Screening of family members of chronic kidney disease patients with Fabry disease mutations: a very important and underrated task / Triagem de familiares de pacientes com doença renal crônica com mutação na doença de Fabry: uma tarefa muito importante e subestimada

ABSTRACT Introduction: Fabry disease is a chronic, progressive, and multi-system hereditary condition, related to an Xq22 mutation in X chromosome, which results in deficiency of alpha-galactosidase enzyme, hence reduced capacity of globotriaosylceramide degradation. Objectives: to evaluate the prevalence of Fabry disease (FD) mutations, as well as its signs and symptoms, among relatives of chronic kidney disease (CKD) patients diagnosed with FD during a previously conducted study, named "Clinical and epidemiological analysis of Fabry disease in dialysis centers in Brazil". Methods: a cross-sectional study was carried out, and data was collected by interviewing the relatives of patients enrolled in the Brazil Fabry Kidney Project and blood tests for both Gb3 dosage and genetic testing. Results: Among 1214 interviewed relatives, 115 (9.47%) were diagnosed with FD, with a predominance of women (66.10%). The most prevalent comorbidities were rheumatologic conditions and systemic hypertension (1.7% each), followed by heart, neurological, cerebrovascular diseases, and depression in 0.9% of individuals. Intolerance to physical exercise and tiredness were the most observed symptoms (1.7%), followed by periodic fever, intolerance to heat or cold, diffuse pain, burn sensation or numbness in hands and feet, reduced or absent sweating, as well as abdominal pain after meals in 0.9%. Conclusion: We found a prevalence of Fabry disease in 9.47% of relatives of CKD patients with this condition, remarkably with a 66.1% predominance of women, which contrasts with previous reports. The screening of family members of FD patients is important, since it can lead to early diagnosis and treatment, thus allowing better quality of life and improved clinical outcomes for these individuals.

RESUMO Introdução: A doença de Fabry é uma condição hereditária crônica, progressiva e multissistêmica, relacionada a uma mutação Xq22 no cromossomo X, que resulta em deficiência da enzima alfa-galactosidase, diminuindo a capacidade de degradação da globotriaosilceramida. Objetivos: avaliar a prevalência de mutações na doença de Fabry, bem como seus sinais e sintomas, em familiares de pacientes com doença renal crônica (DRC) diagnosticados com DF durante um estudo realizado anteriormente, denominado "Análise clínica e epidemiológica da doença de Fabry em centros de diálise no Brasil". Métodos: foi realizado um estudo transversal e os dados foram coletados através da entrevista com familiares de pacientes inscritos no Projeto Rim Fabry Brasil e exames de sangue para dosagem de Gb3 e testes genéticos. Resultados: Dos 1,214 familiares entrevistados, 115 (9,47%) foram diagnosticados com DF, com predomínio de mulheres (66,10%). As comorbidades mais prevalentes foram condições reumatológicas e hipertensão arterial sistêmica (1,7% cada), seguidas por doenças cardíacas, neurológicas, cerebrovasculares e depressão em 0,9% dos indivíduos. Intolerância ao exercício físico e cansaço foram os sintomas mais observados (1,7%), seguidos de febre periódica, intolerância ao calor ou ao frio, dor difusa, sensação de queimação ou dormência nas mãos e nos pés, sudorese reduzida ou ausente, além de dor abdominal após refeições em 0,9%. Conclusão: Encontramos uma prevalência da doença de Fabry em 9,47% dos familiares de pacientes com DRC com essa condição, notadamente com uma predominância de 66,1% de mulheres, o que contrasta com relatos anteriores. A triagem de familiares de pacientes com DF é importante, pois pode levar ao diagnóstico e tratamento precoces, permitindo melhor qualidade de vida e melhores resultados clínicos para esses indivíduos.

Rare inherited kidney diseases: an evolving field in Nephrology / Doenças renais hereditárias raras: um campo em evolução na Nefrologia

Abstract There are more than 150 different rare genetic kidney diseases. They can be classified according to diagnostic findings as (i) disorders of growth and structure, (ii) glomerular diseases, (iii) tubular, and (iv) metabolic diseases. In recent years, there has been a shift of paradigm in this field. Molecular testing has become more accessible, our understanding of the underlying pathophysiologic mechanisms of these diseases has evolved, and new therapeutic strategies have become more available. Therefore, the role of nephrologists has progressively shifted from a mere spectator to an active player, part of a multidisciplinary team in the diagnosis and treatment of these disorders. This article provides an overview of the recent advances in rare hereditary kidney disorders by discussing the genetic aspects, clinical manifestations, diagnostic, and therapeutic approaches of some of these disorders, named familial focal and segmental glomerulosclerosis, tuberous sclerosis complex, Fabry nephropathy, and MYH-9 related disorder.

