progression. This suggests on one hand that the adverse outcomes cannot be justified only by the lysosomal accumulation of glycosphingolipids and on the other that additional therapies targeted at specific secondary mechanisms might contribute to halt the progression of cardiac, cerebrovascular, and renal disease that occur in Fabry patients. Several studies reported how secondary biochemical processes beyond Gb3 and lyso-Gb3 accumulation-such as oxidative stress, compromised energy metabolism, altered membrane lipid, disturbed cellular trafficking, and impaired autophagy-might exacerbate Fabry disease adverse outcomes. This review aims to summarize the current knowledge of these pathogenetic intracellular mechanisms in Fabry disease, which might suggest novel additional strategies for its treatment.

Association of Fabry Disease with Hearing Loss, Tinnitus, and Sudden Hearing Loss: A Nationwide Population-Based Study

Hearing loss and the related otologic manifestations are receiving increased scrutiny as significant causes of morbidity in Fabry disease. However, the relative risks of auditory deficits among patients with Fabry disease relative to the general population without a diagnosis of Fabry disease have not been studied. This study aims to explore the associations between Fabry disease and hearing-related manifestations using a nationwide population-based dataset. We identified study patients for this cross-sectional study from the 2015−2017 claims databases of the Taiwan Longitudinal Health Insurance Database 2005. We first identified 2312 patients aged over 20 years with a diagnosis of Fabry disease. We used propensity score matching to select five comparison patients per patient with Fabry disease and 11,560 comparison patients without Fabry disease. We used multivariable logistic regressions to estimate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for tinnitus, hearing loss, and sudden deafness among Fabry disease patients vs. comparison patients. Chi-square tests showed statistically significant differences between patients with and without Fabry disease in the prevalence rates of tinnitus (16.7% vs. 11.7%, p < 0.001), hearing loss (7.5% vs. 6.2%, p = 0.014) and sudden deafness (1.7% vs. 1.0%, p = 0.005). Multiple logistic regression revealed that patients with Fabry disease were more likely to suffer from tinnitus, hearing loss and sudden deafness, with adjusted odds ratios of 1.513 (95% CI = 1.336−1.713), 1.246 (95% CI = 1.047−1.483), and 1.681 (95% CI = 1.166−2.423), respectively. We found that Fabry disease is significantly associated with certain auditory manifestations, including hearing loss, sudden deafness, and tinnitus.

Balance control impairments in Fabry disease

Background

Fabry disease (FD) is a rare inherited lysosomal storage disorder caused by the deficiency of the enzyme alpha-galactosidase A. This deficiency leads to an accumulation of glycosphingolipids leading to progressive and multisystemic disease, including renal, cardiac, and neurological damages. FD may also have neuro-otological and visual impairments, which can generate postural control alterations, inner ear, and vision being involved in this function. This study aimed to evaluate the impact of FD on postural control.

Methods

In total, fourteen adult patients (8 men/6 women, mean age = 37.6 ± 11.4 years) and two children (mean age = 11 years) with FD and 19 healthy adults (12 men/7 women, mean age = 36.5 ± 16.9 years) and two healthy children (mean age = 10.5 years) took part in this study. Postural control was evaluated by a sensory organization test combining three visual situations (eyes open, eyes closed, and sway referenced visual surround motion) with two platform situations (stable platform and sway referenced platform motion), aiming to calculate a composite equilibrium score (CES), a high score being representative of good postural control. Somatosensory (R^SOM), visual (R^VIS), and vestibular (R^VEST) contributions to postural control were calculated, a low score reflecting a poor use of the indicated sensory input.

Results

The CES was lower in adult patients with FD compared with the healthy subjects (p < 0.001). R^VIS (p = 0.001) and R^VEST (p = 0.003) were lower in patients with FD compared with the control group, whereas no difference in R^SOM was observed.

Conclusion

Inner ear and visual pathologies associated with the central nervous system impairments are factors of postural control impairments. Physical activities, which can also be rehabilitative, by maintaining or increasing the weight of proprioception, may help diminish dependency on altered sensorial inputs.

Fabry disease prevalence in patients with familial Mediterranean fever: A cohort study

Background/Aim: Fabry disease is an X-chromosome inherited disease, which constitutes a rare disease group. Fabry disease has a wide spectrum of symptoms and some of these symptoms that are seen in other diseases. Familial Mediterranean fever (FMF) is a common disease in countries along the Mediterranean coast, including our country. Although typical episodes of recurrent high fever and abdominal pain occur, patients can also present with nonspecific symptoms and signs. This study aimed to investigate the presence of Fabry disease in patients with FMF. Methods: Information about this cohort study was given to all patients who were followed up with a diagnosis of FMF. Those who agreed to sign the informed consent form were included in the study. Fabry disease screening was performed by galactosidase alfa (GLA) gene analysis in female patients and by examining lysosomal alpha galactosidase A (AGALA) enzyme activity in male patients. When enzyme activity was found to be low in male patients, a GLA gene analysis was also performed. Results: Fabry disease was screened in a total of 189 patients with familial Mediterranean fever, and it was not detected in any of our patients. Low AGALA enzyme activity was detected in approximately 20% of the male patients. In the GLA gene analysis performed on these patients, any genetic mutation that could be associated with Fabry disease was not detected. Conclusion: People with Fabry disease or FMF can present with common symptoms, such as arthritis, proteinuria, and abdominal pain. In our study, Fabry disease was not found in any of patients who had a diagnosis of FMF. However, only a few publications on this subject are available. In studies conducted in our country and around the world, it has been shown that GLA gene mutations that may cause Fabry disease can be detected in patients with FMF. However, such a mutation was not detected in our study.

