Morphological Hallmarks of Classical Fabry Disease: An Ultrastructural Study in a Large Spanish Family.

Fabry disease (FD) is a rare lysosomal disorder caused by α-galactosidase A deficiency, and it leads to the systemic deposition of globotriasylceramide. Demonstrations of the storage material in biopsies support this diagnosis. We report a histological and ultrastructural study of biopsies that were performed on 11 individuals from a family with the variant p.Gln279Arg in GLA, which is associated with the classical phenotype of Fabry disease. Intralysosomal deposits were found in all biopsies, corresponding to the skin, kidney, and endomyocardium in both sexes and at different ages. In nine of the skin biopsies, deposits were analysed by immunofluorescence and quantified at the ultrastructural level. Then, the findings were compared according to sex, genotype, and treatment. The quantification of the deposits in the skin biopsies revealed a broader involvement in men than in women. A significant clearance of the deposits was observed in one case after treatment. Tissue involvement was remarkable at diagnosis in all individuals. The findings from the skin biopsies were demonstrative of classic FD, thus supporting the diagnosis; repeated biopsy analyses suggested the benefit of early treatment.

Therapeutic Approaches in Lysosomal Storage Diseases.

Lysosomal Storage Diseases are multisystemic disorders determined by genetic variants, which affect the proteins involved in lysosomal function and cellular metabolism. Different therapeutic approaches, which are based on the physiologic mechanisms that regulate lysosomal function, have been proposed for these diseases. Currently, enzyme replacement therapy, gene therapy, or small molecules have been approved or are under clinical development to treat lysosomal storage disorders. The present article reviews the main therapeutic strategies that have been proposed so far, highlighting possible limitations and future perspectives.

Systemic Treatment of Fabry Disease Using a Novel AAV9 Vector Expressing α-Galactosidase A.

Fabry disease is a rare X-linked disorder affecting α-galactosidase A, a rate-limiting enzyme in lysosomal catabolism of glycosphingolipids. Current treatments present important limitations, such as low half-life and limited distribution, which gene therapy can overcome. The aim of this work was to test a novel adeno-associated viral vector, serotype 9 (AAV9), ubiquitously expressing human α-galactosidase A to treat Fabry disease (scAAV9-PGK-GLA). The vector was preliminary tested in newborns of a Fabry disease mouse model. 5 months after treatment, α-galactosidase A activity was detectable in the analyzed tissues, including the central nervous system. Moreover, we tested the vector in adult animals of both sexes at two doses and disease stages (presymptomatic and symptomatic) by single intravenous injection. We found that the exogenous α-galactosidase A was active in peripheral tissues as well as the central nervous system and prevented glycosphingolipid accumulation in treated animals up to 5 months following injection. Antibodies against α-galactosidase A were produced in 9 out of 32 treated animals, although enzyme activity in tissues was not significantly affected. These results demonstrate that scAAV9-PGK-GLA can drive widespread and sustained expression of α-galactosidase A, cross the blood brain barrier after systemic delivery, and reduce pathological signs of the Fabry disease mouse model.

Clinical, pathological and genetic spectrum in 89 cases of mitochondrial progressive external ophthalmoplegia.

BACKGROUND: Mitochondrial progressive external ophthalmoplegia (PEO) encompasses a broad spectrum of clinical and genetic disorders. We describe the phenotypic subtypes of PEO and its correlation with molecular defects and propose a diagnostic algorithm. METHODS: Retrospective analysis of the clinical, pathological and genetic features of 89 cases. RESULTS: Three main phenotypes were found: 'pure PEO' (42%), consisting of isolated palpebral ptosis with ophthalmoparesis; Kearns-Sayre syndrome (10%); and 'PEO plus', which associates extraocular symptoms, distinguishing the following subtypes: : myopathic (33%), bulbar (12%) and others (3%). Muscle biopsy was the most accurate test, showing mitochondrial changes in 95%. Genetic diagnosis was achieved in 96% of the patients. Single large-scale mitochondrial DNA (mtDNA) deletion was the most frequent finding (63%), followed by multiple mtDNA deletions (26%) due to mutations in TWNK (n=8), POLG (n=7), TK2 (n=6) or RRM2B (n=2) genes, and point mtDNA mutations (7%). Three new likely pathogenic mutations were identified in the TWNK and MT-TN genes. CONCLUSIONS: Phenotype-genotype correlations cannot be brought in mitochondrial PEO. Muscle biopsy should be the first step in the diagnostic flow of PEO when mitochondrial aetiology is suspected since it also enables the study of mtDNA rearrangements. If no mtDNA deletions are identified, whole mtDNA sequencing should be performed.

