RESUMO
Despite the adenoids are regularly removed in patients with mucopolysaccharidoses (MPS), the underlying tissue and cellular pathologies remain understudied. We characterized an (immuno)histopathologic and ultrastructural phenotype dominated by lysosomal storage changes in a specific subset of adenotonsillar paracortical cells in 8 MPS patients (3 MPS I, 3 MPS II, and 2 MPS IIIA). These abnormal cells were effectively detected by an antibody targeting the lysosomal membrane tetraspanin CD63. Important, CD63+ storage vacuoles in these cells lacked the monocytes/macrophages lysosomal marker CD68. Such a distinct patterning of CD63 and CD68 was not present in a patient with infantile neurovisceral variant of acid sphingomyelinase deficiency. The CD63+ storage pathology was absent in two MPS I patients who either received enzyme-replacement therapy or underwent hematopoietic stem cells transplantation prior the adenoidectomy. Our study demonstrates novel features of lysosomal storage patterning and suggests diagnostic utility of CD63 detection in adenotonsillar lymphoid tissue of MPS patients.
Assuntos
Mucopolissacaridoses , Humanos , Mucopolissacaridoses/diagnóstico , Mucopolissacaridoses/tratamento farmacológico , Mucopolissacaridoses/genética , Tecido Linfoide/patologia , Lisossomos , Terapia de Reposição de Enzimas , Tetraspanina 30RESUMO
Sporadic cases of apolipoprotein A-IV medullary amyloidosis have been reported. Here we describe five families found to have autosomal dominant medullary amyloidosis due to two different pathogenic APOA4 variants. A large family with autosomal dominant chronic kidney disease (CKD) and bland urinary sediment underwent whole genome sequencing with identification of a chr11:116692578 G>C (hg19) variant encoding the missense mutation p.L66V of the ApoA4 protein. We identified two other distantly related families from our registry with the same variant and two other distantly related families with a chr11:116693454 C>T (hg19) variant encoding the missense mutation p.D33N. Both mutations are unique to affected families, evolutionarily conserved and predicted to expand the amyloidogenic hotspot in the ApoA4 structure. Clinically affected individuals suffered from CKD with a bland urinary sediment and a mean age for kidney failure of 64.5 years. Genotyping identified 48 genetically affected individuals; 44 individuals had an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73 m2, including all 25 individuals with kidney failure. Significantly, 11 of 14 genetically unaffected individuals had an eGFR over 60 ml/min/1.73 m2. Fifteen genetically affected individuals presented with higher plasma ApoA4 concentrations. Kidney pathologic specimens from four individuals revealed amyloid deposits limited to the medulla, with the mutated ApoA4 identified by mass-spectrometry as the predominant amyloid constituent in all three available biopsies. Thus, ApoA4 mutations can cause autosomal dominant medullary amyloidosis, with marked amyloid deposition limited to the kidney medulla and presenting with autosomal dominant CKD with a bland urinary sediment. Diagnosis relies on a careful family history, APOA4 sequencing and pathologic studies.
Assuntos
Amiloidose , Apolipoproteínas A , Nefrite Intersticial , Insuficiência Renal Crônica , Humanos , Pessoa de Meia-Idade , Nefrite Intersticial/diagnóstico , Nefrite Intersticial/genética , Nefrite Intersticial/complicações , Mutação , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/complicaçõesRESUMO
Mucopolysaccharidosis type VII (MPS VII) is a rare autosomal recessive lysosomal storage disorder. MPS VII is caused by mutations in the GUSB gene that encodes ß-glucuronidase. Adult MPS VII patients present with musculoskeletal abnormalities, coarse features, and corneal clouding. Cardiac and valvular impairment are common; however, severe valvular disease necessitating surgery has not yet been reported. We present a 32-year-old male MPS VII patient admitted to our hospital with decompensated heart failure. We identified aortic valve disease with severe stenosis (valve area 0.69 cm2) and moderate regurgitation. Severe mitral valve stenosis (valve area 1 cm2) with moderate to severe regurgitation was also found in the patient. In addition, an occlusion of the right coronary artery (RCA) was documented. The patient underwent surgical replacement of the mitral and aortic valves with mechanical prostheses and implantation of a venous bypass graft to his RCA. The surgery led to a significant improvement of his clinical symptoms. Six months after the procedure, both mechanical valves function normally. Histopathological assessment identified chronic inflammatory infiltrates, fibrosis and calcifications in both resected valves. Foamy cytoplasmic transformation was most evident in the valvular interstitial cells. The ultrastructural vacuolar abnormality seen in these cells corresponded to storage changes observed in other MPSs. In conclusion, we describe clinical findings and valvular pathology in an MPS VII patient with the first-reported successful combined surgical valve replacement and myocardial revascularization. The histological and ultrastructural analyses revealed that the lysosomal storage predominantly affected the valvular interstitial cells.