Left Ventricular Hypertrophy: Etiology-Based Therapeutic Options

Determining the etiologies of left ventricular hypertrophy (LVH) can be challenging due to the similarities of the different manifestations in clinical presentation and morphological features. Depending on the underlying cause, not only left ventricular mass but also left ventricular cavity size, or both, may increase. Patients with LVH remain asymptomatic for a few years, but disease progression will lead to the development of systolic or diastolic dysfunction and end-stage heart failure. As hypertrophied cardiac muscle disrupts normal conduction, LVH predisposes to arrhythmias. Distinguishing individuals with treatable causes of LVH is important for prevention of cardiovascular events and mortality. Athletic’s heart with physiological LVH does not require treatment. Frequent causes of hypertrophy include etiologies due to pressure/volume overload, such as systemic hypertension, hypertrophic cardiomyopathy, or infiltrative cardiac processes such as amyloidosis, Fabry disease, and sarcoidosis. Hypertension and aortic valve stenosis are the most common causes of LVH. Management of LVH involves lifestyle changes, medications, surgery, and implantable devices. In this review we systematically summarize treatments for the different patterns of cardiac hypertrophy and their impacts on outcomes while informing clinicians on advances in the treatment of LVH due to Fabry disease, cardiac amyloidosis, and hypertrophic cardiomyopathy.

Expert opinion on the recognition, diagnosis and management of children and adults with Fabry disease: a multidisciplinary Turkey perspective

This consensus statement by a panel of Fabry experts aimed to identify areas of consensus on conceptual, clinical and therapeutic aspects of Fabry disease (FD) and to provide guidance to healthcare providers on best practice in the management of pediatric and adult patients with FD. This consensus statement indicated the clinical heterogeneity of FD as well as a large number of pathogenic variants in the GLA gene, emphasizing a need for an individualized approach to patient care. The experts reached consensus on the critical role of a high index of suspicion in symptomatic patients and screening of certain at-risk groups to reveal timely and accurate diagnosis of FD along with an increased awareness of the treating physician about the different kinds of pathogenic variants and their clinical implications. The experts emphasized the crucial role of timely recognition of FD with minimal delay from symptom onset to definite diagnosis in better management of FD patients, given the likelihood of changing the disease's natural history, improving the patients' quality of life and the prognosis after enzyme replacement therapy (ERT) administered through a coordinated, multidisciplinary care approach. In this regard, this consensus document is expected to increase awareness among physicians about unique characteristics of FD to assist clinicians in recognizing FD with a well-established clinical suspicion consistent with pathogenic variants and gender-based heterogeneous clinical manifestations of FD and in translating this information into their clinical practice for best practice in the management of patients with FD.

Diagnosis of Fabry Disease in a Patient with a Surgically Repaired Congenital Heart Defect: When Clinical History and Genetics Make the Difference

Fabry disease (FD) is a multiorgan disease, which can potentially affect any organ or tissue, with the heart, kidneys, and central nervous system representing the major disease targets. FD can be suspected based on the presence of specific red flags, and the subsequent evaluation of the α-Gal A activity and GLA sequencing, are required to confirm the diagnosis, to evaluate the presence of amenable GLA mutation, and to perform a cascade program screening in family members. An early diagnosis is required to start an etiological treatment and to prevent irreversible organ damage. Here, we describe a case of a 37-years-old patient, with a surgically repaired congenital heart defect in his childhood, who had a late diagnosis of FD based on the clinical history and targeted genetic evaluation. This case highlights the importance to perform a correct phenotyping and definite diagnosis of FD, to start an early and appropriate treatment in the index patient, and a cascade clinical and genetic screening to identify other family members at risk, which may benefit from specific treatment and/or a close follow-up.

Understanding the ecosystem of patients with lysosomal storage diseases in Spain: a qualitative research with patients and health care professionals

Background

Lysosomal Storage Diseases (LSDs) are a group of Rare Diseases (RDs) caused by lysosomal enzyme deficiencies. Patients with LSDs suffer from a wide range of symptoms with a strong impact in their daily routines. In this study we aimed to explore the impact of the disease on the lives of patients with four LSDs, as well as how they experience Patient Journey from diagnosis to follow up. Unmet Needs (UNs) perceived by patients and clinicians were assessed to have a better understanding of which initiatives could improve LSDs management and especially those that could result in an improvement of patients’ quality of life.

Methods

Qualitative research was the research methodology selected for the study. It provides plentiful and holistic insights into people’s views and actions. The study was conducted through in-depth face-to-face semi-structured interviews.

Results

In total, 20 patients and 25 Health Care Professionals (HCPs) from different Spanish regions were interviewed. Patients perceived that the highest impact of the LSDs was on their daily routines, specifically on their emotional side, their work/school environment, their family and their social life. Regarding the Patient Journey experience, the worst perceived stage was the pre-diagnosis, where patients only reported negative perceptions, being the delay in diagnosis and misdiagnosis the most commented issues. On the contrary, the follow-up stage was the one with less negative perceptions. Overall, patients and HCPs agreed on the priority UNs, such as accelerating diagnosis, reducing bureaucracy for the treatment access and a more coordinated attention for the patients, not only among different physicians but also with other professionals such as genetic counselors or social workers.

Conclusions

Our data shows that there are still UNs to be addressed from the perspective of patients and HCPs. The main UN is accelerating diagnosis, which could be achieved by medical awareness and education, according to clinicians. A more comprehensive disease management was another main point to be worked on to improve LSD-patient experience and quality of life.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02168-7.

Genetic diseases mimicking multiple sclerosis

Multiple sclerosis (MS) is an inflammatory neurodegenerative disorder manifesting as gradual or progressive loss of neurological functions. Most patients present with relapsing-remitting disease courses. Extensive research over recent decades has expounded our insights into the presentations and diagnostic features of MS. Groups of genetic diseases, CADASIL and leukodystrophies, for example, have been frequently misdiagnosed with MS due to some overlapping clinical and radiological features. The delayed identification of these diseases in late adulthood can lead to severe neurological complications. Herein we discuss genetic diseases that have the potential to mimic multiple sclerosis, with highlights on clinical identification and practicing pearls that may aid physicians in recognizing MS-mimics with genetic background in clinical settings.

Corneal densitometry: a potential indicator for early diagnosis of Fabry disease

Purpose

To assess corneal densitometry in patients with Fabry disease (FD) and to compare corneal densitometry differences in FD patients to different corneal manifestations.

