Browsing by Author "Nogueira, Célia"
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- Adult-onset form in VLCAD deficiency: seven casesPublication . Sousa, Carmen; Marcão, Ana; Nogueira, Célia; Fonseca, Helena; Rocha, Hugo; Silva, Carla; Guimas, Arlindo; Evangelista, Teresinha; Maré, Rui; Vilarinho, LauraVery long chain acyl-Co-A dehydrogenase deficiency (VLCADD, MIM 201475) is an autosomal recessive disorder characterized by impaired mitochondrial β-oxidation of fatty acids with a chain length between 14 and 18 carbons. The prevalence of VLCAD deficiency in Portugal is 1/101,613. VLCADD has three forms of clinical presentation: severe early-onset; intermediate with childhood onset and adult-onset, of mild severity, characterized by exercise intolerance, myalgia and recurrent episodes of rhabdomyolysis. The development of electrospray ionization tandem mass spectrometry (MS/MS) has allowed beyond the screening of neonatal forms a marked improvement on diagnosis of the adult onset form. The authors report the acyl-carnitines profile that revealed accumulation of tetradecenoyl carnitine (C14:1) in seven individuals with clinical symptoms with the ages between 11 and 63. The eldest patient was diagnosed at the age of 63 years. These results were confirmed by molecular ACADVL gene analysis. When rhabdomyolysis is present in a patient, and after differential diagnosis, it is important to consider the possibility of a VLCAD deficiency. This late-onset form may be undetectable by acyl-carnitine profile in asymptomatic period, and only in crisis is informative. However, if VLCADD is considered the molecular analysis of ACADVL should be performed in all suspected cases.
- Alterations in lipid profile and enzymes paraoxonase and butyrylcholinesterase in CBS-deficient patientsPublication . Vanzin, Camila; Nogueira, Célia; Vilarinho, Laura; Wajner, Moacir; Wyse, Angela; Vargas, CarmenHomocystinuria is an inborn error of metabolism most frequently caused by cystathionine β-synthase (CBS) deficiency. Homocysteine (Hcy), methionine (Met) and other metabolites of Hcy accumulate in the body of affected patients, leading to clinical manifestations such as dislocation of the optic lents, osteoporosis, mental retardation, and thromboembolism. Despite the fact that thromboembolism represent the major cause of morbidity and the most frequent cause of death in CBS-deficient patients, the cause of cardiovascular changes found in homocystinuria remain unclear. In this work, we evaluated the lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, oxidized LDL cholesterol, apolipoprotein A-1) and the activities of the enzymes paraoxonase (PON1) and butyrylcholinesterase (BuChE) in plasma of patients with homocystinuria due CBS deficiency, at diagnosis and during the treatment. It was verified a significant decrease in HDL cholesterol and apolipoprotein A1 levels in the both groups of CBS-deficient patients (at diagnosis and under treatment) when compared to controls. PON1 activity was also significantly lower in the both groups of CBS-deficient patients when compared to controls which may be related with an Hcy-dependent oxidation of any group important to catalytic activity of the enzyme that favors the atherogenesis. BuChE activity was significantly increased only in CBS-deficient patients at diagnosis and it is known that this enzymatic activity is positively associated with cardiovascular risk factors. Evaluated together, our results demonstrated that treated or not CBS-deficient patients presented important alterations in lipid metabolism. This work contributes to the understanding of the responsible mechanisms of vascular lesions in CBS-deficient patients.
- Autosomal Recessive Cerebellar Ataxia and Low Mitocondrial Complex III in a Portuguese FamilyPublication . Nogueira, Célia; Nesti, Claudia; Meschini, Maria Chiara; Carrozzo, Rosalba; Barros, Jose; Sá, Maria José; Azevedo, Luisa; Vilarinho, Laura; Santorelli, FilippoIntroduction: Defects of mitochondrial complex III (CIII) are a relatively rare cause of mitochondrial dysfunction. The complex catalyzes the electron transfer from reduced coenzyme Q to cytochrome c and is composed of 11 subunits, one of which (MT-CYB) is mtDNA encoded. Mutations in MT-CYB and in assembly factor BCS1L account for the vast majority of cases with low CIII, and are associated with a wide range of neurological disorders. The gene coding for human tetratricopeptide 19 (TTC19) produces a poorly characterized protein thought to be involved in the correct assembly of CIII. Recently, mutations in TTC19 have been described in three unrelated Italian kindred in association with a severe neurodegenerative disease. Objectives: We studied a consanguineous Portuguese family where a severe neurometabolic disorder occurred in four siblings (three men and one woman) in association with a slowly progressive disorder characterized by dystonia of hands and feet, ataxic gait, severe olivo-ponto-cerebellar atrophy documented at brain MRI, and relentless psychiatric manifestations. Variability in age at onset and disease course was observed. Methods: The enzymatic activity of CIII was determined in muscle using a reported spectrophotometric method. Sequence analysis of genomic DNA was performed to identify disease-causing mutations in TTC19. Immunodetection analysis in muscle homogenate and skin fibroblasts allowed the detection of the amount TTC19 protein using a commercially available anti-TTC19 antibody. Results: In this family, we identified a novel homozygous TTC19 mutation predicting frameshift and early protein truncation. The mutation was heterozygous in parents and healthy siblings, and it was absent in ethnically-matched controls. The protein was undetectable in tissues by Western blot analyses. Conclusion: This is the fourth kindred presenting mutations in TTC19. The clinical phenotype of such condition is severe, embraces neurological and psychiatric symptoms, and represents a further example of autosomal recessive ataxia of metabolic origin.