Resumo As doenças renais genéticas raras compreendem mais de 150 desordens. Elas podem ser classificadas segundo achados diagnósticos como (i) distúrbios do crescimento e estrutura, (ii) doenças glomerulares, (iii) tubulares e (iv) metabólicas. Nos últimos anos, houve uma mudança de paradigma nesse campo. Os testes moleculares tornaram-se mais acessíveis, nossa compreensão sobre os mecanismos fisiopatológicos subjacentes a essas doenças evoluiu e novas estratégias terapêuticas foram propostas. Portanto, o papel do nefrologista mudou progressivamente de mero espectador a participante ativo, parte de uma equipe multidisciplinar, no diagnóstico e tratamento desses distúrbios. O presente artigo oferece um panorama geral dos recentes avanços a respeito dos distúrbios renais hereditários raros, discutindo aspectos genéticos, manifestações clínicas e abordagens diagnósticas e terapêuticas de alguns desses distúrbios, mais especificamente a glomeruloesclerose segmentar e focal familiar, complexo da esclerose tuberosa, nefropatia de Fabry e doença relacionada ao MYH9.

Fabry disease: genetics, pathology, and treatment

SUMMARY Fabry disease (FD) is a recessive monogenic inheritance disease linked to chromosome X, secondary to mutations in the GLA gene. Its prevalence is estimated between 1:8,454 and 1:117,000 among males and is probably underdiagnosed. Mutations in the GLA gene lead to the progressive accumulation of globotriaosylceramide (Gb3). Gb3 accumulates in lysosomes of different types of cells of the heart, kidneys, skin, eyes, central nervous system, and gastrointestinal system, and may lead to different clinical scenarios. The onset of symptoms occurs during childhood, with acroparesthesia, heat intolerance, and gastrointestinal symptoms, such as nausea, vomiting, abdominal pain, and neuropathic pain. Subsequently, symptoms related to progressive impairment appear, such as angiokeratomas, cornea verticillata, left ventricular hypertrophy, myocardial fibrosis, proteinuria, and renal insufficiency. The latter being the main cause of death in FD. The gold standard for diagnosis is the genetic analysis in search of mutation, in addition to family history. In homozygous patients, the enzyme activity can also be used. Once the diagnosis is confirmed, the patient and their family should receive genetic counseling. The treatment, in turn, currently focuses mainly on replacing the enzyme that is absent or deficient by means of enzyme replacement therapy, with the purpose of avoiding or removing deposits of Gb3. Chaperones can also be used for the treatment of some cases. It is considered that the specific treatment should be initiated as soon as a diagnosis is obtained, which can change the prognosis of the disease.

Ocular findings in Fabry disease in Colombian patients / Manifestaciones oculares de la enfermedad de Fabry en pacientes colombianos

ABSTRACT Fabry disease is a rare X-linked disorder caused by an alpha-galactosidase enzyme deficiency, which leads to a progressive lysosomal glycosphingolipids accumulation, mainly globotriaosylceramide, in multiple organism tissues including the eye. This case series describes the first ophthalmological Colombian report of Fabry disease highlighting the importance of ocular signs as markers of the disease, useful in diagnosis and treatment to avoid long-term complications that lead to a morbi-mortality increment. We describe five cases of Fabry disease from Bogotá, Colombia, including a complete clinical history, ophthalmologic, optometric examination, and photographs. We found that all patients had refractive defects and that in all cases corneal verticillata pattern was found. Four patients presented with posterior capsule lens brown-beige deposits and four patients had conjunctival and retinal tortuous vessels. A complete ophthalmologic examination is important for prompt diagnosis, which is key to starting a multidisciplinary treatment and reducing morbi-mortality.

RESUMEN La enfermedad de Fabry es un raro trastorno ligado al cromosoma X causado por deficiencia de la enzima alfa-galactosidasa y la consiguiente y progresiva acumulación lisosómica de glucoesfingolípidos, especialmente la globotriaosilceramida, en múltiples tejidos del organismo, incluido el ojo. En este reporte se presenta la primera serie de casos de manifestaciones oculares de la enfermedad de Fabry en Colombia, resaltando la importancia de los signos oculares como ayuda para el diagnóstico temprano. Se presentan cinco casos de la enfermedad en Bogotá y se da cuenta de las historias clínicas y los exámenes oftalmológicos y de optometría, y se incluyen fotografías. En todos los pacientes se hallaron errores de refracción y se evidenció el patrón de córnea verticillata. Cuatro pacientes presentaban depósitos de color café y castaño claro en la cápsula posterior del cristalino, y cuatro tenían tortuosidad vascular conjuntival y retiniana. El examen oftalmológico completo es importante para hacer un diagnóstico oportuno con el fin de iniciar el tratamiento multidisciplinario y reducir la morbimortalidad.