Methods

Ten participants (20 eyes) with FD and 10 age-matched healthy volunteers (20 eyes) were recruited. All participants were assessed by standardized ophthalmic examinations and the corneal densitometry analysis by Pentacam HR. Densitometry measurements were analyzed in standardized grayscale units.

Results

Seven patients developed conjunctival vessel tortuosity, cornea verticillata appeared in 6 patients, and two patients had Fabry cataract. Retinal vessel tortuosity occurred in 4 patients, and dilation of retinal vessels appeared in 3 patients, all symptoms occurred in both eyes. The first diagnosis of FD up to examination was 4.7 ± 3.23 years, and first ERT up to examination was 2.6 ± 2.27 years. The initial time to diagnosis was negatively related to the corneal densitometry value of the 0–2-mm (r = − 0.556, p = 0.011) and 2–6-mm (r = − 0.482, p = 0.032) zones in the posterior layer. FD group have significantly higher corneal densitometry in anterior 0–2-mm zone and 2–10-mm zone anterior and posterior layer than the control group (p ≤ 0.035, respectively). When divided into two groups by the existence of cornea verticillata, there was a statistically significant difference in the anterior layer, 6–10-mm zone (p = 0.031); in the central layer, 0–2 mm (p = 0.012), 2–6 mm (p = 0.001), 6–10 mm (p = 0.002), and total (p = 0.002); and in the posterior layer, 6–10 mm (p = 0.004) and total (p = 0.002).

Conclusions

FD patients show higher corneal densitometry, and corneal densitometry may have potential for early diagnosis and reminding progress of FD.

Screening for Fabry Disease in Kidney Transplant Recipients: Experience of a Multidisciplinary Team

Fabry disease (FD) is a rare cause of end-stage renal disease requiring kidney transplantation. Data on the incidence of unrecognized FD in kidney transplant recipients are scarce and probably underestimated. This study evaluated the incidence of FD in a population of kidney recipients, with a particular focus of the multidisciplinary approach for an early clinical assessment and therapeutic approach. Two hundred sixty-five kidney transplant recipients were screened with a genetic analysis for α-galactosidase A (GLA) mutation, with measurement of α-Gal A enzyme activity and Lyso Gb3 levels. Screening was also extended to relatives of affected patients. Seven patients (2.6%) had a GLA mutation. Two patients had a classic form of FD with Fabry nephropathy. Among the relatives, 15 subjects had a GLA mutation, and two had a Fabry nephropathy. The clinical and diagnostic assessment was completed after a median of 3.2 months, and mean time from diagnosis to treatment was 4.6 months. This study reported a high incidence of unrecognized GLA mutations in kidney transplant recipients. Evaluation and management by a multidisciplinary team allowed for an early diagnosis and treatment, and this would result in a delay in the progression of the disease and, finally, in better long-term outcomes.

Screening for Fabry Disease in Kidney Transplant Recipients: Experience of a Multidisciplinary Team

Fabry disease (FD) is a rare cause of end-stage renal disease requiring kidney transplantation. Data on the incidence of unrecognized FD in kidney transplant recipients are scarce and probably underestimated. This study evaluated the incidence of FD in a population of kidney recipients, with a particular focus of the multidisciplinary approach for an early clinical assessment and therapeutic approach. Two hundred sixty-five kidney transplant recipients were screened with a genetic analysis for α-galactosidase A (GLA) mutation, with measurement of α-Gal A enzyme activity and Lyso Gb3 levels. Screening was also extended to relatives of affected patients. Seven patients (2.6%) had a GLA mutation. Two patients had a classic form of FD with Fabry nephropathy. Among the relatives, 15 subjects had a GLA mutation, and two had a Fabry nephropathy. The clinical and diagnostic assessment was completed after a median of 3.2 months, and mean time from diagnosis to treatment was 4.6 months. This study reported a high incidence of unrecognized GLA mutations in kidney transplant recipients. Evaluation and management by a multidisciplinary team allowed for an early diagnosis and treatment, and this would result in a delay in the progression of the disease and, finally, in better long-term outcomes.

AA amyloidosis associated with Fabry disease

BACKGROUND

Fabry disease (FD) is the second most common lysosomal storage disorder, carrying a large morbidity and mortality. It has been recently reported that lysosomal storage disorders could cause inflammation and, subsequently, AA amyloidosis (AAA). Our aim was to describe AAA cases occurring in the course of FD.

PATIENTS AND METHODS

We described two patients displaying both AAA and FD and an additional case from the literature.

RESULTS

Three female patients originating from Europe (n = 2) and Algeria (n = 1) harboured heterozygous GLA mutations. The median age at AAA diagnosis was 61 years old. The diagnosis of Fabry was made before the diagnosis of AAA (n = 1) or concomitantly (n = 2). At AAA diagnosis, two patients displayed a nephrotic syndrome; all had inflammation.

CONCLUSION

Fabry disease can be associated with AAA, suggesting that an inflammatory component could exist in this genetic disease.

Global warming, heat-related illnesses, and the dermatologist

Global warming, provoked by the greenhouse effect of high levels of atmospheric gases (most notably carbon dioxide and methane), directly threatens human health and survival. Individuals vary in their capacity to tolerate episodes of extreme heat. Because skin is the organ tasked with heat dissipation, it is important for dermatologists to be versed in the physiology of cutaneous heat dissipation and cognizant of clinical settings in which the skin’s thermoregulatory responses may be impaired. When the external temperature is lower than that of the skin, the skin releases internal heat through direct thermal exchange with the environment, a process that is aided by an expansion of cutaneous blood flow and eccrine sweating. Cooling through the evaporation of sweat is effective even when the external temperature exceeds that of skin. Many factors, including environmental and physiological (e.g., age and sex), and pathological (e.g., preexisting illnesses, disorders of eccrine function, and medications) considerations, affect the skin’s capacity to thermoregulate. Identification of individuals at increased risk for heat-related morbidity and mortality will become increasingly important in the care of patients.

