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Free PMC article: https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/31497476/ In the era of genomics, the number of genes linked to mitochondrial disease has been quickly growing, producing massive knowledge on mitochondrial biochemistry. LYRM4 gene codifies for ISD11, a small protein (11 kDa) acting as an iron-sulfur cluster, that has been recently confirmed as a disease-causing gene for mitochondrial disorders. We present a 4-year-old girl patient, born from non-consanguineous healthy parents, with two episodes of cardiorespiratory arrest after respiratory viral illness with progressive decreased activity and lethargy, at the age of 2 and 3 years. She was asymptomatic between crisis with regular growth and normal development. During acute events of illness, she had hyperlactacidemia (maximum lactate 5.2 mmol/L) and urinary excretion of ketone bodies and 3-methylglutaconic acid, which are normalized after recovery. A Next Generation Sequence approach with a broad gene panel designed for mitochondrial disorders revealed a novel probably pathogenic variant in homozygosity in the LYRM4 gene [p.Tyr31Cys (c.92A>G)] with Mendelian segregation. Functional studies in the skeletal muscle confirmed a combined deficiency of the mitochondrial respiratory chain (I, II, and IV complexes). To our knowledge, this is the third case of LYRM4 deficiency worldwide and the first with 3-methylglutaconic aciduria, not reported in any Fe-S cluster deficiency. Remarkably, it appears to be no neurological involvement so far, only with life-threating acute crisis triggered by expectably benign autolimited illnesses. Respiratory chain cofactors and chaperones are a new field of knowledge and can play a remarkable effect in system homeostasis. Fundação para a Ciência e a Tecnologia, Grant/Award Number: PTDC/DTP‐PIC/2220/2014; NORTE2020, Grant/Award Number: NORTE‐01‐0246‐FEDER‐000014 info:eu-repo/semantics/publishedVersion

Technological development is key for national strategies to cope with the Paris Agreement's goals. Technology Needs Assessments (TNAs) aim to identify, prioritize, and diffuse climate change mitigation and/or adaptation technologies in developing countries. Their methodology includes a multi-criteria decision analysis (MCDA) framework but, although many countries already conducted a TNA, literature lacks discussions on country-specific processes for a TNA, as it usually follows a one-size-fits-all approach. This paper provides empirical evidence on the importance of country-driven processes that help shaping international programmes into country-specific needs and capabilities. It presents lessons learned from a tailored process for identification, prioritization, and selection of mitigation technologies in the scope of a TNA project for Brazil, an exceptional case of a developing country with strong capacity in integrated assessment modelling (IAM) scenarios for guiding its climate strategies. A previous IAM scenario result allowed pre-selecting technologies in six key economic sectors, while other TNAs prioritized no more than three. This allowed the elaboration of an overall ranking from the MCDA, in contrast to sectoral rankings that are mostly employed in other countries' TNAs. The overall ranking serves not only as a basis for the selection of priority technologies but also provides information on the integrated innovations framework for climate technologies in the country. Further specific findings of the tailored Brazilian TNA approach are discussed in the paper in order to call for the importance that a technology transfer project should not only be country-driven but also conducted through a country-specific process.The online version contains supplementary material available at 10.1007/s11027-022-10025-6.

Increased sugar intake is implicated in Type-2 diabetes and fatty liver disease; however, the mechanisms through which glucose and fructose promote these conditions are unclear. We hypothesize that alterations in intestinal metabolite and microbiota profiles specific to each monosaccharide are involved. Two groups of six adult C57BL/6 mice were fed for 10-weeks with diets with glucose (G) or fructose (F) as sole carbohydrates, and a third group was fed with a normal chow carbohydrate mixture (N). Fecal metabolites were profiled by nuclear magnetic resonance (NMR) and microbial composition by real-time polymerase chain reaction (qPCR). Although N, G and F mice exhibited similar weight gains (with slight slower gains for F) and glucose tolerance, multivariate analysis of NMR data indicated that F mice were separated from N and G, with decreased butyrate and glutamate and increased fructose, succinate, taurine, tyrosine, and xylose. The different sugar diets also resulted in distinct intestinal microbiota profiles. That associated with fructose seemed to hold more potential to induce host metabolic disturbances compared to glucose, mainly by promoting bile acid deconjugation and taurine release and compromising intestinal barrier integrity. This may reflect the noted nonquantitative intestinal fructose absorption hence increasing its availability for microbial metabolism, a subject for further investigation.

To assess longitudinal peri-implant tissue evaluation in a plaque compromised ligature free dog model, clinically, radiographically, microbiologically and histologically. Six beagle mandibular premolars and first molars were extracted. Plaque accumulated for 16 weeks. Two implants were placed per hemi-mandible. For 17 weeks, control implants (CI) in one hemi-mandible were brushed daily; test implants (TI) in the other were not. These parameters were then assessed: clinically, probing depth (PD), bleeding-on-probing (BOP), presence of plaque (PP) and clinical attachment level (CAL); radiographically, marginal bone level; microbiologically, counts for Streptococcus spp., Fusobacterium spp., Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and total bacterial load. At week 17, histomorphometric analysis was performed (MM-ISH (mucosal margin–implant shoulder); ISH-fBIC (implant shoulder–first bone-to-implant contact); MM-aJE (mucosal margin–apical area junctional epithelium); MM-aINF (mucosal margin–apical limit of the inflammatory infiltrate); %INF (percentage of inflammatory infiltrate)). At week 17, TI had significant increased PD, BOP, PP and CAL versus baseline. All clinical variables presented intergroup differences. There was no intergroup difference for radiographic bone loss (p > 0.05). Total bacteria, Fusobacterium spp., A. actinomycetemcomitans and P. gingivalis had intergroup differences. There was no statistically significant intergroup difference for ISH-fBIC. Longitudinal microbiology evaluation detected a shift period. Final intergroup microbiological differences were the basis of W17 clinical intergroup differences, with higher values in TI. Microbiological and clinical changes detected in peri-implant tissues were compatible with onset of peri-implant disease. Despite histological inflammatory intergroup difference, no histological or radiographic intergroup bone loss was detected. This study set-up describes a valuable method for generating “true” early peri-implant defects without mechanical trauma.

