Browsing by Author "Quelhas, D."
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- Avaliação dos níveis de ácidos gordos essenciais (DHA, AA e EPA) em doentes submetidos a dietas restritivas em proteínasPublication . Pacheco, S.; Ferreira, R.; Quelhas, D.; Martins, E.; Lacerda, L.
- Cistinúria – Revisão da literatura e investigação das suas bases genéticas em 4 doentesPublication . Lopes, A.; Barbosa, M.; Mota, C.; Alves, S.; Martins, E.; Mota, M.C.; Quelhas, D.; Lacerda, L.; Cardoso, M.L.Introdução: Classicamente, e com base na apresentação fenotípica, os doentes com cistinúria classificavam-se em tipo I e tipo não I. Mais recentemente e com base nos aspectos genéticos da doença podemos identificar: o tipo A, causada por mutações no gene SLC3A1, o tipo B, causada por mutações no gene SLC7A9 Objectivos e metodologia: O objectivo deste trabalho foi rever o estado actual do conhecimento no que se refere ao diagnóstico, incidência/prevalência, classificação bioquímica, aspectos genéticos e tratamento desta patologia e caracterizar a nível molecular quatro casos com diagnóstico clínico e/ou bioquímico de cistinúria através da sequenciação dos genes SLC3A1 e SLC7A9. Resultados: No gene SLC3A1 foram detectadas cinco mutações, duas das quais são novas (c.1597T>A e c.611-2A>C) e três previamente descritas na literatura (c.647C>T; c.1190A>G e c.2019C>G). A sequenciação do gene SLC7A9 revelou a presença de uma mutação previamente descrita (c.614_615insA). Foi possível classificar três doentes tipo A (um homozigoto e dois heterozigotos compostos) e um doente como heterozigoto tipo B, o que está de acordo com a excreção urinária de cistina observada. Conclusões: A caracterização genotípica dos doentes cistinúricos contribui para o esclarecimento da patofisiologia da doença, permite efectuar a confirmação do diagnóstico clínico e bioquímicoe oferecer o aconselhamento genético aos familiares em risco. Os autores salientam a importância de uma abordagem multidisciplinar na estratégia de seguimento destes doentes. ABSTRACT Introduction: Classically, based on the phenotype, two types of cystinuria were identifi ed and classifi ed as type I and non-type I. More recently a new classification was proposed based on molecular genetics: cystinuria type A (caused by mutations on SLC3A1 gene), type B (involving mutations on SLC7A9 gene) and type AB if there is a digenic inheritance (SLC3A1 and SLC7A9). Objective and methodology: We reviewed the state of the art on the diagnosis, incidence/prevalence, biochemical classification, genetic data and treatment of cystinuria. Furthermore we characterized four patients with cystinuria at molecular level by sequencing SLC3A1 and SLC7A9 genes. Results: On SLC3A1 we detect five mutations, two of them (c.1597T>A and c.611-2A>C) are novel and three (c.647C>T; c.1190A>G and c.2019C>G) were been previously reported in literature. Sequencing of SLC7A9 gene showed one (c.614_615insA) previously published mutation. It was possible to classify three type A patients (one homozygote and two compound heterozygotes) and one patient as heterozygous type B, which is consistent with the observed urinary excretion of cystine. Conclusions: Genotypic characterization of patients with cystinuria contributes to the understanding of the pathophysiology, confirms the clinical and biochemical diagnosis and provides genetic counseling to relatives at risk. The authors underline the need of a multidisciplinary team approach in the follow-up of these patients.
- Dietary treatment in Phenylketonuria does not lead to increased risk of obesity or metabolic syndromePublication . Rocha, J.C.; van Spronsen, F.; Almeida, M.F.; Soares, G.; Quelhas, D.; Ramos, E.; Guimarães, J.T.; Borges, N.
- Doenças hereditárias do metabolismo estudadas na Unidade de Bioquímica GenéticaPublication . Caseiro, C.; Ribeiro, H.; Silva, E.; Ferreira, C.; Pinto, E.; Ribeiro, I.; Rocha, S.; Laranjeira, F.; Sousa, D.; Pacheco, S.; Pinto, F.; Quelhas, D.; Lacerda, L.
- Doenças lisossomais na etiologia da hidropsia fetal não imunePublication . Ribeiro, H.; Caseiro, C.; Sousa, D.; Pinto, E.; Ribeiro, I.; Laranjeira, F.; Silva, E.; Ferreira, C.; Rocha, S.; Quelhas, D.; Lacerda, L.