Assuntos
Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Ponte de Artéria Coronária , Oclusão Coronária/cirurgia , Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral/cirurgia , Estenose da Valva Mitral/cirurgia , Mucopolissacaridose VII/complicações , Adulto , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/etiologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/etiologia , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/etiologia , Humanos , Masculino , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Estenose da Valva Mitral/diagnóstico por imagem , Estenose da Valva Mitral/etiologia , Mucopolissacaridose VII/diagnóstico , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disorder categorized into 3 phenotypic variants: infantile, juvenile, and adult. Four recent reports have linked NIID to CGG expansions in the NOTCH2NLC gene in adult NIID (aNIID) and several juvenile patients. Infantile NIID (iNIID) is an extremely rare neuropediatric condition. We present a 7-year-old male patient with severe progressive neurodegenerative disease that included cerebellar symptoms with cerebellar atrophy on brain MRI, psychomotor developmental regression, pseudobulbar syndrome, and polyneuropathy. The diagnosis of iNIID was established through a postmortem neuropathology work-up. We performed long-read sequencing of the critical NOTCH2NLC repeat motif and found no expansion in the patient. We also re-evaluated an antemortem skin biopsy that was collected when the patient was 2 years and 8 months old and did not identify the intranuclear inclusions. In our report, we highlight that the 2 methods (skin biopsy and CGG expansion testing in NOTCH2NLC) used to identify aNIID patients may provide negative results in iNIID patients.
Assuntos
Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Receptor Notch2/genética , Biópsia , Encéfalo/patologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/patologia , Masculino , Pele/patologia , Medula Espinal/patologia , Repetições de Trinucleotídeos/genéticaRESUMO
Classical homocystinuria (HCU) is an inborn error of metabolism caused by loss of cystathionine ß-synthase (CBS) activity with the concomitant buildup of homocysteine. In knockout (KO) mice, a mouse model of HCU, complete lack of CBS is neonatally lethal. Administration of OT-58, an enzyme therapy for HCU, during the first 5 weeks of life rescued KO mice survival by preventing liver disease. Here, we studied the impact of a long-term uninterrupted OT-58 treatment or its absence beyond the neonatal period on liver pathology and metabolism. Plasma and liver metabolites of KO mice on OT-58 treatment were substantially improved or normalized compared with those receiving vehicle. Increased plasma activities of alanine aminotransferase and aspartate aminotransferase of vehicle-injected KO mice suggested the progression of liver damage with age and lack of treatment. At 3 months of age, liver histology showed no signs of hepatopathy in both vehicle- and OT-58-treated KO mice. However, moderate to severe liver disease, characterized by steatosis, hepatocellular necroses, disorganized endoplasmic reticulum, and swollen mitochondria, developed in 6-month-old vehicle-injected KO mice. KO mice on OT-58 treatment remained asymptomatic and were indistinguishable from age-matched healthy controls. Long-term uninterrupted OT-58 treatment was essential to prevent severe liver disease in the KO mouse model of HCU.