Mitochondrial diseases (MD) are a group of rare inherited disorders, characterized by phenotypic heterogeneity, with hitherto no effective therapeutic options. The aim of this study was to develop a next generation sequencing (NGS) strategy, by using a custom gene panel and whole mitochondrial genome, to identify the disease causing pathogenic variants in 146 patients suspicious of MD. The molecular analysis of this cohort revealed six novel and 15 described pathogenic variants, as well as 26 variants of unknown significance. Our findings are expanding the mutational landscape of these disorders and support the use of a NGS strategy for a higher diagnostic yield. This work was supported by FCT (PTDC/DTP-PIC/2220/2014) and NORTE2020 (NORTE-01-0246-FEDER-000014). Silvia Vilarinho is supported by the National Institute Of Diabetes And Digestive And Kidney Diseases of the National Institutes of Health under Award Number K08DK113109. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. info:eu-repo/semantics/publishedVersion

Background: Multiple Acyl-CoA Dehydrogenase Deficiency (MADD) is a congenital rare metabolic disease with broad clinical phenotypes and variable evolution. This inborn error of metabolism is caused by mutations in the ETFA, ETFB or ETFDH genes, which encode for the mitochondrial ETF and ETF:QO proteins. A considerable group of patients has been described to respond positively to riboflavin oral supplementation, which constitutes the prototypic treatment for the pathology. Objectives: To report mutations in ETFA, ETFB and ETFDH genes identified in Portuguese patients, correlating, whenever possible, biochemical and clinical outcomes with the effects of mutations on the structure and stability of the affected proteins, to better understand MADD pathogenesis at the molecular level. Methods: MADD patients were identified based on the characteristic urinary profile of organic acids and/or acylcarnitine profiles in blood spots during newborn screening. Genotypic, clinical and biochemical data were collected for all patients. In silico structural analysis was employed using bioinformatic tools carried out in an ETF:QO molecular model for the identified missense mutations. Results: A survey describing clinical and biochemical features of eight Portuguese MADD patients was made. Genotype analysis identified five ETFDH mutations, including one extension (p.X618QextX*14), two splice mutations (c.34+5G>C and c.405+3A>T) and two missense mutations (ETF:QO-p.Arg155Gly and ETF:QO-p.Pro534Leu), and one ETFB mutation (ETFβ- p.Arg191Cys). Homozygous patients containing the ETFDH mutations p.X618QextX*14, c.34+5G>C and ETF:QO-p.Arg155Gly, all presented severe (lethal) MADD phenotypes. However, when any of these mutations are in heterozygosity with the known ETF:QO-p.Pro534Leu mild variant, the severe clinical effects are partly and temporarily attenuated. Indeed, the latter destabilizes an ETF-interacting loop, with no major functional consequences. However, the position 155 in ETF:QO is localized at the ubiquinone binding and membrane interacting domain, and is thus expected to perturb protein structure and membrane insertion, with severe functional effects. Structural analysis of molecular models is therefore demonstrated to be a valuable tool to rationalize the effects of mutations in the context of the clinical phenotype severity. Conclusion: Advanced molecular diagnosis, structural analysis and clinical correlations reveal that MADD patients harboring a severe prognosis mutation in one allele can actually revert to a milder phenotype by complementation with a milder mutation in the other allele. However, such patients are nevertheless in a precarious metabolic balance which can revert to severe fatal outcomes during catabolic stress or secondary pathology, thus requiring strict clinical follow-up. This work was supported by the Fundação para a Ciência e Tecnologia (FCT/MCTES, Portugal) through fellowships to B.J.H. (SFRH/BPD/74475/2010) and T.G.L. (SFRH/BD/89690/2012) and a grant PTDC/ BBB-BQB/5366/2014 (to B.J.H.) and PTDC/NEUNMC/2138/2014 (to C.M.G.). The Gomes laboratory is partly supported by grant UID/MULTI/04046/2013 from FCT/MCTES/PIDDAC (to BioISI). info:eu-repo/semantics/publishedVersion

Leigh syndrome is a devastating neurodegenerative disease, typically manifesting in infancy or early childhood. Hallmarks of the disease are symmetrical lesions in the basal ganglia or brain stem on MRI, and a clinical course with rapid deterioration of cognitive and motor functions. It is genetically heterogeneous, causative mutations have been disclosed in mitochondrial DNA and nuclear genes involved in the process of energy production in the mitochondria .We investigated the whole mitochondrial DNA in three Brazilian patients with LS, based on their clinical and biochemical data, with the aim to identify the disease-causing mutations. In two of the patients, with complex I deficiency, a novel heteroplasmic variant m.4142G>T (p.R279L) in MT-ND1 and a recurrent homoplasmic mutation m.10197G>A (p.A47T) in MT-ND3 were identified. In the remaining patient, with complex IV deficiency, a de novo heteroplasmic variant in MT-CO1 m.6547T>C (p.L215P) was found. The molecular investigation in mitochondrial diseases have shifted their focus from mitochondrial DNA to nuclear DNA, however, mtDNA protein-coding genes are one of the important genetic causes of mitochondrial disorders for Leigh syndrome. This study expands the molecular and clinical spectrum associated with this disease.