- Galactose Epimerase Deficiency: Expanding the PhenotypePublication . Dias Costa, F.; Ferdinandusse, S.; Pinto, C.; Dias, A.; Keldermans, L.; Quelhas, D.; Matthijs, G.; Mooijer, P.; Diogo, L.; Jaeken, J.; Garcia, P.Galactose epimerase deficiency is an inborn error of metabolism due to uridine diphosphate-galactose-4'-epimerase (GALE) deficiency. We report the clinical presentation, genetic and biochemical studies in two siblings with generalized GALE deficiency.Patient 1: The first child was born with a dysmorphic syndrome. Failure to thrive was noticed during the first year. Episodes of heart failure due to dilated cardiomyopathy, followed by liver failure, occurred between 12 and 42 months. The finding of a serum transferrin isoelectrofocusing (IEF) type 1 pattern led to the suspicion of a congenital disorder of glycosylation (CDG). Follow-up disclosed psychomotor disability, deafness, and nuclear cataracts.Patient 2: The sibling of patient 1 was born with short limbs and hip dysplasia. She is deceased in the neonatal period due to intraventricular hemorrhage in the context of liver failure. Investigation disclosed galactosuria and normal transferrin glycosylation.Next-generation sequence panel analysis for CDG syndrome revealed the previously reported c.280G>A (p.[V94M]) homozygous mutation in the GALE gene. Enzymatic studies in erythrocytes (patient 1) and fibroblasts (patients 1 and 2) revealed markedly reduced GALE activity confirming generalized GALE deficiency. This report describes the fourth family with generalized GALE deficiency, expanding the clinical spectrum of this disorder, since major cardiac involvement has not been reported before.
- Genes, crianças e pediatras: defeito congénito da glicosilaçãoPublication . Bandeira, A.; Mota, C.; Quelhas, D.; Loureiro, M.; Martins, E.A 14 month-old boy presented with failure to thrive and severe mental and motor development delay. On physical examination he presented with severe axial hypotonia and dysmorphic syndrome: peculiar facies with small eyes, micrognathia, raised intermamilar distance. He also had multissistemic involvement with nephritic proteinuria, hypertrophy cardiomiopathy with pericardial effusion, raised transaminases, functional deficit of coagulation proteins and unspecific changes of retinal pigmentation. This case illustrates the typical presentation of congenital disorder of glycosilation (CDG) type Ia.
- Genotype-phenotype correlations and BH4 estimated responsiveness in patients with phenylketonuria from Rio de Janeiro, Southeast BrazilPublication . Vieira Neto, Eduardo; Laranjeira, F.; Quelhas, D.; Ribeiro, I.; Seabra, A.; Mineiro, N.; Carvalho, L.; Lacerda, L.; Ribeiro, M.Background: Genetic heterogeneity and compound heterozygosis give rise to a continuous spectrum of phenylalanine hydroxylase deficiency and metabolic phenotypes in phenylketonuria (PKU). The most used parameters for evaluating phenotype in PKU are pretreatment phenylalanine (Phe) levels, tolerance for dietary Phe, and Phe overloading test. Phenotype can vary from a "classic" (severe) form to mild hyperphenylalaninemia, which does not require dietary treatment. A subset of patients is responsive to treatment by the cofactor tetrahydrobiopterin (BH4 ). Genotypes of PKU patients from Rio de Janeiro, Brazil, were compared to predicted and observed phenotypes. Genotype-based estimations of responsiveness to BH4 were also conducted. Methods: Phenotype was defined by pretreatment Phe levels. A standard prediction system based on arbitrary assigned values was employed to measure genotype-phenotype concordance. Patients were also estimated as BH4 -responders according to the responsiveness previously reported for their mutations and genotypes. Results: A 48.3% concordance rate between genotype-predicted and observed phenotypes was found. When the predicted phenotypes included those reported at the BIOPKU database, the concordance rate reached 77%. A total of 18 genotypes from 30 patients (29.4%) were estimated as of potential or probable BH4 responsiveness. Inconsistencies were observed in genotypic combinations including the common "moderate" mutations p.R261Q, p.V388M, and p.I65T and the mild mutations p.L48S, p.R68S, and p.L249F. Conclusion: The high discordance rate between genotype-predicted and observed metabolic phenotypes in this study seems to be due partially to the high frequency of the so-called "moderate" common mutations, p.R261Q, p.V388M, and p.I65T, which are reported to be associated to erratic or more severe than expected metabolic phenotypes. Although our results of BH4 estimated responsiveness must be regarded as tentative, it should be emphasized that genotyping and genotype-phenotype association studies are important in selecting patients to be offered a BH4 overload test, especially in low-resource settings like Brazil.