Assuntos
Terapia de Reposição de Enzimas , Homocistinúria/tratamento farmacológico , Hepatopatias/prevenção & controle , Animais , Modelos Animais de Doenças , Feminino , Fígado/patologia , Masculino , Camundongos , Camundongos KnockoutRESUMO
Adult-onset neuronal ceroid lipofuscinoses (ANCL, Kufs disease) are rare hereditary neuropsychiatric disorders characterized by intralysosomal accumulation of ceroid in tissues. The ceroid accumulation primarily affects the brain, leading to neuronal loss and progressive neurodegeneration. Although several causative genes have been identified (DNAJC5, CLN6, CTSF, GRN, CLN1, CLN5, ATP13A2), the genetic underpinnings of ANCL in some families remain unknown. Here we report one family with autosomal dominant (AD) Kufs disease caused by a 30 bp in-frame duplication in DNAJC5, encoding the cysteine-string protein alpha (CSPα). This variant leads to a duplication of the central core motif of the cysteine-string domain of CSPα and affects palmitoylation-dependent CSPα sorting in cultured neuronal cells similarly to two previously described CSPα variants, p.(Leu115Arg) and p.(Leu116del). Interestingly, the duplication was not detected initially by standard Sanger sequencing due to a preferential PCR amplification of the shorter wild-type allele and allelic dropout of the mutated DNAJC5 allele. It was also missed by subsequent whole-exome sequencing (WES). Its identification was facilitated by reanalysis of original WES data and modification of the PCR and Sanger sequencing protocols. Independently occurring variants in the genomic sequence of DNAJC5 encoding the cysteine-string domain of CSPα suggest that this region may be more prone to DNA replication errors and that insertions or duplications within this domain should be considered in unsolved ANCL cases.
Assuntos
Duplicação Gênica , Proteínas de Choque Térmico HSP40/genética , Proteínas de Membrana/genética , Lipofuscinoses Ceroides Neuronais/genética , Adulto , Animais , Linhagem Celular , Reações Falso-Negativas , Feminino , Testes Genéticos/normas , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Pessoa de Meia-Idade , Lipofuscinoses Ceroides Neuronais/patologia , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , Transporte Proteico , Sequenciamento Completo do Genoma/normasRESUMO
BACKGROUND: Autosomal dominant tubulointerstitial kidney disease caused by mucin-1 gene (MUC1) mutations (ADTKD-MUC1) is characterized by progressive kidney failure. Genetic evaluation for ADTKD-MUC1 specifically tests for a cytosine duplication that creates a unique frameshift protein (MUC1fs). Our goal was to develop immunohistochemical methods to detect the MUC1fs created by the cytosine duplication and, possibly, by other similar frameshift mutations and to identify novel MUC1 mutations in individuals with positive immunohistochemical staining for the MUC1fs protein. METHODS: We performed MUC1fs immunostaining on urinary cell smears and various tissues from ADTKD-MUC1-positive and -negative controls as well as in individuals from 37 ADTKD families that were negative for mutations in known ADTKD genes. We used novel analytic methods to identify MUC1 frameshift mutations. RESULTS: After technique refinement, the sensitivity and specificity for MUC1fs immunostaining of urinary cell smears were 94.2% and 88.6%, respectively. Further genetic testing on 17 families with positive MUC1fs immunostaining revealed six families with five novel MUC1 frameshift mutations that all predict production of the identical MUC1fs protein. CONCLUSIONS: We developed a noninvasive immunohistochemical method to detect MUC1fs that, after further validation, may be useful in the future for diagnostic testing. Production of the MUC1fs protein may be central to the pathogenesis of ADTKD-MUC1.