Recurrent fever of unknown origin: An overlooked symptom of Fabry disease

Objective

Fabry disease (FD) is a rare X‐linked lysosomal storage disorder due to the absent or deficient activity of lysosomal hydrolase a‐galactosidase A (α‐Gal A), which leads to the accumulation of its substrates in various organs and tissues. Classic clinical manifestations include angiokeratomas, proteinuria, renal failure, neuropathic pain, and left ventricular hypertrophy. Fever is one of the rare symptoms that may occur during FD.

Methods

Three Chinese Han patients with FD referred to Peking Union Medical College Hospital were reported. The complete medical records were established, and detailed data were collected. Whole‐exome sequencing by next‐generation sequencing and α‐Gal A enzyme activity assay were performed to confirm the diagnosis.

Results

These three patients all presented with recurrent fever of unknown origin initially, accompanied with arthralgia/arthritis and other symptoms. We identified two known variants in the GLA gene, c.1176_1179delGAAG and c.782G>A (p.G261D), and a novel variant c.440G>A (p.G147E) which is likely pathogenic in our patient.

Conclusions

FD should be considered as a rare cause of recurrent fever of unknown origin. The coexistence of gene variants related to systemic autoinflammatory diseases may make the clinical phenotypes of FD more complex and prone to recurrent fever.

When and How to Diagnose Fabry Disease in Clinical Pratice

Fabry disease is a frequent lysosomal storage disorder secondary to the deficiency of alpha-galactosidase A enzyme. This X-linked genetic disease realizes progressive and systemic manifestations that affect both male and female. Fabry disease may present as "classical", as "late-onset" or "non-classical" forms. Symptoms and organ involvements of classical Fabry disease are acral pain crisis, cornea verticillata, hypertrophic cardiomyopathy, stroke and chronic kidney disease with proteinuria. Other common symptoms are often poorly recognized, such as gastrointestinal or ear involvements. In classical Fabry disease, symptoms first appear during childhood or during teenage years in males, but later in females. Patients with non-classical or late-onset Fabry disease have delayed manifestations or a single-organ involvement. Diagnosis is therefore difficult when classical organ involvements are missing, in paucisymptomatic patients or in late-onset forms. Recognition of Fabry disease is important because effective treatments are available. They have to be prescribed early. In male, diagnosis is made with alpha-galactosidase A enzyme activity dosage in leukocyte, that is very low or null in classical forms and under 30 percent in late-onset forms. Diagnosis is more challenging in females who may express normal residual enzyme activity. Other plasmatic biomarkers, such as lyso-globotriaosylceramide are interesting, especially in females. In this review, we aimed to summarize main clinical manifestations of Fabry disease to know when to evoke Fabry disease and propose a practical diagnosis algorithm to know how to diagnose.

Higher rate of rheumatic manifestations and delay in diagnosis in Brazilian Fabry disease patients

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal disorder due to mutations in the GLA gene resulting in defective enzyme alpha-galactosidase A. FD patients are frequently misdiagnosed, commonly for rheumatic diseases. Determining pathogenicity of a mutation depends of in silico predictions but mostly on available clinical information and interpretation may change in light of evolving knowledge. Similar signs and symptoms in carriers of GLA gene genetic variants of unknown significance or of benign variants may hamper diagnosis. This study reviews rheumatic and immune-mediated manifestations in a cohort of Brazilian FD patients with classic mutations and also in subjects with GLA gene A143T and R118C mutations. Misdiagnoses, time to correct diagnosis or determination of GLA gene status, time to treatment initiation and reasons for treatment prescription in A143T and R118C subjects are reviewed.

METHODS

Genotype confirmed classic FD patients (n = 37) and subjects with GLA gene mutations A143T and R118C (n = 19) were referred for assessment. Subjects with R118C and A143T mutations had been previously identified during screening procedures at hemodialysis units. All patients were interviewed and examined by a rheumatologist with previous knowledge of disease and/or mutation status. A structured tool developed by the authors was used to cover all aspects of FD and of common rheumatic conditions. All available laboratory and imaging data were reviewed.

RESULTS

Thirty-seven consecutive FD patients were interviewed - 16 male / 21 female (mean age: 43.1 years) and 19 consecutive subjects with GLA gene mutations R118C and A143T were evaluated - 8 male / 11 female (mean age: 39.6 years); 15 [R118C] / 4 [A143T]. Misdiagnosis in FD patients occurred in 11 males (68.8%) and 13 females (61.9%) of which 10 males and 9 females were previously diagnosed with one or more rheumatic conditions, most frequently rheumatic fever or "rheumatism" (unspecified rheumatic disorder). Median time for diagnosis after symptom onset was 16 years (range, 0-52 years). Twenty-two patients were treated with enzyme replacement therapy (ERT) - 13 male and 9 female. Median time to ERT initiation after FD diagnosis was 0.5 years (range, 0-15 years). Rheumatic manifestations occurred in 68.4% of R118C and A143T subjects. Two subjects had been prescribed ERT because of renal disease [R118C] and neuropsychiatric symptoms [A143T].

CONCLUSION

Misdiagnoses occurred in 64.8% of FD patients, most frequently for rheumatic conditions. Median time for correct diagnosis was 16 years. Rheumatic manifestations are also frequent in subjects with GLA gene R118C and A143T mutations. These results reinforce the need to raise awareness and increase knowledge about Fabry disease among physicians, notably rheumatologists, who definitely have a role in identifying patients and determining disease burden. Decision to start treatment should consider expert opinion and follow local guidelines.

Identification of a novel loss-of-function mutation of the GLA gene in a Chinese Han family with Fabry disease

Background

Fabry disease is an X-linked recessive lysosomal disorder caused by deficient enzymatic activity of α-galactosidase A (α-Gal A). The insufficient enzymatic activity leads to excessive accumulation of glycosphingolipids, the substrates of the enzyme, in lysosomes in organs and tissues. Mutations in the α-Gal A gene (GLA, Xq22) have been proven to be responsible for Fabry disease.

Methods

In this study, we report a four-generation pedigree with left ventricular hypertrophy and chronic renal failure that was diagnosed by sequencing the GLA gene. An over expression system was constructed to evaluate the function of the detected mutation.