Variante conductual de la demencia frontotemporal como forma de presentación de la degeneración corticobasal / Behavioural variant of frontotemporal dementia as the presenting symptom of corticobasal degeneration

Introducción. La variante conductual de la demencia frontotemporal se caracteriza por el deterioro progresivo de la personalidad, social y cognitivo que se asocia con diversas patologías moleculares de la degeneración lobar frontotemporal (DLFT): DLFT-tau, DLFT-TDP y DLFT-FUS. El estudio anatomopatológico es necesario para su diagnóstico. Caso clínico. Varón de 61 años, con un cuadro progresivo de tres años de evolución de trastorno conductual, apatía, lenguaje pobre, perseveración, falta de empatía, bulimia y disfunción ejecutiva. En la neuroimagen se objetivó una atrofia cortical frontal de predominio derecho, y en la tomografía simple por emisión de fotón único cerebral, una hipoperfusión frontoparietotemporal bilateral con afectación de tálamos y caudados. Clínicamente, se le diagnosticó probable demencia frontotemporal, variante conductual. Tras su fallecimiento, se donó el cerebro al Banco de Tejidos Neurológicos y el diagnóstico neuropatológico fue el de degeneración corticobasal. Conclusiones. La degeneración corticobasal es una de las taupatías de la DLFT-tau. Los criterios diagnósticos de degeneración corticobasal de 2013 contemplan como fenotipo clínico la disfunción ejecutiva, las alteraciones conductuales y de personalidad similar al de este paciente. El caso anatomoclínico presentado ilustra la falta de correlación entre el fenotipo clínico y el diagnóstico neuropatológico subyacente en la demencia frontotemporal, y la necesidad de realizar el estudio histopatológico para llegar al diagnóstico definitivo

Introduction. The behavioural variant of frontotemporal dementia is characterised by progressive social, cognitive and personality deterioration associated with several molecular pathologies of frontotemporal lobar dementia (FTLD): FTLD-tau, FTLD-TDP and FTLD-FUS. Its diagnosis requires pathological studies. Case report. A 61-year-old male, with a three-year progressive history of behavioural disorder, apathy, poor language skills, perseveration, lack of empathy, bulimia and executive dysfunction. Neuroimaging revealed right-dominant frontal cortical atrophy, and a single-photon emission tomography brain scan showed bilateral frontal hypoperfusion with thalamic and caudate involvement. Clinically, he was diagnosed with probable frontotemporal dementia, behavioural variant. On his death, his brain was donated to the Neurological Tissue Bank and the neuropathological diagnosis was corticobasal degeneration. Conclusions. Corticobasal degeneration is one of the FTLD-tau tauopathies. The 2013 diagnostic criteria for corticobasal degeneration include executive dysfunction and behavioural and personality disorders similar to those of this patient as a clinical phenotype. The anatomoclinical case presented illustrates the absence of any correlation between the clinical phenotype and the underlying neuropathological diagnosis in frontotemporal dementia, and the need to conduct a histopathological study in order to reach a definitive diagnosis

Enfermedad de McArdle: presentación de 2 casos clínicos / McArdle disease: 2 case reports

El estudio del incremento de la creatinina fosfoquinasa (CPK) constituye un motivo de consulta frecuente en diversas especialidades médicas. Entre las enfermedades que cursan con CPK alta se encuentran las miopatías metabólicas siendo la enfermedad de McArdle la glucogenosis muscular más frecuente. Presentamos 2 casos clínicos de pacientes derivados a nuestro servicio de reumatología para estudio de CPK elevada cuyo diagnóstico final fue enfermedad de McArdle: un hombre de 72 años, asintomático desde el punto de vista muscular, en el que se objetivó de manera casual elevación importante de CPK en una analítica de rutina y una mujer de 30 años con síntomas musculares muy leves. El electromiograma (EMG) fue normal en ambos pacientes. En ninguno de los 2 casos existía actividad de la miofosforilasa en la biopsia muscular, siendo diagnosticados de enfermedad de McArdle (AU)