- Bases moleculares de los defectos en el complejo mitocondrial ETF/ETF-QOPublication . Rocha, Hugo; Nogueira, Célia; Martins, Esmeralda; Rodrigues, Esmeralda; Leão, Miguel; Sousa, Carmen; Fonseca, Helena; Marcão, Ana; Gaspar, Ana; Brandão, Otilia; Santos, Helena; Coelho, Teresa; Ribeiro, J. Miguel; Vilarinho, LauraDefectos en el complejo mitocondrial ETF/ETF-QO (ETF - flavoproteína transferidora de electrones; ETFQO - flavoproteína transferidora de electrones ubiquinona oxidorreductasa), resultan en la disfunción secundaria de 11 deshidrogenasas que utilizan este complejo para transferir los electrones a la cadena de transporte electrónico, bloqueando la β-oxidación de los ácidos grasos, de aminoácidos y de la colina. Defectos en el funcionamiento del complejo resultan en una deficiencia multiple de acil-CoA deshidrogenasas (MADD; aciduria glutárica tipo II; OMIM 231680) que representa un grupo muy heterogéneo de enfermedades metabólicas tanto desde el punto de vista clínico como molecular. Pueden tener como causa mutaciones en los genes que codifican para las subunidades del complejo (ETFA, ETFB y ETFDH), genes que codifican los transportadores de riboflavina, del transporte ó de la síntesis del FAD. Bioquímicamente, las MADD se caracterizan por la acumulación de acilcarnitinas de cadena corta, media y larga, siendo su detección la abordaje primaria al diagnóstico, incluso en cribado neonatal. La multiplicidad de defectos genéticos que pueden cursar por una disfunción del complejo ETF/ETF-QO (creyéndose que siguen sin estar identificados todos), el hecho de que no siempre están presentes los marcadores bioquímicos evidentes (acumulación de las acilcarnitinas características) y la grande variabilidad clínica son factores que conducen a una dificultad aumentada en de diagnóstico de este grupo de errores congénitos del metabolismo. En este panorama el conocimiento de la epidemiologia molecular es fundamental. Los autores presentaran las bases moleculares de los trastornos en el funcionamiento del complejo ETF/ETF-QO en Portugal.
- Biochemical data as important clues for diagnosis of SUCLA2 defectsPublication . Nogueira, Célia; Garcia, Paula; Diogo, Luisa; Valongo, Carla; Santorelli, Filippo; Vilarinho, Laura
- Caracterização molecular do gene TPO em crianças Portuguesas com hipotiroidismo congénito causado por disormonogénesePublication . Nogueira, Célia; Vaz Osório, Rui; Santos, Rosário; Jorge, PaulaCongenital hypothyroidism (CH) affects about 1:4000 infants and is considered one of the main causes of preventable mental retardation in children. Universal screening of CH performed through the Portuguese National Neonatal Screening Programme, implemented in Portugal in 1985, has resulted in normal development of attained children. Birth defects of the thyroid can be divided into several groups that represent either changes in the development of the gland or the consequences observed in the deficient synthesis of thyroid hormones. The defects of hormone synthesis caused by dyshor - monogenesis occur in only 10% to 15% of cases of HC. Defects in the thyroid peroxidase (TPO) gene are reported to be one of the most frequent causes of CH due to dyshormonogenesis. The aim is to review the mutational spectrum of the TPO gene in the portuguese population through the molecular investigation of 69 patients with permanent CH due to dys - hormonogenesis. To complement previous results, published in 2005, this work describes the molecular characterization of a further fourteen children with CH and the methodology applied. Extensive in-silico analysis was carried out for the newly identified sequence changes as well as the formerly published putative splicing variant. The sequence variations identified in the TPO gene comprise ten distinct mutations and 29 polymorphisms, enabling the determination of the molecular etiology of CH in fifteen patients. In conclusion, it was possible to obtain a differential diagnosis in twelve fami - lies with CH, using a non-invasive procedure and without interruption of medication. Identification of these and other mutations in the TPO gene can therefore contribute considerably towards diagnosis, a precise genetic counselling, adequate monitoring in future pregnancies as well as putative personalized therapies.