Results

We identified a novel mutation in exon 6 of the GLA gene, p.Asn278Lys, which completely co-segregated with the disease phenotype. The protein level of α-Gal A was significantly lower in the variant group than in the wild-type group; additionally, the pharmacological chaperone 1-deoxy-galactonojirimycin (DGJ) effectively normalized the enzyme activity of α-Gal A and its decline at the protein level.

Conclusions

This study is the first to report a novel loss-of-function mutation, p.Asn278Lys, in exon 6 of the GLA gene as a genetic aetiology for Fabry disease. In addition, we analysed the feasibility of DGJ as a therapeutic approach for this particular GLA mutation.

Mutations in the GLA Gene and LysoGb3: Is It Really Anderson-Fabry Disease?

Anderson-Fabry disease (FD) is a rare, progressive, multisystem storage disorder caused by the partial or total deficit of the lysosomal enzyme α-galactosidase A (α-Gal A). It is an X-linked, lysosomal enzymopathy due to mutations in the galactosidase alpha gene (GLA), encoding the α-Gal A. To date, more than 900 mutations in this gene have been described. In our laboratories, the study of genetic and enzymatic alterations related to FD was performed in about 17,000 subjects with a symptomatology referable to this disorder. The accumulation of globotriaosylsphingosine (LysoGb3) was determined in blood of positives. Exonic mutations in the GLA gene were detected in 471 patients (207 Probands and 264 relatives): 71.6% of mutations were associated with the classic phenotype, 19.8% were associated with the late-onset phenotype, and 8.6% of genetic variants were of unknown significance (GVUS). The accumulation of LysoGb3 was found in all male patients with a mutation responsible for classic or late-onset FD. LysoGb3 levels were consistent with the type of mutations and the symptomatology of patients. α-Gal A activity in these patients is absent or dramatically reduced. In recent years, confusion about the pathogenicity of some mutations led to an association between non-causative mutations and FD. Our study shows that the identification of FD patients is possible by associating clinical history, GLA gene analysis, α-Gal A assay, and blood accumulation of LysoGB3. In our experience, LysoGB3 can be considered a reliable marker, which is very useful to confirm the diagnosis of Fabry disease.

Neuroimaging in Fabry disease: current knowledge and future directions

Abstract

Fabry disease (FD) is a rare X-linked disorder characterised by abnormal progressive lysosomal deposition of globotriaosylceramide in a large variety of cell types. The central nervous system (CNS) is often involved in FD, with a wide spectrum of manifestations ranging from mild symptoms to more severe courses related to acute cerebrovascular events. In this review we present the current knowledge on brain imaging for this condition, with a comprehensive and critical description of its most common neuroradiological imaging findings. Moreover, we report results from studies that investigated brain physiopathology underlying this disorder by using advanced imaging techniques, suggesting possible future directions to further explore CNS involvement in FD patients.

Teaching Points

• Conventional neuroradiological findings in FD are aspecific.

• White matter hyperintensities represent the more consistent brain imaging feature of FD

• Abnormalities of the vasculature wall of posterior circulation are also consistent features.

• The pulvinar sign is not reliable as a finding pathognomonic for FD.

• Advanced imaging techniques have increased our knowledge about brain involvement in FD.

Fabry disease and multiple sclerosis misdiagnosis: the role of family history and neurological signs

Fabry disease (FD) is an X-linked inherited lysosomal storage disorder caused by α galactosidase A (α-gal A) deficiency. Central nervous system involvement and chronic white matter lesions are observed in both FD and multiple sclerosis (MS), which can confound the differential diagnosis. We analyzed the GLA gene, which encodes α-gal A, in 86 patients with clinical and neuroradiological findings consistent with MS to determine whether they had FD. We identified four women initially diagnosed with MS who had GLA mutations associated with FD. Our results indicate that family history besides neurological findings should be evaluated in patients with an uncertain diagnosis of MS. Also the involvement of organs outside the central nervous system can support the FD diagnosis.

Recommendations for the inclusion of Fabry disease as a rare febrile condition in existing algorithms for fever of unknown origin

Fever of unknown origin (FUO) is a rather rare clinical syndrome representing a major diagnostic challenge. The occurrence of more than three febrile attacks with fever-free intervals of variable duration during 6 months of observation has recently been proposed as a subcategory of FUO, Recurrent FUO (RFUO). A substantial number of patients with RFUO have auto-inflammatory genetic fevers, but many patients remain undiagnosed. We hypothesize that this undiagnosed subgroup may be comprised of, at least in part, a number of rare genetic febrile diseases such as Fabry disease. We aimed to identify key features or potential diagnostic clues for Fabry disease as a model of rare genetic febrile diseases causing RFUO, and to develop diagnostic guidelines for RFUO, using Fabry disease as an example of inserting other rare diseases in the existing FUO algorithms. An international panel of specialists in recurrent fevers and rare diseases, including internists, infectious disease specialists, rheumatologists, gastroenterologists, nephrologists, and medical geneticists convened to review the existing diagnostic algorithms, and to suggest recommendations for arriving at accurate diagnoses on the basis of available literature and clinical experience. By combining specific features of rare diseases with other diagnostic considerations, guidelines have been designed to raise awareness and identify rare diseases among other causes of FUO. The proposed guidelines may be useful for the inclusion of rare diseases in the diagnostic algorithms for FUO. A wide spectrum of patients will be needed to validate the algorithm in different clinical settings.

The impact of fever/hyperthermia in the diagnosis of Fabry: A retrospective analysis

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency of alpha-galactosidase A enzyme, which leads to the accumulation of its substrate, the globotriaosylceramide or Gb3, in many organs and tissues. Main clinical manifestations of FD are neuropathic pain, angiokeratomas, proteinuria and renal failure, left ventricular hypertrophy and stroke. Fever is also a possible symptom at the onset of the disease during childhood and adolescence, but it is frequently misdiagnosed, causing a delay in FD diagnosis.

METHODS

We retrospectively analysed the medical records in our series of 58 Fabry patients, focusing on the proportion of patients who exhibited fever as the main symptom at the onset of FD in order to evaluate the diagnostic delay in these patients.