A high serum level of creatine kinase (CK) is a common reason for referring to medical specialities. Myopathies are one of the causes of elevated levels of CK. McArdle disease is the most common disorder of skeletal muscle carbohydrate metabolism. The cases are presented on 2 patients who were referred to our medical consultation to study the cause of their increased CK levels: a 72 year old asymptomatic man with high levels of CK detected by chance in a routine analysis, and a 30 year old woman with very few symptoms, apart from slight muscle pain and tiredness. Electromyography was normal in both patients. There was null activity of myophosphorylase in muscle biopsy of both cases, so a diagnosis of McArdle disease was made (AU)

McArdle disease: 2 case reports. / Enfermedad de McArdle: presentación de 2 casos clínicos.

A high serum level of creatine kinase (CK) is a common reason for referring to medical specialities. Myopathies are one of the causes of elevated levels of CK. McArdle disease is the most common disorder of skeletal muscle carbohydrate metabolism. The cases are presented on 2 patients who were referred to our medical consultation to study the cause of their increased CK levels: a 72 year old asymptomatic man with high levels of CK detected by chance in a routine analysis, and a 30 year old woman with very few symptoms, apart from slight muscle pain and tiredness. Electromyography was normal in both patients. There was null activity of myophosphorylase in muscle biopsy of both cases, so a diagnosis of McArdle disease was made.

Nódulos subcutáneos como forma de presentación aguda de sarcoidosis / Subcutaneous nodules as acute onset of sarcoidosis

La sarcoidosis es una enfermedad granulomatosa, multisistémicade etiología desconocida. Su diagnóstico es deexclusión, una vez descartadas infecciones y otras causas.Puede afectar a cualquier órgano, pero más frecuentemente apulmones y ganglios linfáticos. La piel está afectada en un25% de los casos. Su presentación como nódulos subcutáneoses rara y han sido descritos muy pocos casos de sarcoidosissubcutánea como manifestación inicial de la enfermedad.Presentamos el caso de una mujer de 27 años con unnódulo supraciliar palpable, firme e indoloro, de meses deevolución, revestido de piel normal, como único dato clínicode interés. Recidivó varias veces. La extirpación de lalesión y su posterior estudio histológico mostró granulomasno necrotizantes situados en dermis profunda e hipodermis.Las tinciones realizas para demostrar hongos, bacilos ácidoalcoholresistentes o materiales extraños resultaron negativas.Todas las exploraciones complementarias a las que fuesometida la paciente resultaron normales.Se administró tratamiento corticoesteroideo, al que respondiófavorablemente.Destacamos que la sarcoidosis debe ser considerada enel diagnóstico diferencial de enfermedades que debutan connódulos subcutáneos y así evitar exploraciones más agresivaspara su diagnóstico

Sarcoidosis is a multisystemic disease of unknown etiology.Diagnosis is made after exclusion of other granulomatousand infectious diseases.Any organ can be involved, most commonly lungs andskin. On average, 25% of sarcoidosis cases have cutaneousinvolvement. Subcutaneous nodules at the onset of the diseaseare extremely infrequent.We report the case of a 27 year-old woman who presentedwith a firm, painless subcutaneous nodule on the forehead,without involvement of the overlying skin. The lesionwas removed and relapsed several times later.Histologic examination revealed noncaseating granulomasin subcutaneous tissue and deep dermis. Special stainsfor fungi, acid-fast bacilli or foreign body material, were allnegative.Despite thorough investigations, all tests were negativeand the patient didn’t have any evidence of extra-cutaneoussarcoidosis. She started on oral corticosteroids, inducing agood response.We highlight the importance of an exhaustive study ofevery single subcutaneous nodule in order to avoid a delayin the diagnosis of sarcoidosis and the unnecessary use ofmore aggressive methods