Este artigo objetivou analisar as contribuições das ações do Programa Nacional de Assistência Estudantil, na percepção de estudantes de baixa condição socioeconômica, a partir do 4º período do curso de graduação de uma universidade pública federal localizada em Belo Horizonte, entre 2011 e 2014. Foi realizado um estudo de caso, descritivo e qualitativo. Para a coleta de dados foram aplicados questionários totalizando o número de alunos bolsistas do referido Programa, de acordo com o período estabelecido, obtendo-se o retorno de 124 questionários. As entrevistas foram efetuadas por meio de roteiro semiestruturado, tendo sido escolhidos 20 estudantes por acessibilidade e o critério que determinou este número foi o de saturação de dados. Os resultados apontam que o referido Programa, na ótica dos pesquisados, contribui para a permanência, a formação acadêmica e a inclusão social.

O recente desenvolvimento da tecnologia de sequenciação de nova geração (NGS) revolucionou o diagnóstico molecular das doenças genéticas raras, de difícil diagnóstico, tais como as doenças mitocondriais. O estudo destas patologias foi implementado em 1993 pelo nosso grupo e até à data foram investigados mais de 2500 doentes portugueses. Muitos destes doentes ainda não dispõem de diagnóstico molecular, pelo que foi desenvolvida uma estratégia de NGS para a identificação da mutação causal. A sequenciação de um painel de 209 genes nucleares associados a doenças mitocondriais e do DNA mitocondrial completo por NGS, foi realizada num sequenciador MiSeq (Illumina). O estudo de 145 doentes permitiu identificar 41 mutações causais e caraterizar 35 doentes. Esta investigação contribuiu para esclarecer a etiologia molecular destes doentes (35/145; 24%), ii) alargar o espetro mutacional destas patologias e, iii) oferecer um aconselhamento genético e um eventual diagnóstico pré-natal aos casais em risco. O desenvolvimento de um painel, específico para estas patologias, tem um caráter inovador e reforça o nosso Centro como laboratório nacional para o estudo e investigação de doenças mitocondriais. Recent development of high throughput, next-generation sequencing (NGS) technology has revolutionized the research and molecular diagnosis of hardto- diagnose genetic disorders such as mitochondrial disorders. The study of these diseases was implemented in 1993 by our group and to date more than 2,500 Portuguese patients have been investigated. As many of these patients do not yet have molecular diagnosis, an NGS strategy was developed to identify the causal mutation. NGS was performed in a MiSeq Illumina instrument using a custom mitochondrial gene panel with around 209 genes involved in mitochondria metabolism and the entire human mitochondrial genome. The study of 145 patients allowed the identification of 41 causal mutations and the molecular characterization of 35 patients. This investigation contributed to i) identify the pathogenic mutations in the studied patients (35/145; 24%), ii) expand the mutational spectrum in the etiology of these disorders, and iii) propose an accurate genetic counseling. Custom design panels have been widely used for molecular heterogeneous disorders however, the development of this panel will be innovative in our country strengthening our Center as a national reference for the study and research of mitochondrial disorders. Estudo financiado por: Fundação da Ciência e Tecnologia (PTDC/DTP-PIC/2220/2014, Genetic Defects of Mitochondrial Diseases: a Next Generation Sequencing Approach) - implementação da tecnologia de NGS e o desenho de um painel de genes nucleares aplicado ao diagnóstico das doenças mitocondriais; Programa NORTE 2020 (NORTE-01-0246-FEDER-000014, DESVENDAR “DEScobrir, VENcer as Doenças rARas”) - aquisição de equipamentos para a realização da sequenciação de nova geração. info:eu-repo/semantics/publishedVersion

Increased sugar intake is implicated in Type-2 diabetes and fatty liver disease. Mechanisms by which glucose and fructose components promote these conditions are unclear. We hypothesize that alterations in intestinal metabolite and microbiota profiles specific to each monosaccharide are involved. Two groups of six adult C57BL/6 mice were fed for 10-weeks with a diet where either glucose or fructose was the sole carbohydrate component (G and F, respectively). A third group was fed with normal chow (N). Fecal metabolites were profiled every 2-weeks by 1H NMR and microbial composition was analysed by real-time PCR (qPCR). Glucose tolerance was also periodically assessed. N, G and F mice had similar weight gains and glucose tolerance. Multivariate analysis of NMR profiles indicated that F mice were separated from both N and G, with decreased butyrate and glutamate and increased fructose, succinate, taurine, tyrosine and xylose. Compared to N and G, F mice showed a shift in microbe populations from gram-positive Lactobacillus spp. to gram-negative Enterobacteria species. Substitution of normal chow carbohydrate mixture by either pure glucose or fructose for 10 weeks did not alter adiposity or glucose tolerance. However, F G and N mice generated distinctive fecal metabolite signatures with incomplete fructose absorption as a dominant feature of F mice.