Familial angiokeratoma corporis diffusum without identified enzyme defect.

Angiokeratoma corporis diffusum is the cutaneous hallmark of several rare inherited lysosomal diseases associated with specific enzyme deficiencies in the metabolism of glycoproteins, most notably Fabry disease. These defects result in many systemic manifestations. Here, we report a rare familial case of angiokeratoma corporis diffusum that developed at puberty with no major systemic manifestations and no underlying enzyme defect or gene mutation. Familial angiokeratoma corporis diffusum without identified enzyme defect appears to be a distinct clinical entity with a benign course.

Fabry disease: clinical and genotypic aspects of three cases in first degree relatives

Fabry disease is an X-linked, lysosomal storage disease caused by the inherited deficiency of the enzyme α-galactosidase A. The diagnosis is usually late, with renal, cardiovascular and/or cerebral complications that reduce life expectancy. Angiokeratomas are asymptomatic lesions present as the initial manifestation and usually less appreciated. Their detection is important for early diagnosis and institution of treatment with enzyme replacement therapy, which prevents late complications reducing morbidity and mortality. We report a case of a male teenager with acroparestesias and angiokeratomas. Family medical research discovered that his mother and brother had similar signs and symptoms and that the three patients had the same mutation in the gene encoding the enzyme, confirming the diagnosis.

Doença de Anderson-Faby: manifestações cardíacas: [revisão] / Anderson Fabry's disease: cardiac manifestations: [review]

A doença de Anderson-Fabry é uma desordem genética ligada ao cromossomo X, causada por deficiência parcial ou completa de uma enzima lisossomal, α-galactosidase A, resultando em deposição de glicoesfingolipídios e levando à morte prematura, principalmente por complicações renais, cardíacas e cerebrovasculares. O envolvimento cardíaco é, geralmente, parte de um acometimento sistêmico presente na quarta década de vida. Entretanto, uma variante da doença com acometimento cardíaco predominante tem sido reconhecida. Hipertrofia concêntrica do ventrículo esquerdo é um achado comum e essa doença deve ser suspeitada em pacientes com hipertrofia inexplicada do ventrículo esquerdo.

Fabry disease - importance of screening in cornea verticillata: case report / Doença de Fabry - importância do rastreamento em córnea verticilata: relato de caso

Fabry disease is an X-linked disease of glycosphingolipid (GL) metabolism. The accumulation of GL in tissues can affect multiple organ systems. Initial symptoms includes episodes of severe pain in the extremities, cornea verticillata and skin lesions. In late stages, kidney, heart and brain can be involved. This report attempts for importance of cornea verticillata in the diagnosis of Fabry disease in a young patient with pain in the lower limb extremities.

A doença de Fabry é um erro inato no metabolismo de glicosfingolipides (GL) ligado ao cromossomo X. O acúmulo de GL nos tecidos pode afetar múltiplos órgãos e sistemas. Os sintomas iniciais incluem episódios de dor nas extremidades, córnea verticilata e lesões na pele. Em estágios avançados, os rins, coração e cérebro podem ser envolvidos. Este relato de caso enfatiza para importância da córnea verticilata para o diagnóstico de doença de Fabry em paciente jovem com dor nos membros inferiores.

Fabry disease: A treatable lysosomal storage disorder.

Fabry disease is a lysosomal storage disease with an X-linked inheritance pattern, which presents in childhood as acroparaesthesias. Its non-specific symptoms often lead to delays in the diagnosis. We report the case of a 13-year-old boy who presented with typical acroparaesthesia of Fabry disease, his younger brother had gastrointestinal manifestations of the disease and their mother’s symptoms suggested that she is a carrier. Enzyme replacement therapy helped in ameliorating the patient’s symptoms and preventing complications such as renal failure, stroke and cardiovascular disorders.

Enfermedad de Fabry-Anderson: angioqueratomas: acroparestesias / Disease of Fabry-Anderson: angioqueratomas: acroparestesias

Paciente de sexo masculino de 32 años de edad que consulta al Servicio de Dermatología por angioqueratomas diseminados y acroparestesias de 20 años de evolución. Con la sospecha de enfermedad de Fabry-Anderson, se solicita dosaje enzimático de alta galactosidasa A, confirmando el diagnóstico.