FINDINGS

In our series, we found a significant proportion of patients with a history of fevers at the beginning of their medical history (20.7%; 12/58). 83% of patients with fever also exhibited acroparesthesias (10/12). Inflammatory markers were elevated in few of those cases (2/12). The mean diagnostic delay was 15.6±SD 12.8years.

INTERPRETATION

Fever emerged to be common as part of the FD clinical spectrum and it significantly contributed to the diagnostic delay encountered with this rare disease. Furthermore, our retrospective analysis indicated that FD patients commonly exhibit episodes of fever in association with other symptoms suggestive of FD (such as episodic pain crisis, acroparesthesias, hypo/anhydrosis, heat intolerance, fatigue and gastrointestinal distress). A careful analysis of the medical history in patients suffering fever could lead to an early and correct FD diagnosis. We believe that fever/hyperthermia, acroparesthesias and angiokeratoma should be considered for inclusion in the algorithm for Intermittent Fever of Unknown Origin (FUO) in order to improve the recognition of FD.

Sudden death following AV node ablation in a man with Fabry disease mimicking hypertrophic cardiomyopathy

We present a case of Fabry disease with an uncommon pattern of asymmetrical hypertrophy with septal prominence resulting in an erroneous diagnosis of hypertrophic cardilmyopathy clinically. The deceased presented for a medicolegal autopsy following his sudden death after an AV node ablation. Fabry disease continues to be an important misdiagnosis of hypertrophic cardiomyopathy in a clinical setting. Early diagnosis of Fabry disease is essential so that early treatment can be instituted.

p.R301X Mutation and Variable Phenotypic Appearance of Fabry Disease

BACKGROUND

Fabry disease is an X-linked disorder. Due to deficiency of the enzyme a-galactosidase A, neutral glycosphingolipids (primarily globotriaosylceramide) progressively accumulate within lysosomes of cells in various organ systems, resulting in a multi-system disorder, affecting both men and women. Misdiagnosis and delayed diagnosis are common because of the nature of Fabry disease.

CASE REPORT

We report a case of Fabry disease with a p.R301X (c.901 C>T) mutation in a 39-year-old man who was being treated for chronic sclerosing glomerulonephritis for 2 years. Family screening tests showed that the proband's mother, sister, and daughter had the same mutation with different phenotypes. Levels of α-galactosidase A were low in the proband and his mother and sister. Cornea verticillata and heart involvement were present in multiple family members. Agalsidase alfa treatment was started in patients where indicated.

CONCLUSIONS

Pedigree analysis is still a powerful, readily available tool to identify individuals at risk for genetic diseases and allows earlier detection and management of disease.

[Treatment of Fabry disease: Successes, failures, and expectations]

Fabry disease, an X-linked lysosomal storage disease, results from α-galactosidase A deficiency. Two different recombinant enzyme treatments (algalsidase alpha agalsidase beta) have been available since 2001 to treat a disease that affects not only men but also women. Enzyme replacement therapy promotes cell clearance of susbtrate, and improves some clinical parameters (heart, kidney damage, pain, quality of life). However, there is no proven efficacy to date on central nervous system lesions, on cardiac morbidity and mortality, nor on renal damage beyond a certain stage (proteinuria>1g/day and/or estimated glomerular filtration rate<60mL/min/1.73m(2)). In this review, we discuss the potential benefit of an early intervention, the vascular protective measures to be associated with enzyme therapy and their rationale, and some alternative treatments under development, such as chaperones and substrate molecules inhibitors.

Sudoscan as a noninvasive tool to assess sudomotor dysfunction in patients with Fabry disease: results from a case-control study

Hypohidrosis is a frequent and early symptom in patients with Fabry disease. Studies have reported improved sweating in patients treated with enzyme-replacement therapy. A new method, Sudoscan, has been developed that is noninvasive, is quantitative, and can quickly evaluate sweat gland function. It is based on the electrochemical reaction between sweat chlorides and stainless-steel electrodes in contact with the palms and soles. The aim of our study was to evaluate the Sudoscan as a tool to assess sudomotor dysfunction in patients with Fabry disease. Consecutive patients were prospectively recruited who had a diagnosis of Fabry disease, which had been confirmed genetically and/or by measurement of α-galactosidase activity in leukocytes. Healthy controls, matched (1:1) for age and sex, were also enrolled. Test results were expressed immediately as electrochemical skin conductance (ESC, µS) for hands and feet. Sudomotor dysfunction was considered absent, moderate, or severe if the ESC measured on the feet was >60 µS, between 60 and 40 µS, or <40 µS, respectively. Among the 18 patients, 11 had hypohidrosis or anhidrosis. Hand and feet ESCs were significantly lower in patients compared to their controls (P=0.0015 and P=0.0047, respectively). Among patients, 8/18 (44.5%) had a sudomotor dysfunction, moderate in three and severe in five cases. Hand and feet ESCs were significantly lower in those with hypohidrosis/anhidrosis compared to those without (P=0.0014 and P=0.0056, respectively). This study showed that Sudoscan provided a quick, noninvasive, and quantitative measurement of sudomotor function in Fabry disease patients.

Musculoskeletal manifestations of Fabry disease: A retrospective study

OBJECTIVES

Fabry disease is a rare X-linked metabolic disorder characterized by a deficiency in the enzyme alpha-galactosidase A. Both males and females can be affected. The main presenting symptom is pain in the extremities, whereas at a more advanced stage, the manifestations include hypertrophic cardiomyopathy, cardiac dysrhythmia, proteinuria, chronic kidney dysfunction, stroke, and hearing loss. When not diagnosed and treated, Fabry disease causes early death. No studies specifically designed to describe the musculoskeletal manifestations of Fabry disease are available.

METHODS

We conducted a single-center retrospective study of patients receiving follow-up at a Fabry disease referral center. We described the musculoskeletal manifestations and analyzed the differential diagnoses.