Assuntos
Predisposição Genética para Doença/epidemiologia , Mucina-1/genética , Rim Policístico Autossômico Dominante/genética , Rim Policístico Autossômico Dominante/patologia , Biópsia por Agulha , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Incidência , Masculino , Mutação/genética , Linhagem , Rim Policístico Autossômico Dominante/mortalidade , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Medição de RiscoRESUMO
Mucopolysaccharidosis type IVB (MPS IVB) is a very rare lysosomal storage disorder characterized by skeletal dysplasia, hearing disorder, and cardiac valvular disease. Herein, we report an extremely rare manifestation of MPS IVB in a 60-year-old female patient who underwent a successful aortic valve replacement. The patient presented with mild coarse facial features, short stature, mild dyspnea, sternal protrusion, mild lumbar hyperlordosis, and waddling gait owing to bilateral femoral head necroses and bilateral arthrosis of the knees. The patient also suffered from dyspnea, NYHA II-III. Echocardiography revealed severe stenosis of a calcified aortic valve (AVA 0.67 cm2, AVAi 0.45â¯cm2/m2, PG max/mean 130/80â¯mmHg), left ventricular hypertrophy with predominant septal thickening (18â¯mm) and mild left ventricle outflow tract obstruction at rest, mild mitral valve regurgitation, and dilated ascending aorta (36 mm, 26.5â¯mm/m2). Dyspnea resolved after septal myectomy and replacement of the aortic valve with bioprosthesis. Excretion levels and spectrum of glycosaminoglycans (GAGs) in urine were normal in the patient. We confirmed the diagnosis of MPS IVB by identifying decreased beta-galactosidase activity in isolated leukocytes (6â¯nmol/h/mg; controls 95-272) and by molecular genetic analyses (c.438_440delTCT and c.817_818TG>CT mutations in the GLB1 gene). Primary lysosomal storage of glycosaminoglycans was detected in fibroblasts of the aortic valve. Additional pathologies included valvular fibrosis, calcification, neovascularization, and mild chronic inflammation. In conclusion, the diagnosis of MPS IVB should be considered in older patients with cardiac valvular disease and progressive skeletal abnormality even if urinary excretion levels of GAGs are normal.
Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/patologia , Valva Aórtica/transplante , Calcinose/cirurgia , Implante de Prótese de Valva Cardíaca , Mucopolissacaridose IV/diagnóstico , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/etiologia , Estenose da Valva Aórtica/fisiopatologia , Bioprótese , Biópsia , Calcinose/diagnóstico por imagem , Calcinose/etiologia , Calcinose/fisiopatologia , Análise Mutacional de DNA , Diagnóstico Tardio , Ecocardiografia , Feminino , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/instrumentação , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Mucopolissacaridose IV/complicações , Mucopolissacaridose IV/genética , Mutação , Fatores de Tempo , Resultado do Tratamento , beta-Galactosidase/genéticaRESUMO
Blood group B glycosphingolipids (B-GSLs) are substrates of the lysosomal alpha-galactosidase A (AGAL). Similar to its major substrate-globotriaosylceramide (Gb3Cer)-B-GSLs are not degraded and accumulate in the cells of patients affected by an inherited defect of AGAL activity (Fabry disease-FD).The pancreas is a secretory organ known to have high biosynthesis of blood group GSLs. Herein, we provide a comprehensive overview of the biochemical and structural abnormalities in pancreatic tissue from two male FD patients with blood group B. In both patients, we found major accumulation of a variety of complex B-GSLs carrying predominantly hexa- and hepta-saccharide structures. The subcellular pathology was dominated by deposits containing B-glycoconjugates and autofluorescent ceroid. The contribution of Gb3Cer to the storage was minor. This abnormal storage pattern was specific for the pancreatic acinar epithelial cells. Other pancreatic cell types including those of islets of Langerhans were affected much less or not at all.Altogether, we provide evidence for a key role of B-antigens in the biochemical and morphological pathology of the exocrine pancreas in FD patients with blood group B. We believe that our findings will trigger further studies aimed at assessing the potential pancreatic dysfunction in this disease.