- Causas metabólicas de rabdomiólise associadas a mutações no gene LPIN1Publication . Nogueira, Célia; Nunes, Diana; Lopes, Altina; Vilarinho, LauraA rabdomiólise resulta da lise do músculo-esquelético, devido à lesão no tecido muscular com consequente libertação de componentes intracelulares do músculo para a corrente sanguínea, originando mioglobinúria e, nos casos mais graves, falência renal aguda. As causas mais frequentes de rabdomiólise são o consumo de álcool, drogas, exercício físico intenso, compressão muscular traumática e infeções. As miopatias metabólicas são causas de rabdomiólise e decorrem da incapacidade em produzir a quantidade de ATP adequada às necessidades das células musculares, por deficiência de enzimas do metabolismo dos glícidos, lípidos ou nucleósidos. Normalmente surgem na infância, sob a forma de fraqueza muscular e mioglobinúria recorrentes após exposição a estímulos que em condições normais não causam necrose muscular, como é o caso do exercício físico ligeiro, infeções virais ou jejum prolongado. Estas doenças são normalmente causadas por defeitos na -oxidação mitocondrial dos ácidos gordos, no entanto alterações no metabolismo da Lipina constituem a segunda causa mais comum de rabdomiólise com início precoce. Esta deficiência é autossómica recessiva e está associada a mutações no gene LPIN1. Neste sentido foi implementado este estudo genético na nossa Unidade, o que permitiu a identificação do primeiro doente português com uma nova mutação no gene LPIN1. Este estudo contribuiu para esclarecer a causa da doença nesta família, expandir o espectro mutacional deste gene, assim como oferecer um aconselhamento genético e diagnóstico pré-natal às famílias afetadas. Os nossos dados corroboram assim a importância do estudo molecular do gene LPIN1 para confirmar doentes (crianças e adultos) com rabdomiólise recorrente. A caraterização molecular destes doentes é importante uma vez que existe a possibilidade de um tratamento adequado.
- Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disordersPublication . Cruz, Simão; Taipa, Ricardo; Nogueira, Célia; Pereira, Cristina; Almeida, Lígia S.; Neiva, Raquel; Geraldes, Tiago; Guimarães, António; Pires, Manuel Melo; Vilarinho, LauraIntroduction: Mitochondrial disorders display remarkable genetic and phenotypic heterogeneity. Methods: We performed a retrospective analysis of the clinical, histological, biochemical, and genetic features of 65 patients with molecular diagnoses of mitochondrial disorders. Results: The most common genetic diagnosis was a single large-scale mitochondrial DNA (mtDNA) deletion (41.5%), and the most frequent clinical phenotype was chronic progressive external ophthalmoplegia (CPEO). It occurred in 41.5% of all patients, primarily in those with mtDNA deletions. Histological signs of mitochondrial dysfunction were found in 73.8% of patients, and respiratory chain enzyme assay (RCEA) abnormalities were detected in 51.9%. Conclusions: This study confirms the high relative frequency of single large-scale deletions among mitochondrial disorders as well as its particular association with CPEO. Muscle histology seems to be particularly useful in older patients and those with mtDNA deletions, whereas RCEA might be more helpful in young children or individuals with mtDNA depletion.
- Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders: authors’ reply to the Drs. Finsterer and Zarrouk-Mahjoub commentsPublication . Cruz, Simão; Taipa, Ricardo; Nogueira, Célia; Melo-Pires, Manuel; Vilarinho, LauraAuthors’ reply to the Drs. Finsterer and Zarrouk-Mahjoub comments for the study “Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders” This study confirms the high relative frequency of single large-scale deletions among mitochondrial disorders as well as its particular association with CPEO. Muscle histology seems to be particularly useful in older patients and those with mtDNA deletions, whereas RCEA might be more helpful in young children or individuals with mtDNA depletion. (Full article reference: Cruz S, Taipa R, Nogueira C, Pereira C, Almeida LS, Neiva R, Geraldes T, Guimarães A, Melo-Pires M, Vilarinho L. Clinical, biochemical, molecular and histological features of 65 Portuguese patients with mitochondrial disorders. Muscle Nerve. 2017 Nov;56(5):868-872. doi: 10.1002/mus.25593. Epub 2017 Apr 4).
- Complex III deficiency in a Portuguese family: expanding the clinical phenotypePublication . Nogueira, Célia; Nesti, Claudia; Meschini, M. Clara; Carrozzo, Rosalba; Barros, José; Sá, Maria José; Azevedo, Luisa; Santorelli, Filippo; Vilarinho, Laura