Cystathionine-β-synthase (CBS) deficiency is the main cause of homocystinuria. Homocysteine (Hcy), methionine, and other metabolites of Hcy accumulate in the body of affected patients. Despite the fact that thromboembolism represents the major cause of morbidity in CBS-deficient patients, the mechanisms of cardiovascular alterations found in homocystinuria remain unclear. In this work, we evaluated the lipid and inflammatory profile, oxidative protein damage, and the activities of the enzymes paraoxonase (PON1) and butyrylcholinesterase (BuChE) in plasma of CBS-deficient patients at diagnosis and during the treatment (protein-restricted diet supplemented with pyridoxine, folic acid, betaine, and vitamin B12). We also investigated the effect of folic acid and vitamin B12 on these parameters. We found a significant decrease in HDL cholesterol and apolipoprotein A1 (ApoA-1) levels, as well as in PON1 activity in both untreated and treated CBS-deficient patients when compared to controls. BuChE activity and IL-6 levels were significantly increased in not treated patients. Furthermore, significant positive correlations between PON1 activity and sulphydryl groups and between IL-6 levels and carbonyl content were verified. Moreover, vitamin B12 was positively correlated with PON1 and ApoA-1 levels, while folic acid was inversely correlated with total Hcy concentration, demonstrating the importance of this treatment. Our results also demonstrated that CBS-deficient patients presented important alterations in biochemical parameters, possibly caused by the metabolites of Hcy, as well as by oxidative stress, and that the adequate adherence to the treatment is essential to revert or prevent these alterations. This work was supported in part by grants from CAPES, CNPq, and FIPE/HCPA-Brazil.

Inborn errors of metabolism (IEMs) are individually rare but collectively common. As more and more genes are cloned and specific disease-causing mutations are identified, the diagnosis of IEMs is becoming increasingly confirmed by mutation analysis. Diagnosis is important not only for treatment and prognosis but also for genetic counselling and prenatal diagnosis in subsequent pregnancies. A wide range of molecular methods is available for the identification of mutations and other DNA variants, most of which are based on the Polymerase Chain Reaction (PCR). In this chapter, we focus on PCR-based methods for the detection of point mutations or small deletions/insertions as these are the most frequent causes of IEMs.

Objective Birth prevalence of Cobalamin (Cbl) C or D defects in Portugal is an estimated 1:85,000, one of the highest worldwide. We compared the genotype/phenotype of patients identified with CblC or CblD before and after the implementation of expanded newborn screening. Methods Twenty-five Portuguese CblC/D patients, 14 symptomatic and 11 identified through screening, were diagnosed using gas chromatography or tandem mass spectrometry. Molecular characterization was performed through the study of MMACHC and MMADHC genes. Results The most common MMACHC mutation, c.271dupA, was present in 100% of MMACHC alleles of all CblC screened patients, in contrast with the 61% identified before expanded newborn screening. All studied cases (except one, who presented a CblD deficiency) presented a CblC defect. More CblC late-onset patients were diagnosed before the introduction of newborn screening than in the post newborn screening era, probably because some early onset patients died without a definitive diagnosis. Conclusion The molecular data found in this cohort contribute to the improvement of screening and diagnosis of Cbl defects and would enable a confirmatory diagnosis of these patients, reducing the need for complex, costly, laborious, and time-consuming biochemical/enzymatic tests.

Inborn errors of metabolism (IEMs) are individually rare but collectively common. As more and more enes are cloned and specific disease-causing mutations are identified, the diagnosis of IEMs is becoming increasingly confirmed by mutation analysis. Diagnosis is important not only for treatment and prognosis but also for genetic counselling and prenatal diagnosis in subsequent pregnancies. A wide range of molecular methods is available for the identification of mutations and other DNA variants, most of which are based on the Polymerase Chain Reaction (PCR). In this chapter, we focus on PCR-based methods for the detection of point mutations or small deletions/insertions as these are the most frequent causes of IEMs. info:eu-repo/semantics/publishedVersion

Parvovirus infection is usually asymptomatic especially in immunocompetent adults. When symptomatic it can range from mild to life threatening depending on the patient’s age and comorbidities. We report a case of a 40-year-old male patient with parvovirus infection who presented a purpuric rash in distal extremities, acute kidney injury, type II mixed cryoglobulinaemia and hypocomplementaemia. His renal biopsy showed a mesangioproliferative glomerulonephritis with positive immunoreactivity to C3, IgM and C1q. Parvovirus B19 was detected in the biopsy tissue by PCR. He was treated with prednisolone with total remission after 1 month. We discuss the diagnosis of kidney lesion due to parvovirus in an immunocompetent person, which is a very rare condition and its association with the cryoglobulinaemia diagnosis.