Assuntos
Doença de Fabry/metabolismo , Glicoesfingolipídeos/metabolismo , Pâncreas/metabolismo , Sistema ABO de Grupos Sanguíneos/metabolismo , Células Acinares/metabolismo , Células Acinares/ultraestrutura , Estudos de Casos e Controles , Doença de Fabry/sangue , Doença de Fabry/patologia , Galactose/análise , Galactose/metabolismo , Glicoesfingolipídeos/química , Humanos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/ultraestrutura , Masculino , Pessoa de Meia-Idade , Pâncreas/ultraestruturaRESUMO
BACKGROUND: The progressive myoclonic epilepsies (PME) are a heterogeneous group of disorders in which a specific diagnosis cannot be made in a subset of patients, despite exhaustive investigation. C9orf72 repeat expansions are emerging as an important causal factor in several adult-onset neurodegenerative disorders, in particular frontotemporal lobar degeneration and amyotrophic lateral sclerosis. An association with PME has not been reported previously. OBJECTIVE: To identify the causative mutation in a Belgian family where the proband had genetically unexplained PME. RESULTS: We report a 33-year old woman who had epilepsy since the age of 15 and then developed progressive cognitive deterioration and multifocal myoclonus at the age of 18. The family history suggested autosomal dominant inheritance of psychiatric disorders, epilepsy, and dementia. Thorough workup for PME including whole exome sequencing did not reveal an underlying cause, but a C9orf72 repeat expansion was found in our patient and affected relatives. Brain biopsy confirmed the presence of characteristic p62-positive neuronal cytoplasmic inclusions. CONCLUSION: C9orf72 mutation analysis should be considered in patients with PME and psychiatric disorders or dementia, even when the onset is in late childhood or adolescence.
Assuntos
Proteína C9orf72/genética , Expansão das Repetições de DNA , Epilepsias Mioclônicas Progressivas/genética , Adulto , Idade de Início , Encéfalo/patologia , Família , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Epilepsias Mioclônicas Progressivas/patologia , Epilepsias Mioclônicas Progressivas/fisiopatologia , Epilepsias Mioclônicas Progressivas/psicologia , Linhagem , FenótipoRESUMO
Mucin 1 kidney disease, previously referred to as medullary cystic kidney disease type 1, is a rare hereditary kidney disease. It is one of several diseases now termed autosomal dominant tubulointerstitial kidney disease, as proposed by a KDIGO (Kidney Disease: Improving Global Outcomes) consensus report in 2014. Autosomal dominant tubulointerstitial kidney diseases share common clinical findings, such as autosomal dominant inheritance, bland urinary sediment, absent to mild proteinuria, and progressive loss of kidney function. Although the pathophysiology of mucin 1 kidney disease is still under investigation, genetic testing has been developed to detect the most well-known mutation, a single cytosine insertion into a string of 7 cytosines in the variable-number tandem repeat (VNTR) region of the MUC-1 gene. With this diagnostic tool, nephrologists can offer genetic counseling to affected families and monitor closely for progression of disease. We report a Hispanic patient with a strong family history of chronic kidney disease who tested positive for the MUC1 mutation.
Assuntos
DNA/genética , Rim/patologia , Mucina-1/genética , Mutação , Rim Policístico Autossômico Dominante/genética , Adulto , Biópsia , Análise Mutacional de DNA , Feminino , Humanos , Mucina-1/metabolismo , Rim Policístico Autossômico Dominante/diagnóstico , Rim Policístico Autossômico Dominante/metabolismo , UltrassonografiaRESUMO
Classical homocystinuria (HCU) is an inborn error of sulfur amino acid metabolism caused by deficient activity of cystathionine ß-synthase (CBS), resulting in an accumulation of homocysteine and a concomitant decrease of cystathionine and cysteine in blood and tissues. In mice, the complete lack of CBS is neonatally lethal. In this study, newborn CBS-knockout (KO) mice were treated with recombinant polyethyleneglycolylated human truncated CBS (PEG-CBS). Full survival of the treated KO mice, along with a positive impact on metabolite levels in plasma, liver, brain, and kidneys, was observed. The PEG-CBS treatment prevented an otherwise fatal liver disease characterized by steatosis, death of hepatocytes, and ultrastructural abnormalities of endoplasmic reticulum and mitochondria. Furthermore, treatment of the KO mice for 5 mo maintained the plasma metabolite balance and completely prevented osteoporosis and changes in body composition that characterize both the KO model and human patients. These findings argue that early treatment of patients with HCU with PEG-CBS may prevent clinical symptoms of the disease possibly without the need of dietary protein restriction.-Majtan, T., Hulková, H., Park, I., Krijt, J., Kozich, V., Bublil, E. M., Kraus, J. P. Enzyme replacement prevents neonatal death, liver damage, and osteoporosis in murine homocystinuria.