Prevalência da doença de fabry em pacientes portadores de doençarenal crônica submetidos à hemodiálise em Natal – RN / Prevalence of fabry disease in patients with chronic kidney disease onhemodialysis in Natal – RN, Brazil

Introdução: A Doença de Fabry é uma doença genética de depósito lisossômico caracterizada pela deficiência da enzima α-galactosidase A (ceramidatrihexosidase). Isso gera acúmulo de globotriaosilceramida (GL-3) no endotélio vascular, podendo ocasionar complicações renais, cardíacas ecerebrovasculares. Diante da terapia de reposição enzimática, torna-se essencial o diagnóstico desta doença, o que pode ser conseguido através de umrastreamento de pacientes em hemodiálise. Objetivos: O presente estudo objetivou determinar a prevalência da doença em pacientes portadores dedoença renal crônica em hemodiálise na cidade de Natal – RN, avaliando as principais co-morbidades associadas. Métodos: Foram selecionadosindivíduos do sexo masculino em hemodiálise, entre 18 e 65 anos, excluindo-se pacientes cuja etiologia da falência renal era: diabetes mellitus, lupuseritematoso sistêmico, nefropatia obstrutiva, pielonefrite crônica e doença renal policística. Uma amostra sanguínea foi coletada para avaliação da atividadeda α-galactosidase A em papel de filtro. Os pacientes com valores inferiores a 2,5μmol/L/h tiveram a atividade enzimática testada em leucócitos eresponderam a um questionário sobre as manifestações clínicas relacionadas. Resultados: Dos 191 pacientes, 16 (8,3%) cursaram com atividadeenzimática em papel de filtro inferior a 2,5μmol/L/h. Apenas um paciente (0,52%) apresentou dosagem da atividade enzimática em leucócitos inferior aovalor da normalidade, sendo compatível com Doença de Fabry. Não foram encontradas as manifestações típicas da doença neste paciente. Conclusão:Observou-se uma prevalência da Doença de Fabry de 0,52% dentre os pacientes estudados nos centros de hemodiálise de Natal – RN no ano de 2006.

Introduction: Fabry Disease is a genetic illness of lisosomic deposition characterized by the deficiency of the enzyme alpha-galactosidase A (ceramidetrihexosidase), generating an accumulation of globotriaosilceramide (GL-3) in the vascular endothelium, capable of leading to renal, cardiac andcerebrovascular complications. Faced with the therapeutic possibility of enzymatic supplementation, the diagnosis of this disease becomes essential, andcan be achieved through the screening of hemodialysis patients. Aims: The present study aimed at determining the prevalence of Fabry Disease in patientswith chronic kidney disease undergoing hemodialysis in the city of Natal, Rio Grande do Norte, Brazil, evaluating the main associated comorbidities.Methods: The sample consisted of male subjects between 18 and 65 years of age, undergoing hemodialysis, excluding patients whose etiology of renalfailure was diabetes mellitus, systemic lupus erythematosus, obstructive nephropathy, chronic pyelonephritis, or polycystic kidney disease. A blood samplewas collected for an evaluation of alpha-galactosidase A activity in filter paper. Patients with values inferior to 2.5 μmol/L/h had their enzymatic activity testedin leukocytes, and a questionnaire about related clinical manifestations was applied. Results: From 191 patients, 16 (8.3%) had an enzymatic activity infilter paper inferior to 2.5 μmol/L/h. Only one patient (0.52%) exhibited a level of enzymatic activity in leukocytes inferior to the normal value, compatible withFabry Disease. The typical manifestations of the disease were not found in this case. Conclusion: A prevalence of Fabry Disease of 0.52% was observedamong patients studied in hemodialysis centers in Natal in 2006.

Genomic analysis of Brazilian patients with Fabry disease

Fabry disease is an X-linked lysosomal disorder due to a-galactosidase A deficiency that causes storage of globotriaosylceramide. The gene coding for this lysosomal enzyme is located on the long arm of the X chromosome, in region Xq21.33-Xq22. Disease progression leads to vascular disease secondary to involvement of kidney, heart and the central nervous system. Detection of female carriers based solely on enzyme assays is often inconclusive. Therefore, mutation analysis is a valuable tool for diagnosis and genetic counseling. Many mutations of the a-galactosidase A gene have been reported with high genetic heterogeneity, being most mutations private found in only one family. The disease is panethnic, and estimates of incidence range from about 1 in 40,000 to 60,000 males. Our objective was to describe the analysis of 6 male and 7 female individuals belonging to 4 different Fabry disease families by automated sequencing of the seven exons of the a-galactosidase gene. Sequencing was performed using PCR fragments for each exon amplified from DNA extracted from peripheral blood. Three known mutations and one previously described in another Brazilian family were detected. Of 7 female relatives studied, 4 were carriers. Although the present study confirms the heterogeneity of mutations in Fabry disease, the finding of the same mutation previously detected in another Fabry family from our region raises the possibility of some founder effect, or genetic drift. Finally, the present study highlights the importance of molecular analysis for carrier detection and genetic counseling.