Adenosine neuromodulation depends on a balanced activation of inhibitory A₁ (A₁R) and facilitatory A(₂A) receptors (A(₂A) R). Both A₁ R and A(₂A) R modulate hippocampal glutamate release and NMDA-dependent long-term potentiation (LTP) but ageing affects the density of both A₁ R and A(₂A) R. We tested the effects of selective A₁ R and A(2A) R antagonists in the modulation of synaptic transmission and plasticity in rat hippocampal slices from three age groups (young adults, 2-3 month; middle-aged adults, 6-8 months; aged, 18-20 months). The selective A(₂A) R antagonist SCH58261 (50 nm) attenuated LTP in all age groups, with a larger effect in aged (-63 ± 7%) than in middle-aged adults (-36 ± 9%) or young adult rats (-36 ± 9%). In contrast, the selective A₁ R antagonist DPCPX (50 nm) increased LTP magnitude in young adult rats (+42 ± 6%), but failed to affect LTP magnitude in the other age groups. Finally, in the continuous presence of DPCPX, SCH58261 caused a significantly larger inhibition of LTP amplitude in aged (-71 ± 45%) than middle-aged (-28 ±9%) or young rats (-11 ± 2%). Accordingly, aged rats displayed an increased expression of A(₂A) R mRNA in the hippocampus and a higher number of glutamatergic nerve terminals equipped with A(2A) R in aged (67 ± 6%) compared with middle-aged (34 ± 7%) and young rats (25 ± 5%). The results show an enhanced A(₂A) R-mediated modulation of LTP in aged rats, in accordance with the age-associated increased expression and density of A(₂A) R in glutamatergic terminals. This age-associated gain of function of A(₂A) R modulating synaptic plasticity may underlie the ability of A(₂A) R antagonists to prevent memory dysfunction in aged animals.

Methylmalonic aciduria (MMA) and homocystinuria, cblC type (MIM 277400) is the most frequent inborn error of vitamin B 12 . The recent identification of the disease gene, MMACHC , has permitted preliminary genotype–phenotype correlations. We studied 24 Italian and 17 Portuguese patients with cblC defect to illustrate the spectrum of mutations in a southern European population and discuss the impact that mutation identification has on routine diagnostic procedures. Since the metabolic defect raises the serum levels of homocysteine, we also tested if variants in MTHFR —playing a key role in homocysteine remethylation pathway—could act as genetic modifier in cblC defect. We found that the c.271dupA (accounting for 55% of the MMACH alleles in our cohort) followed by c.394C>T (16%) and c.331C>T (9%) were the most frequent mutations. In our study we also identified a novel mutation (c.544T>C). On the other hand, the MTHFR genotype did not appear to influence age at onset, the clinical phenotype and outcome of patients with cblC defect. This study shows that mutation screening for the most common MMACH mutations occurring in early-onset forms (c.271dupA and c.331C>T) seems to have a high diagnostic yield in a southern European population with cblC defect. Although the identification of the gene defect per se does not predict completely time and severity of disease appearance, our data corroborate the importance of a molecular testing to offer accurate prenatal diagnosis to couples at high risk of having affected children.

Rhabdomyolysis (RM) is characterized by acute and often severe skeletal muscle damage resulting in myoglobinuria and, in severe cases, acute renal failure [1]. In adults is typically due to trauma, intoxication or infection, whereas in children is frequently associated with inherited muscle disorders [2]. LPIN1 mutations were identified as a cause of severe recurrent RM, which usually begin in childhood, and infections are the most frequent trigger [[3], [4]]. LPIN1 spans 19 exons and encodes lipin-1, an 890 amino acid protein predominantly expressed in skeletal muscle and adipose tissue, which accounts for phosphatidic acid phosphatase activity [[2], [5]]. To date, 36 LPIN1 mutations have been described related with RM (Fig. 1a).

Kawasaki disease (KD) is an acute febrile multisystem vasculitic syndrome of unknown etiology, occurring mostly in infants and children younger than 5 years of age. We present a 13-month-old male with KD from whom was found human bocavirus DNA in nasopharyngeal secretions. Human bocavirus DNA in a patient with KD raised question about the coincidental or possible etiological association.

Introduction: Viral protein R (Vpr) of human immunodeficiency virus type 1 (HIV‐1) has been described as being involved in the progression of AIDS, and specific mutations are associated with long‐term non‐progressor patients. Case presentation: We describe the case of a child with repeated ear infections who was otherwise healthy. The patient, a 5‐year‐old boy, was HIV‐1 positive and the viral load at admission was 1 073 899 RNA copies ml−1 and 0 % CD4+ lymphocytes. A detailed study of the vpr gene sequence of the child revealed mutations leading to amino acid substitutions at positions 3 and 77. Conclusion: The case reported provides clinical support of previous findings that show that the R77Q and Q3R HIV‐1 Vpr variants are associated with patients with delayed disease progression.

Succinyl-coenzyme A synthase is a mitochondrial matrix enzyme that catalyzes the reversible synthesis of succinate and adenosine triphosphate (ATP) from succinyl-coenzyme A and adenosine diphosphate (ADP) in the tricarboxylic acid cycle. This enzyme is made up of α and β subunits encoded by SUCLG1 and SUCLA2, respectively. We present a child with severe muscular hypotonia, dystonia, failure to thrive, sensorineural deafness, and dysmorphism. Metabolic investigations disclosed hyperlactacidemia, moderate urinary excretion of methylmalonic acid, and elevated levels of C4-dicarboxylic carnitine in blood. We identified a novel homozygous p.M329V in SUCLA2. In cultured cells, the p.M329V resulted in a reduced amount of the SUCLA2 protein, impaired production of mitochondrial ATP, and enhanced production of reactive oxygen species, which was partially reduced by using 5-aminoimidazole-4-carboxamide ribonucleotide in the culture medium. Expanding the array of SUCLA2 mutations, we suggested that reactive oxygen species scavengers are likely to impact on disease prognosis. This work was partially supported by the National Institute of Health, INSA, (to LV). CeN’s work was performed as part of her PhD thesis under the rules of the Portuguese Foundation for Science and Technology (SFRH/BD/ 45247/2008). The Transnational Cooperation between FCT/CAPES 2013/2014 partially supported, as well, the work of both researchers (Project 6818).