- Investigação Bioquímica e Molecular na Morte Súbita do Lactente (SIDS)Publication . Cardoso, M.; Pinheiro, J.; Pereira, C.; Sousa, C.; Nogueira, C.; Tesa, A.; Ramos, A.; Balreira, A.; Lima, C.; Valongo, C.; Couto, D.; Quelhas, D.; Fonseca, H.; Rocha, H.; Almeida, L.; Rodrigues, R.; Santos, R.; Santorelli, F.; Vilarinho, L.RESUMO SIDS (Sudden Infant Death Syndrome) é a designação utilizada para definir a morte súbita do lactente, que permanece inexplicada após uma cuidadosa investigação do caso, a qual incluí a realização de autópsia, o exame do local da morte e a análise da história clínica. Devido à rápida deterioração que provocam, as doenças metabólicas constituem potenciais causas de morte súbita, quer pelas crises que ocasionam com intoxicação e comprometimento da sobrevivência do indivíduo, quer por provocarem alterações que aumentam o risco de falência de determinados orgãos. Objectivos: Com este trabalho pretendemos avaliar o contributo relativo das doenças metabólicas e dos défices energéticos nas situações de morte súbita e inexplicada do lactente, na população portuguesa. Pacientes e Métodos: Foram disponibilizadas para investigação amostras biológicas congeladas de 51 lactentes cuja causa de morte era desconhecida. Os produtos foram colhidos durante a autópsia e incluíram: soro, urina, humor vítreo, músculo e fígado. Nos fluídos biológicos fez-se o estudo dos aminoácidos e dos ácidos orgânicos e nos tecidos sólidos o doseamento da actividade dos vários complexos da cadeia respiratória mitocondrial e do teor em glicogénio. Foi ainda efectuada a extracção de DNA total a partir dos tecidos sólidos acima referidos o qual foi utilizado para estudos moleculares. Resultados: Foi possível identificar através dos estudos moleculares um caso de intolerância hereditária à frutose - HFI (homozigotia para a mutação A149P no gene ALDOB). Nos estudos bioquímicos foi encontrado um caso positivo de very long-chain acyl-CoA dehydrogenase - VLCAD e na maioria das determinações efectuadas, desvios em relação aos controlos normais inerentes ao catabolismo e aos processos de cadaverização, sendo de salientar: valores muito elevados dos aminoácidos séricos e a presença sistemática de grande quantidade de ácido láctico na urina. Conclusões: Nas doenças metabólicas o risco de recorrência existe e a identificação de um caso classificado como SIDS, como sendo na realidade um erro inato do metabolismo, é importante para a família, quer em termos de instituição de tratamento adequado e adopção de medidas preventivas, quer em termos de aconselhamento genético. ABSTRACT SIDS (Sudden Infant Death Syndrome) is the sudden and unexpected death including performance of a complete autopsy, examination of death scene, and review of clinical history. Metabolic disorders can lead to sudden dead because they cause crises of intoxication and life threatening, with dysfunction of several organs, that raise the risk of general failure. Objectives: Our main objective with this study, was to evaluate the significance of metabolic disorders and energy deficiencies in sudden infant death syndrome, in Portuguese population. Patients and Methods: We got biological frozen samples from 51 children whose cause of dead was unknown. The products were collected during autopsy and included: serum, urine, humour vitreous, muscle and liver. In the biological fluids samples we analysed amino acids as well as organic acids, and in referred tissues we determinate the activity of the respiratory chain complexes and the amount of glycogen. It was also possible to get total DNA from solid tissues which was used for molecular studies. Results: Based on molecular findings, it was possible to identify one case of fructose intolerance - HFI (patient homozygous for A149P in ALDOB gene). Biochemical studies revealed one case of very long-chain acyl-CoA dehydrogenase - VLCAD deficiency. However, in the majority of the assays performed deviations from normal controls were found, due to catabolism post-morten (plasmatic increase of amino acids and high excretion of lactic acid in urine). Conclusions: In metabolic disorders the risk of recurrence exists. The misdiagnosed inherited errors of metabolism as SIDS, it is important for the family, in terms of treatment, prevention attitude and genetic counselling. of an infant which remains unexplained
- MAN1B1 Deficiency: An Unexpected CDG-IIPublication . Rymen, D.; Peanne, R.; Millón, M.; Race, V.; Sturiale, L.; Garozzo, D.; Mills, P.; Clayton, P.; Asteggiano, C.; Quelhas, D.; Cansu, A.; Martins, E.; Nassogne, M.; Gonc¸alves-Rocha, M.; Topaloglu, H.; Jaeken, J.; Foulquier, F.; Matthijs, G.Congenital disorders of glycosylation (CDG) are a group of rare metabolic diseases, due to impaired protein and lipid glycosylation. In the present study, exome sequencing was used to identify MAN1B1 as the culprit gene in an unsolved CDG-II patient. Subsequently, 6 additional cases with MAN1B1-CDG were found. All individuals presented slight facial dysmorphism, psychomotor retardation and truncal obesity. Generally, MAN1B1 is believed to be an ER resident alpha-1,2-mannosidase acting as a key factor in glycoprotein quality control by targeting misfolded proteins for ER-associated degradation (ERAD). However, recent studies indicated a Golgi localization of the endogenous MAN1B1, suggesting a more complex role for MAN1B1 in quality control. We were able to confirm that MAN1B1 is indeed localized to the Golgi complex instead of the ER. Furthermore, we observed an altered Golgi morphology in all patients' cells, with marked dilatation and fragmentation. We hypothesize that part of the phenotype is associated to this Golgi disruption. In conclusion, we linked mutations in MAN1B1 to a Golgi glycosylation disorder. Additionally, our results support the recent findings on MAN1B1 localization. However, more work is needed to pinpoint the exact function of MAN1B1 in glycoprotein quality control, and to understand the pathophysiology of its deficiency.