Assuntos
Cistationina beta-Sintase/metabolismo , Cistationina beta-Sintase/uso terapêutico , Fígado Gorduroso/prevenção & controle , Homocistinúria/tratamento farmacológico , Homocistinúria/enzimologia , Hepatopatias/prevenção & controle , Osteoporose/prevenção & controle , Animais , Composição Corporal/efeitos dos fármacos , Cistationina beta-Sintase/genética , Modelos Animais de Doenças , Fígado Gorduroso/enzimologia , Feminino , Homocistinúria/metabolismo , Homocistinúria/patologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Fígado/patologia , Hepatopatias/enzimologia , Masculino , Camundongos , Camundongos Knockout , Proteínas Recombinantes/uso terapêuticoRESUMO
Autosomal-dominant tubulo-interstitial kidney disease (ADTKD) encompasses a group of disorders characterized by renal tubular and interstitial abnormalities, leading to slow progressive loss of kidney function requiring dialysis and kidney transplantation. Mutations in UMOD, MUC1, and REN are responsible for many, but not all, cases of ADTKD. We report on two families with ADTKD and congenital anemia accompanied by either intrauterine growth retardation or neutropenia. Ultrasound and kidney biopsy revealed small dysplastic kidneys with cysts and tubular atrophy with secondary glomerular sclerosis, respectively. Exclusion of known ADTKD genes coupled with linkage analysis, whole-exome sequencing, and targeted re-sequencing identified heterozygous missense variants in SEC61A1-c.553A>G (p.Thr185Ala) and c.200T>G (p.Val67Gly)-both affecting functionally important and conserved residues in SEC61. Both transiently expressed SEC6A1A variants are delocalized to the Golgi, a finding confirmed in a renal biopsy from an affected individual. Suppression or CRISPR-mediated deletions of sec61al2 in zebrafish embryos induced convolution defects of the pronephric tubules but not the pronephric ducts, consistent with the tubular atrophy observed in the affected individuals. Human mRNA encoding either of the two pathogenic alleles failed to rescue this phenotype as opposed to a complete rescue by human wild-type mRNA. Taken together, these findings provide a mechanism by which mutations in SEC61A1 lead to an autosomal-dominant syndromic form of progressive chronic kidney disease. We highlight protein translocation defects across the endoplasmic reticulum membrane, the principal role of the SEC61 complex, as a contributory pathogenic mechanism for ADTKD.