A homocistinúria devida à deficiência da enzima cistationina -sintetase ou “homocistinúria clássica” é uma doença metabólica rara (1/344 000 RN), de transmissão autossómica recessiva e caracterizada por elevada heterogeneidade clínica, que frequentemente contribui para o diagnóstico tardio. Existe tratamento efetivo, se instituído antes de se instalarem sintomas irreversíveis, pelo que tem sido incluída num número considerável de programas de rastreio neonatal. O rastreio baseia-se na determinação dos níveis plasmáticos de metionina, por espectrometria de massa em tandem (ms/ms), mas conduz à identificação de muitos casos falsos-positivos, portadores de uma condição com significado clínico não completamente esclarecido, a deficiência em metionina adenosiltransferase (MAT I/III). Ambas as condições são rastreadas na Galiza e em Portugal desde 2000 e 2004, respetivamente. Desde então, foram identificados três doentes com homocistinúria clássica e 44 doentes com deficiência em MAT I/III. Uma forma dominante, e aparentemente benigna, desta última condição, associada à mutação p.R264H, parece ser muito frequente na Península Ibérica. A implementação de um teste de segunda linha, consistindo na determinação da homocisteína total, permitiria reduzir consideravelmente o número de RN identificados com deficiência em MAT I/III e melhorar a especificidade e valor positivo preditivo do rastreio da homocistinúria clássica. Homocystinuria due to cystathionine -synthase deficiency or “classical homocystinuria” is a rare autosomal recessive condition characterized by high clinical heterogeneity, which contributes to frequent late clinical diagnosis. Treatment is effective if started before irreversible clinical symptoms, which led to its inclusion in a number of newborn screening programs, based on the analysis of methionine levels by tandem mass spectrometry (ms/ms). Nevertheless, false-positive results can be frequently obtained and lead to the unwanted identification of methionine adenosyl transferase (MAT I/III) deficiency, a condition with clinical significance not completely elucidated. Both these metabolic disorders are screened in Galicia and Portugal since the introduction of the ms/ms technology, in 2000 and 2004, respectively, resulting in the identification of three patients with classical homocystinuria and 44 patients with MAT I/III deficiency. A dominant form of MAT I/III deficiency, associated with mutation p.R264H, seems to be very frequent in the Iberian Peninsula and usually is associated with a clinically benign course. The implementation of a second-tier test for homocysteine determination in dried blood spots would considerably reduce the number of MAT I/III-deficient patients identified and improve the specificity and positive predictive value for classical homocystinuria screening. Parte do trabalho realizado na Galiza foi financiado pelo projeto European network and Registr y for Homocystinurias and Methylation Defects – EHOD (N_2012_12_02).

Deficiency of very-long-chain acyl-CoA dehydrogenase (VLCAD) is an autosomal recessive disease. Most common phenotypes occur in the neonatal period or in childhood with cardiomyopathy, hepatomegaly, and hypoketogenic hypoglycemia. Juvenile/adult-onset is characterized by exercise intolerance and recurrent rhabdomyolysis triggered by prolonged exercise or fasting. This article reports a patient with the homozygous mutation c.1097G>A (p.R366H) in the ACADVL gene. In Portugal, VLCAD deficiency became part of the neonatal screening plan in 2004, and as of 2012, 8 early-onset cases have been diagnosed, giving an incidence rate of 1:97.238 per 737.902 newborns. This patient was diagnosed outside of the neonatal screening plan. Beta-oxidation defects pose a diagnostic challenge because of their transient clinical and laboratorial manifestations and the absence of morphological changes in muscle biopsy further complicate matters, especially in the late-onset forms of the disease. The adult phenotype of VLCAD deficiency is highlighted, emphasizing the need for a high suspicion index and the value of tandem mass spectrometry for the diagnosis.

Letter to the Editor

Letter to the Editor

Complex III of the mitochondrial respiratory chain (CIII) catalyzes transfer of electrons from reduced coenzyme Q to cytochrome c. Low biochemical activity of CIII is not a frequent etiology in disorders of oxidative metabolism and is genetically heterogeneous. Recently, mutations in the human tetratricopeptide 19 gene (TTC19) have been involved in the etiology of CIII deficiency through impaired assembly of the holocomplex. We investigated a consanguineous Portuguese family where four siblings had reduced enzymatic activity of CIII in muscle and harbored a novel homozygous mutation in TTC19. The clinical phenotype in the four sibs was consistent with severe olivo–ponto–cerebellar atrophy, although their age at onset differed slightly. Interestingly, three patients also presented progressive psychosis. The mutation resulted in almost complete absence of TTC19 protein, defective assembly of CIII in muscle, and enhanced production of reactive oxygen species in cultured skin fibroblasts. Our findings add to the array of mutations in TTC19, corroborate the notion of genotype/phenotype variability in mitochondrial encephalomyopathies even within a single family, and indicate that psychiatric manifestations are a further presentation of low CIII.