RESULTS

Our study included 40 patients belonging to 20 families, including 25 females with a mean age of 44.2 years (range, 20-76 years) and 15 males with a mean age of 40.1 years (range, 16-61 years). Mean age at the diagnosis of Fabry disease was 37.2 years (range, 7-71 years) in the females and 26.9 years (range, 9-51 years) in the males. Specific enzyme replacement therapy was given to 10 (40%) females and 12 (80%) males. Musculoskeletal manifestations were as follows: past or present pain in the extremities (13 females and 10 males), combined in some patients with vasomotor disorders in the extremities and telangiectasia; exercise intolerance (12 females and 12 males); osteoporotic fractures (2 brothers aged 45 and 44 years, respectively); osteoporosis (3 females, aged 57, 63, and 75 years, respectively), which contributed to death in the oldest patient; osteopenia (2 females aged 38 and 47 years, respectively; and 1 male aged 43 years); Charcot foot and lymphedema with serious infectious complications (4 males older than 40 years), with avascular osteonecrosis of the lower limbs in 2 cases; toe amputations (3 cases); bilateral lower-limb amputation (1 case); abnormally slender lower limbs (5 females and 8 males); acute gout (3 males with severe chronic kidney failure); and carpal tunnel syndrome (1 female and 1 male, both younger than 40 years). Mistaken diagnoses that were made at an early stage, contributing to delay the identification of Fabry disease, included rheumatic fever (2 females and 2 males), growing pains (2 males), pain with paralysis (1 female), chilblains of the lower limbs (1 female), and erythermalgia (1 female). In adulthood, the following mistaken diagnoses were made: Sjögren's syndrome and/or sicca syndrome (6 females), systemic sclerosis (1 male), dysautonomia (1 female), and familial Mediterranean fever (1 female).

CONCLUSION

The diagnosis of Fabry disease is usually delayed, due to confusion with more common disorders. Musculoskeletal manifestations may constitute the presenting symptoms. Past or present pain in the extremities is typical. Osteoporosis may develop early and become severe. Together with the family history, the presence of musculoskeletal manifestations can lead to the correct diagnosis by prompting alpha-galactosidase assays in males and genetic testing in females. Fabry disease is often responsible for musculoskeletal manifestations, of which the most common are pain in the extremities and osteoporosis. These manifestations can be inaugural and lead to diagnostic wanderings. They require specific treatment strategies.

Molecular and clinical studies in five index cases with novel mutations in the GLA gene

Fabry disease is a metabolic and lysosomal storage disorder caused by the functional defect of the α-galactosidase A enzyme; this defect is due to mutations in the GLA gene, that is composed of seven exons and is located on the long arm of the X-chromosome (Xq21-22). The enzymatic deficit is responsible for the accumulation of glycosphingolipids in lysosomes of different cellular types, mainly in those ones of vascular endothelium. It consequently causes a cellular and microvascular dysfunction. In this paper, we described five novel mutations in the GLA gene, related to absent enzymatic activity and typical manifestations of Fabry disease. We identified three mutations (c.846_847delTC, p.E341X and p.C382X) that lead to the introduction of a stop codon in positions 297, 341 and 382. Moreover we found a missense mutation (p.R227P) in the exon 5 of the GLA gene and a single point mutation (c.639+5 G>T) occurring five base pairs beyond the end of the exon 4. These mutations have never been found in our group of healthy control subjects >2300. The studied patients presented some clinical manifestations, such as cornea verticillata, hypo-anhidrosis, left ventricular hypertrophy, cerebrovascular disorders and renal failure, that, considering the null enzymatic activity, suggest that the new mutations reported here are related to the classic form of Fabry disease. The identification of novel mutations in patients with symptomatology referable to FD increases the molecular knowledge of the GLA gene and it gives clinicians an important support for the proper diagnosis of the disease.

Prevalence of Raynaud phenomenon and nailfold capillaroscopic abnormalities in Fabry disease: a cross-sectional study

Fabry disease (FD) is a lysosomal disorder leading to progressive systemic involvement, including microvascular damage that leads to neurological and cardiovascular disorders. We hypothesize that the latter could be documented at an early stage by performing a microcirculation study with nailfold capillaroscopy and evaluation of Raynaud phenomenon.The objective was to measure the prevalence of Raynaud phenomenon and nailfold capillaroscopic abnormalities in FD.This cross-sectional study included a standardized questionnaire and a nailfold capillaroscopy that assessed previously reported patterns in FD (dystrophic and giant capillaries, avascular fields, irregular architecture, dilatation and density of capillaries, hemorrhage), and was conducted on 32 Fabry patients and 39 controls. Capillaroscopic photographs were reviewed by 2 independent blinded investigators.Twelve Fabry patients (38%) suffered from Raynaud phenomenon, 5 were males (ie, 50% of male Fabry patients), compared with 2 controls (13%) (P < 0.001), of whom none were males (P < 0.001). Raynaud phenomenon was concomitant or before the occurrence of pain in the extremities in 42% of Fabry patients.More ramified capillaries were significantly observed in Fabry patients (12/32, 38%) than in controls (5/39, 13%, P = 0.016).Secondary Raynaud phenomenon should lead to screening for FD, especially in men. By extension, in high-risk populations for FD, the presence of Raynaud phenomenon and ramified capillaries should be assessed.

High variability of Fabry disease manifestations in an extended Italian family

Fabry disease (FD) is an inherited metabolic disorder caused by partial or full inactivation of the lysosomal hydrolase α-galactosidase A (α-GAL). The impairment of α-GAL results in the accumulation of undegraded glycosphingolipids in lysosomes and subsequent cell and microvascular dysfunctions. This study reports the clinical, biochemical, and molecular characterization of 15 members of the same family. Eight members showed the exonic mutation M51I in the GLA gene, a disease-causing mutation associated with the atypical phenotype. The clinical history of this family highlights a wide phenotypic variability, in terms of involved organs and severity. The phenotypic variability of two male patients is not related to differences in α-GAL enzymatic activity: though both have no enzymatic activity, the youngest shows severe symptoms, while the eldest is asymptomatic. It is noticeable that for two female patients with the M51I mutation the initial clinical diagnosis was different from FD. One of them was diagnosed with Familial Mediterranean Fever, the other with Multiple Sclerosis. Overall, this study confirms that the extreme variability of the clinical manifestations of FD is not entirely attributable to different mutations in the GLA gene and emphasizes the need to consider other factors or mechanisms involved in the pathogenesis of Fabry Disease.