Assuntos
Anemia/genética , Heterozigoto , Nefropatias/genética , Mutação , Canais de Translocação SEC/genética , Adulto , Idoso , Alelos , Sequência de Aminoácidos , Animais , Biópsia , Criança , Doença Crônica , Progressão da Doença , Retículo Endoplasmático/metabolismo , Exoma/genética , Feminino , Retardo do Crescimento Fetal/genética , Genes Dominantes , Complexo de Golgi/metabolismo , Humanos , Recém-Nascido , Nefropatias/patologia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação de Sentido Incorreto/genética , Neutropenia/genética , Linhagem , Fenótipo , RNA Mensageiro/análise , RNA Mensageiro/genética , Canais de Translocação SEC/química , Síndrome , Adulto Jovem , Peixe-Zebra/embriologia , Peixe-Zebra/genéticaRESUMO
The Acadian variant of Fanconi Syndrome refers to a specific condition characterized by generalized proximal tubular dysfunction from birth, slowly progressive chronic kidney disease and pulmonary interstitial fibrosis. This condition occurs only in Acadians, a founder population in Nova Scotia, Canada. The genetic and molecular basis of this disease is unknown. We carried out whole exome and genome sequencing and found that nine affected individuals were homozygous for the ultra-rare non-coding variant chr8:96046914 T > C; rs575462405, whereas 13 healthy siblings were either heterozygotes or lacked the mutant allele. This variant is located in intron 2 of NDUFAF6 (NM_152416.3; c.298-768 T > C), 37 base pairs upstream from an alternative splicing variant in NDUFAF6 chr8:96046951 A > G; rs74395342 (c.298-731 A > G). NDUFAF6 encodes NADH:ubiquinone oxidoreductase complex assembly factor 6, also known as C8ORF38. We found that rs575462405-either alone or in combination with rs74395342-affects splicing and synthesis of NDUFAF6 isoforms. Affected kidney and lung showed specific loss of the mitochondria-located NDUFAF6 isoform and ultrastructural characteristics of mitochondrial dysfunction. Accordingly, affected tissues had defects in mitochondrial respiration and complex I biogenesis that were corrected with NDUFAF6 cDNA transfection. Our results demonstrate that the Acadian variant of Fanconi Syndrome results from mitochondrial respiratory chain complex I deficiency. This information may be used in the diagnosis and prevention of this disease in individuals and families of Acadian descent and broadens the spectrum of the clinical presentation of mitochondrial diseases, respiratory chain defects and defects of complex I specifically.
Assuntos
Complexo I de Transporte de Elétrons/genética , Síndrome de Fanconi/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Adulto , Alelos , Canadá , Mapeamento Cromossômico , Exoma/genética , Síndrome de Fanconi/patologia , Feminino , Predisposição Genética para Doença , Heterozigoto , Homozigoto , Humanos , Rim/metabolismo , Rim/patologia , Pulmão/metabolismo , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/patologia , Doenças Mitocondriais/metabolismo , Doenças Mitocondriais/patologia , MutaçãoRESUMO
Homocystinuria, which typically results from cystathionine ß-synthase (CBS) deficiency, is the most common defect of sulfur amino acid metabolism. CBS condenses homocysteine and serine to cystathionine that is then converted to cysteine. Individuals with homocystinuria have markedly elevated plasma levels of homocysteine and methionine and reduced concentrations of cystathionine and cysteine. Clinical disease manifestations include thromboembolism and neuropsychiatric, ocular, and skeletal complications. Here, we have shown that administration of PEGylated CBS into the circulation of homocystinuria model mice alters the extra- and intracellular equilibrium of sulfur amino acids, resulting in a decrease of approximately 75% in plasma total homocysteine (tHcy) and normalization of cysteine concentrations. Moreover, the decrease in homocysteine and the normalization of cysteine in PEGylated CBS-treated model mice were accompanied by improvement of histopathological liver symptoms and increased survival. Together, these data suggest that CBS enzyme replacement therapy (ERT) is a promising approach for the treatment of homocystinuria and that ERT for metabolic diseases may not necessitate introduction of the deficient enzyme into its natural intracellular compartment.
Assuntos
Cistationina beta-Sintase/deficiência , Cistationina beta-Sintase/uso terapêutico , Homocistinúria/tratamento farmacológico , Homocistinúria/metabolismo , Animais , Cistationina beta-Sintase/genética , Modelos Animais de Doenças , Homocistinúria/patologia , Humanos , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Polietilenoglicóis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapêuticoRESUMO
Fabry disease is an X-linked lysosomal storage disease due to deficient α-galactosidase A (α-Gal A) activity and the resultant lysosomal accumulation of globotriaosylceramide (Gb3) and related lipids primarily in blood vessels, kidney, heart, and other organs. The renal distribution of stored glycolipid species in the α-Gal A knockout mouse model was compared to that in mice to assess relative distribution and absolute amounts of accumulated sphingolipid isoforms. Twenty isoforms of five sphingolipid groups were visualized by mass spectrometry imaging (MSI), and their distribution was compared with immunohistochemical (IHC) staining of Gb3, the major stored glycosphingolipid in consecutive tissue sections. Quantitative bulk lipid analysis of tissue sections was assessed by electrospray ionization with tandem mass spectrometry (ESI-MS/MS). In contrast to the findings in wild-type mice, all three analytical techniques (MSI, IHC, and ESI-MS/MS) revealed increases in Gb3 isoforms and ceramide dihexosides (composed mostly of galabiosylceramides), respectively. To our knowledge, this is the first report of the distribution of individual molecular species of Gb3 and galabiosylceramides in kidney sections in Fabry disease mouse. In addition, the spatial distribution of ceramides, ceramide monohexosides, and sphingomyelin forms in renal tissue is presented and discussed in the context of their biosynthesis.