Adenosine neuromodulation depends on a balanced activation of inhibitory A₁ (A₁R) and facilitatory A(₂A) receptors (A(₂A) R). Both A₁ R and A(₂A) R modulate hippocampal glutamate release and NMDA-dependent long-term potentiation (LTP) but ageing affects the density of both A₁ R and A(₂A) R. We tested the effects of selective A₁ R and A(2A) R antagonists in the modulation of synaptic transmission and plasticity in rat hippocampal slices from three age groups (young adults, 2-3 month; middle-aged adults, 6-8 months; aged, 18-20 months). The selective A(₂A) R antagonist SCH58261 (50 nm) attenuated LTP in all age groups, with a larger effect in aged (-63 ± 7%) than in middle-aged adults (-36 ± 9%) or young adult rats (-36 ± 9%). In contrast, the selective A₁ R antagonist DPCPX (50 nm) increased LTP magnitude in young adult rats (+42 ± 6%), but failed to affect LTP magnitude in the other age groups. Finally, in the continuous presence of DPCPX, SCH58261 caused a significantly larger inhibition of LTP amplitude in aged (-71 ± 45%) than middle-aged (-28 ±9%) or young rats (-11 ± 2%). Accordingly, aged rats displayed an increased expression of A(₂A) R mRNA in the hippocampus and a higher number of glutamatergic nerve terminals equipped with A(2A) R in aged (67 ± 6%) compared with middle-aged (34 ± 7%) and young rats (25 ± 5%). The results show an enhanced A(₂A) R-mediated modulation of LTP in aged rats, in accordance with the age-associated increased expression and density of A(₂A) R in glutamatergic terminals. This age-associated gain of function of A(₂A) R modulating synaptic plasticity may underlie the ability of A(₂A) R antagonists to prevent memory dysfunction in aged animals.

Most inherited mitochondrial diseases in infants result from mutations in nuclear genes encoding proteins with specific functions targeted to the mitochondria rather than primary mutations in the mitochondrial DNA (mtDNA) itself. In the past decade, a growing number of syndromes associated with dysfunction resulting from tissue-specific depletion of mtDNA have been reported in infants. MtDNA depletion syndrome is transmitted as an autosomal recessive trait and causes respiratory chain dysfunction with prominent neurological, muscular, and hepatic involvement. Mendelian diseases characterized by defective mitochondrial protein synthesis and combined respiratory chain defects have also been described in infants and are associated with mutations in nuclear genes that encode components of the translational machinery. In the present work, we reviewed current knowledge of clinical phenotypes, their relative frequency, spectrum of mutations, and possible pathogenic mechanisms responsible for infantile disorders of oxidative metabolism involved in correct mtDNA maintenance and protein production.

Livro de abstracts da 16ª reunião da SPGH - 2012 Introduction Sensorineural hearing loss (SNHL) is one of the most common disabilities in human, and genetics is an important aspect in research and clinical practice for SNHL. One in 1000 children is born with bilateral SNHL, and 50-70% of them have monogenic causes for their deafness. Hereditary hearing loss can be classified into syndromic and nonsyndromic depending on the associated features. Whilst over 400 genetic syndromes have been described in association with mono- or bilateral deafness, syndromic conditions account for about 30% of hereditary congenital hearing loss whereas the relative contribution to all deaf people is much higher (>70%) for nonsyndromic subtypes. The understanding of the molecular genetics in SNHL has advanced rapidly during the last decade but the molecular etiology of hearing impairment in the Portuguese population has not been investigated thoroughly. Methods We analyzed the whole mitochondrial genome in 95 unrelated children with SNHL (53 non-syndromic and 42 syndromic) and searched for variations in two frequent mutated genes, GJB2 and GJB6, in the non-syndromic patients. Results Mutations in mtDNA were detected in 4.2% of the cases, including a hitherto undescribed change in the mtDNA-tRNATrp gene (namely, m.5558A>G). We also identified mono- or bi-allelic GJB2 mutations in 20 of 53 non-syndromic cases and also detected two novel mutations (p.P70R and p.R127QfsX84). Discussion Our data suggest that analysis of the GJB2 gene may have clinical implications in the diagnosis of deaf Portuguese children. Also, it would make feasible early rehabilitation and prevention in affected families. The relatively higher incidence of mtDNA mutation also suggests that screening for variations in the mitochondrial genome should always be considered unless mitochondrial inheritance can be excluded for certain. The molecular diagnosis will permit more accurate genetic counseling for family members, monitor possible multisystem complications, and avoid usage of aminoglycosides if infections occur.

L-2-hydroxyglutaric aciduria (L-2-HGA, MIM 236792) is a neurometabolic disorder caused by the toxic accumulation of high concentration of L-2-hydroxyglutaric acid in plasma and cerebrospinal fluid. Distinct mutations on the L2HGDH gene have been associated with the clinical and biochemical phenotype. Here we present three novel mutations (Gln197X, Gly211Val and c.540+1 G>A), which increase the present deleterious collection of L2HGDH gene up to 35 mutations that we have compiled in this study. In addition, we used the haplotypic information based on polymorphic markers to demonstrate the common origin of Gly57Arg harboring chromosomes.