Córnea verticilata - marcador clínico da doença de Fabry: relato de caso / Cornea verticillata - a clinical marker of Fabry disease: case report

A doença de Fabry é erro inato do metabolismo dos glicoesfingolipídeos (GL), resultante da atividade deficiente da enzima alfa-galactosidase A (a-Gal), com herança ligada ao cromossomo X. O acúmulo progressivo de GL nos tecidos resulta nas manifestações clínicas da doença, mais evidentes em homens hemizigotos, e incluem angioqueratomas, acroparestesias, córnea verticilata, hipo-hidrose, envolvimento cardíaco, renal e manifestações cerebrovasculares. Foi realizada avaliação em família acometida pela doença, sendo dois pacientes do sexo feminino e três do sexo masculino. Todos os pacientes foram submetidos a anamnese, exame oftalmológico completo e dosagem da atividade da enzima a-Gal. O único achado clínico presente em todos foi a córnea verticilata. Isto demonstra o importante papel que o exame oftalmológico apresenta no diagnóstico da doença, já que as alterações oculares são tão características.

Fabry's disease is a rare X-linked lisosomal storage disorder of glycosphingolipid (GL) metabolism, caused by a deficiency of alpha-galactosidase A activity. The progressive accumulation of GL in tissues results in the clinical manifestations of the disease, that are more evident in hemizygous males, and include angiokeratomas, acroparesthesia, cornea verticillata, cardiac and kidney involvement, cerebrovascular manifestations. A family with Fabry's disease including 2 female patients and 3 male patients is reported. The patients were submitted to complete medical history, ophthalmological examination and alpha-galactosidase activity test. Cornea verticillata was a constant finding in all patients. This demonstrates the important role of the ophtalmological examination for the diagnosis of Fabry's disease since the eye findings are so characteristic of the disease.

Fabry's disease in a female carrier with bilateral thalamic infarcts: a case report ans a family study

Relata-se o caso de uma jovem, heterozigota para doença de Fabry, que desenvolveu infartos talâmicos bilaterais por oclusäo de vasos do sistema nervoso central. Três outros membros de sua família foram também avaliados. A doença de Fabry inclui-se entre as causas raras de acidente vascular cerebral em adultos jovens

Angioqueratoma corporis diffusum por deficiencia de Alfa Galactosidasa "A" / Angiokeratoma corporis diffusum due to alpha-galactosidase \"A\" defficiency

Se comunica el caso de un paciente de sexo masculino de 24 años de edad, que presenta angioqueratomas múltiples en todo el tegumento y mucosas, con afectación oftalmológica típica. Se realizó ultramicroscopía de una lesión de piel, donde pudieron verse inclusiones citoplasmáticas en células endoteliales, fibroblastos, células periteliales y perineurales. Bioquímicamente se comprobó la deficiencia enzimática en plasma de la * galactosidasa "A". Se realiza una revisión histórica y se consideran además los aspectos clínicos, histopatológicos, ultramicroscópicos y enzimáticos, como así los distintos diagnósticos diferenciales. También se dan algunas pautas terapéuticas novedosas y otras paliativas. Para finalizar, sugerimos el estudio genético de los familiares directos del paciente para detectar posibles futuros casos y poder brindarles consejo genético adecuado

Enfermedad de Fabry: a propósito de una familia / Fabry's disease: a propos of a family

Se describe una paciente de 18 años de edad quien presentó manifestaciones clínicas, bioquímicas e histopatológicas compatibles con la enfermedad de Fabry. La madre y una hermana menor, clínicamente asintomáticas, presentaron niveles enzimáticos que permitieron considerarlas como portadoras; en cambio, la determinación enzimática en el padre y en dos hermanos varones, se relacionó con la ausencia de sintomatología en estos individuos. Se discute la importancia de establecer un diagnóstico de certeza y del estudio familiar, con el fin de poder ofrecer un mejor asesoramiento genético