Assuntos
Doença de Fabry/metabolismo , Rim/química , Esfingolipídeos/metabolismo , Animais , Modelos Animais de Doenças , Doença de Fabry/enzimologia , Doença de Fabry/genética , Humanos , Imunoquímica , Rim/metabolismo , Espectrometria de Massas , Camundongos , Camundongos Knockout , Esfingolipídeos/química , alfa-Galactosidase/genética , alfa-Galactosidase/metabolismoRESUMO
We present a case study of an elderly woman with systemic lambda-type AL amyloidosis that featured unusually extensive cutaneous involvement. The case initially presented with a sudden hyper ß-carotenemia with carotenoderma that instigated the clinical examination including skin biopsy. A diagnosis of systemic amyloidosis was made. Immunohistochemistry and Western-blot analysis indicated the presence of lambda light chain proteins in skin amyloid deposits. However, notable co-deposition of wild-type apoA-I and transthyretin was observed which caused initial diagnostic confusion. Proteomic analysis of microdissected skin amyloid deposits by mass spectrometry confirmed lambda light chain proteins in amyloid deposits and co-deposition of apolipoprotein A-IV and serum amyloid P-component. The patient died from renal failure caused by amyloid nephropathy combined with analgesic nephropathy. The autopsy disclosed vascular, cardiac, renal and pulmonary amyloid deposition. While all amyloid deposits were positive for lambda light chain proteins, the immunodetection of apoA-I and transthyretin varied significantly among the visceral amyloid deposits. Although the patient exhibited a 1000-fold increase in serum ß-carotene levels, only a mild increase in retinol and lutein concentrations was observed. Increased ß-carotene values were also found in the liver and the skin. The mechanisms underlying this hyper ß-carotenemia remain undetermined.
Assuntos
Amiloidose/diagnóstico , Hiperpigmentação/diagnóstico , Idoso , Amiloide/metabolismo , Amiloidose/sangue , Evolução Fatal , Feminino , Humanos , Hiperpigmentação/sangue , Pigmentação da Pele , beta Caroteno/sangueRESUMO
BACKGROUND: Hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction has been associated with marked exercise intolerance and poor prognosis. However, molecular pathogenesis of this phenotype remains unexplained in a large proportion of cases. METHODS AND RESULTS: We performed whole exome sequencing as an initial genetic test in a large Czech family with 3 males affected by nonobstructive hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction in end-stage disease. A novel frameshift mutation of four-and-a-half LIM domain 1 gene (FHL1) (c.599_600insT; p.F200fs32X) was detected in these individuals. The mutation does not affect transcription, splicing, and stability of FHL1 mRNA and results in production of truncated FHL1 protein, which is contrary to heart tissue homogenate not detectable in frozen tissue sections of myocardial biopsy of affected males. The identified mutation cosegregated also with abnormal ECG and with 1 case of apical hypertrophic cardiomyopathy in heterozygous females. Although skeletal muscle involvement is a common finding in FHL1-related diseases, we could exclude myopathy in all mutation carriers. CONCLUSIONS: We identified a novel FHL1 mutation causing isolated hypertrophic cardiomyopathy with X-chromosomal inheritance.