Fabry disease in infancy and early childhood: a systematic literature review

PURPOSE

Fabry disease is a pan-ethnic, progressive, X-linked genetic disorder that commonly presents in childhood and is caused by deficient activity of the lysosomal enzyme alpha-galactosidaseA (α-gal A). Symptoms of Fabry disease in the pediatric population are well described for patients over five years of age; however, data are limited for infancy and early childhood. The purpose of this article is to delineate the age of detection for specific Fabry symptoms in early childhood.

METHODS

A systematic retrospective analysis of PubMed indexed, peer-reviewed publications and case reports in the pediatric Fabry population was performed to review symptoms in patients reported before 5 years of age.

RESULTS

The most frequently reported symptom in all age groups under 5 years was acroparesthesias/neuropathic pain, reported in 9 children, ranging in age from 2.0-4.0 years. Also notable is the frequency of gastrointestinal issues reported in 6 children aged 1.0-4.1 years of age.

CONCLUSION

This article finds clear evidence that symptoms can occur in early childhood, before age 5 years. Given early presenting symptoms and the ability to monitor these disease hallmarks, a timely referral to a medical geneticist or other specialty clinician experienced in managing children with Fabry disease is strongly indicated.

Cerebral hemodynamics and endothelial function in patients with Fabry disease

Background

Cerebral vasculopathy have been described in Fabry disease, in which altered cerebral blood flow, vascular remodelling or impairment of endothelial function could be involved. Our study aims to evaluate these three possibilities in a group of Fabry patients, and compare it to healthy controls.

Methods

Cerebral hemodynamics, vascular remodelling and systemic endothelial function were investigated in 10 Fabry patients and compared to data from 17 healthy controls. Transcranial Doppler was used to study blood flow velocity of intracranial arteries and cerebral vasomotor reactivity. For the study of vascular remodelling and endothelial function, intima-media thickness of common carotid arteries, flow-mediated dilation in brachial artery and serum levels of soluble VCAM-1, TNF-α, high-sensitive CRP and IL-6 were measured. Differences between groups were evaluated using appropriate tests.

Results

No relevant differences were observed in cerebral hemodynamic parameters, intima-media thickness or flow-mediated dilation. There was a trend for low serum levels of IL-6 and high serum levels of TNF-α and high-sensitive CRP in Fabry patients; plasma concentrations of soluble VCAM-1 were significantly higher in Fabry disease patients than in healthy volunteers (p = 0.02).

Conclusions

In our sample, we did not find relevant alterations of cerebral hemodynamics in Fabry disease patients. Increased levels of plasmatic endothelial biomarkers seem to be the most important feature indicative of possible vascular dysfunction in Fabry disease patients.

Difficulties and barriers in diagnosing Fabry disease: what can be learnt from the literature?

INTRODUCTION

Fabry disease (FD) is an X-linked disorder of glycosphingolipid metabolism caused by deficiency of the lysosomal enzyme alpha galactosidase A. Clinical features include neuropathic pain, rash, proteinuria renal failure, stroke and cardiomyopathy accompanied by a reduced life expectancy. Patients report an average delay of > 10 years between symptom onset and diagnosis. Newborn screening studies suggest a much higher prevalence than that found on population studies supporting the notion that FD is under-diagnosed.

AREAS COVERED

Four key challenges in the diagnosis of FD and strategies to overcome them are discussed. The clinical features of FD are highly heterogeneous resulting in patients presenting to many different specialists, often with non-specific symptoms with a wide differential diagnosis. The pathophysiological mechanisms underlying this are poorly understood and the prediction of pathogenicity on the basis of gene mutation analysis can be problematic. While the availability of treatment adds an impetus to make the correct diagnosis, our understanding of when and if treatment may be required in a specific individual is incomplete.

EXPERT OPINION

Improving diagnostic rates of FD requires a greater awareness of the disorder among physicians to whom patients may present, new strategies to determine the pathogenicity of novel mutations and a greater understanding of the natural history of FD across the phenotypic spectrum. Collaborative clinical and laboratory research is vital in furthering knowledge of the underlying mechanisms of this disorder and how they may be impacted by current or future therapies.

Angiokeratomas – When is a few too many?

Many patients have a few scattered angiokeratoma and we reassure them that this it is normal; however, if they are numerous, Fabry disease should be considered and the family history should be checked.

Analysis of the landscape of biologically-derived pharmaceuticals in Europe: dominant production systems, molecule types on the rise and approval trends

A thorough sort of the human drugs approved by the European Medicines Agency (EMA) between its establishment in 1995 until June 2012 is presented herein with a focus on biologically-derived pharmaceuticals. Over 200 (33%) of the 640 approved therapeutic drugs are derived from natural sources, produced via recombinant DNA technology, or generated through virus propagation. A breakdown based on production method, type of molecule and therapeutic category is presented. Current EMA approvals demonstrate that mammalian cells are the only choice for glycoprotein drugs, with Chinese hamster ovary cells being the dominant hosts for their production. On the other hand, bacterial cells and specifically Escherichia coli are the dominant hosts for protein-based drugs, followed by the yeast Saccharomyces cerevisiae. The latter is the dominant host for recombinant vaccine production, although egg-based production is still the main platform of vaccine provision. Our findings suggest that the majority of biologically-derived drugs are prescribed for cancer and related conditions, as well as the treatment of diabetes. The approval rate for biologically-derived drugs shows a strong upward trend for monoclonal antibodies and fusion proteins since 2009, while hormones, antibodies and growth factors remain the most populous categories. Despite a clear pathway for the approval of biosimilars set by the EMA and their potential to drive sales growth, we have only found approved biosimilars for three molecules. In 2012 there appears to be a slow-down in approvals, which coincides with a reported decline in the growth rate of biologics sales.