Strains TRF-1(T) and TC-9 were isolated from transfer spikes of two separate bottles containing 0.9 % NaCl (physiological saline) solution used repeatedly to wash wounds in hospital wards, months apart. Phylogenetic analysis of 16S rRNA gene sequences revealed that strains TRF-1(T) and TC-9 formed a distinct branch within the family Bacillaceae most closely related to the members of the genus Jeotgalicoccus. The two strains, with identical 16S rRNA gene sequences, showed sequence similarities of 89.8-93.9 % with species of Jeotgalicoccus, 91.1-91.8 % with species of Salinicoccus and 89.1-89.7 % with species of Staphylococcus. Strains TRF-1(T) and TC-9 are Gram-positive, non-spore-forming and non-motile cocci, with an optimum growth temperature of about 37 degrees C. Strain TRF-1(T) grew optimally in medium containing 3 % (w/v) NaCl (maximum about 14 % NaCl), while strain TC-9 grew optimally in medium with 1 % (w/v) NaCl. Both strains produce a brown pigment when grown in the presence of NaCl. The cell-wall peptidoglycan is of the A3alpha type with a cross-linkage containing the peptide l-Lys-Gly(4)-l-Ser-Gly. The major respiratory quinones are menaquinone 7 (MK-7) and menaquinone 8 (MK-8), the major fatty acids are straight-chain C(14 : 0) and C(16 : 0) (more than 85 % of the total) and the major polar lipid is an unknown aminophospholipid. The DNA G+C content is 33.5 mol%. On the basis of the phylogenetic analysis and physiological and biochemical characteristics, we are of the opinion that strains TRF-1(T) and TC-9 represent a novel species of a new genus, for which we propose the name Nosocomiicoccus ampullae gen. nov., sp. nov. The type strain of Nosocomiicoccus ampullae is strain TRF-1(T) (=LMG 24060(T) =CIP 109506(T)).

Mucopolysaccharidosis type IIIB (Sanfilippo B disease) is a rare autosomal recessive disorder caused by defective alpha-N-acetylglucosaminidase (NAGLU). We examined the NAGLU gene in 11 MPS IIIB Portuguese patients, having identified five novel (M1K, W147X, G304V, S522P, and R533X) and four previously reported mutations (W168X, R234C, R565W and R643C). R234C attained the high prevalence of 32% of the mutated alleles. Because R234C had already been reported to be common in Spanish patients, a haplotypic analysis was conducted to address the question of its origin in the Iberian Peninsula. Three neutral markers were studied that allowed for the identification of the probable founder haplotype (174-234-G) on which R234C arose. The sharing of the ancestral haplotype by Portuguese and Spanish patients clearly implied a common origin of the mutation in Iberia, through an event that was inferred to have been rather recent. Therefore, the reconstructed history of R234C explains the high incidence of the mutation in Iberian patients with Sanfilippo B disease.

In the hippocampus, impaired neurophysiology, compromised neurogenesis, and eventually apoptosis accompany cognitive deficits in insulinopenic (type-1) diabetes (T1D). The underlying pathological mechanisms remain to be defined. The hippocampus has a high density of the cannabinoid type 1 receptor (CB1R), which has been shown to control several brain functions affected by diabetes, such as synaptic plasticity, glucose utilisation, memory consolidation and cognition, and maturation and survival of hippocampal neurons. However, the role of this receptor has not been investigated yet in diabetic encephalopathy. We report now that in the streptozotocin animal model of T1D, the hippocampal densities of CB1R protein and of specific CB1R binding sites are significantly increased both in the nerve terminals and in total membranes (changes between 13% and 38%), whereas CB1R mRNA expression is decreased by 25%, suggesting that CB1Rs might play a role in diabetic encephalopathy. http://www.sciencedirect.com/science/article/B6WFG-4MSY8KB-1/1/f6aea3c2bf8969bbc4a66f55cda209a9

Publicado em: Livro de abstracts do congresso UMDF - 2012 Defects of mitochondrial complex III (CIII) are a relatively rare cause of mitochondrial dysfunction. CIII or ubiquinol-cytochrome c reductase is the third component of the mitochondrial respiratory chain and catalyzes the electrons transfer from reduced coenzyme Q to cytochrome c and is composed of 11 subunits; one encoded by mitochondrial DNA (MT-CYB) and the remaining by nuclear genes. BCS1L gene is a CIII assembly factor. Mutations in MT-CYB and BCS1L genes account for the vast majority of mutations leading to CIII deficiency, and are associated with a wide range of neuromuscular disorders. The human tetratricopeptide 19 (TTC19), encodes a poorly understood member of tetratricopeptide repeat domain 19 located on chromosome 17 and appears 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. Here we present a consanguineous Portuguese family where a severe biochemical deficiency of complex III enzyme activity occurred in four siblings in association with neurological manifestations suggestive of cerebellar ataxia combined with relentless psychiatric manifestations. Variability in age at onset and disease course was associated with a novel homozygous mutation in TTC19. We had first detected a biochemically deficient enzyme activity in the family, we had analyzed all structural genes part of CIII as well as BCS1L. Only the recent description of mutations in TTC19 raised high the suspect of a similar condition in the present family. The novel TTC19 mutation identified in this family, was homozygous in the four patients, heterozygous in their parents and in two healthy relatives, and it was absent in ethnically-matched controls. The mutation predicts a frameshift, resulting in a truncated protein by the insertion of a premature stop codon. In summary, we are describing the 4th family identified in the world carrying a novel TTC19 mutation. Our data corroborate the genotype and phenotype variability presented by the affected family members and hopefully will contribute to a deeper understanding of the CIII-related disorders.