RESUMO
Identification of the novel HLA-C*02:10:09 allele that differs from HLA-C*02:10:01:01 at one position in exon 1.
Assuntos
Genes MHC Classe I , Antígenos HLA-C , Humanos , Antígenos HLA-C/genética , Brasil , Alelos , Éxons/genéticaRESUMO
INTRODUCTION: In Colombia, thyroid cancer ranks among the highest incidences, yet our population lacks studies on its molecular profile. This study aims to characterize clinical, histopathologic and molecular data in a Colombian cohort with papillary thyroid carcinoma (PTC). METHODS: A retrospective review of clinical history, clinicopathologic characteristics, treatment and 5-10-year follow-up for all patients was done. DNA and RNA were extracted from formalin-fixed paraffin-embedded (FFPE) tissue using the Quick-DNA & RNA FFPE Min iPrep kit (Zymo Research). Next-generation sequencing (NGS) analysis was performed with SOPHiA Solid Tumor Solutions kit (SOPHiA GENETICS). Tumor mutation genomic analysis used SOPHiA DDM™ platform, with descriptive analysis reporting frequencies, means and associations via chi-square analysis. RESULTS: Among 231 sequenced patients, mean age at diagnosis was 46 (± 12.35) years, with higher frequency in women (81.82%). Two cases were reclassified as non-invasive follicular thyroid neoplasm (NIFT-P); an NRAS mutation was found in one of them. Predominant histologic subtype was classic PTC (57.64%) followed by tall cell (28.82%). Of the 229 sequenced carcinomas, mutations were identified in 186 cases, including BRAF, IDH1, RAS and PIK3CA. Notable copy number variations (CNVs) were PDGFRA, CDK4 and KIT, with RET being the most frequent gene fusion, including CCDC6-RET in two classic subtype cases. CONCLUSION: This is the first study in Colombia (TIROSEC) to our knowledge that integrates molecular and histopathologic profiles enriching our local comprehension and knowledge of PTC. The identification of target mutations such as BRAF, RET and NTRK fusions holds the potential to guide targeted therapies for tumor recurrence and predict aggressive behavior.
Assuntos
Carcinoma Papilar , Neoplasias da Glândula Tireoide , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Câncer Papilífero da Tireoide/genética , Colômbia , Proteínas Proto-Oncogênicas B-raf/genética , Variações do Número de Cópias de DNA , Carcinoma Papilar/genética , Recidiva Local de Neoplasia , Neoplasias da Glândula Tireoide/genética , Mutação , DNA , RNARESUMO
Use of the potent tyrosine kinase inhibitor imatinib as the first-line treatment in chronic myeloid leukemia (CML) has decreased mortality from 20% to 2%. Approximately 30% of CML patients experience imatinib resistance, however, largely because of point mutations in the kinase domain of the BCR-ABL1 fusion gene. The aim of this study was to use next-generation sequencing (NGS) to identify mutations related to imatinib resistance. The study included 22 patients diagnosed with CML and experiencing no clinical response to imatinib. Total RNA was used for cDNA synthesis, with amplification of a fragment encompassing the BCR-ABL1 kinase domain using a nested-PCR approach. Sanger and NGS were applied to detect genetic alterations. HaplotypeCaller was used for variant calling, and STAR-Fusion software was applied for fusion breakpoint identification. After sequencing analysis, F311I, F317L, and E450K mutations were detected respectively in three different participants, and in another two patients, single nucleotide variants in BCR (rs9608100, rs140506, rs16802) and ABL1 (rs35011138) were detected. Eleven patients carried e14a2 transcripts, nine had e13a2 transcripts, and both transcripts were identified in one patient. One patient had co-expression of e14a2 and e14a8 transcripts. The results identify candidate single nucleotide variants and co-expressed BCR-ABL1 transcripts in cellular resistance to imatinib.
Assuntos
Proteínas de Fusão bcr-abl , Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Mesilato de Imatinib/uso terapêutico , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Nucleotídeos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genéticaRESUMO
The CS21 pilus produced by enterotoxigenic Escherichia coli (ETEC) is involved in adherence to HT-29 intestinal cells. The CS21 pilus assembles proteins encoded by 14 genes clustered into the lng operon. AIM: This study aimed to determine whether E. coli BL21 (ECBL) transformed with the lng operon lacking the lngA gene (pE9034AΔlngA) and complemented in trans with lngA variants of ETEC clinical strains, as well as point substitutions, exhibited modified adherence to HT-29 cells. METHODS: A kanamycin cassette was used to replace the lngA gene in the lng operon of the E9034A strain, and the construct was transformed into the ECBL strain. The pJET1.2 vector carrying lngA genes with allelic variants was transformed into ECBLpE9034AΔlngA (ECBLΔlngA). The point substitutions were performed in the pJETlngAFMU073332 vector. RESULTS: Bioinformatic alignment analysis of the LngA proteins showed hypervariable regions and clustered the clinical ETEC strains into three groups. Variations in amino acid residues affect the adherence percentages of recombinant ECBL strains with lngA variants and site-specific mutations with HT-29 cells. CONCLUSION: In this study, ECBL carrying the lng operon harboring lngA variants of six clinical ETEC strains, as well as point substitutions, exerted an effect on the adherence of ECBL to HT-29 cells, thereby confirming the importance of the CS21 pilus in adherence.
RESUMO
RESUMEN Objetivo. Determinar la estructura genética de las cepas drogorresistentes de Mycobacterium tuberculosis que circularon en todo el Perú durante los años 2011-2015 a través de haplotipos obtenidos de un ensayo con sondas en línea. Materiales y métodos. Se analizaron 6589 muestras que ingresaron al Instituto Nacional de Salud para el diagnóstico rutinario mediante el ensayo GenoType® MTBDRplus v2, durante el periodo de estudio. Se crearon haplotipos resistentes mediante la concatenación de 21 sitios polimórficos de los genes evaluados por el ensayo con sondas en línea, y se realizó el análisis de asociación con fenotipos obtenidos por el método de proporciones agar 7H10. Resultados. Las mutaciones de mayores frecuencias fueron: rpoB S531L (55,4%) y rpoB D516V (18,5%) para la resistencia a rifampicina, y katG S315T (59,5%) e inhA c-15t (25,7%) para la resistencia a isoniacida. Se obtuvieron 13 haplotipos representativos (87,8% de muestras analizadas) de los cuales seis correspondieron al genotipo multidrogorresistente, cuatro al genotipo monorresistente a isoniacida y tres al genotipo monorresistente a rifampicina. Dieciocho departamentos, y la provincia del Callao, presentaron una alta diversidad haplotípica; cuatro presentaron moderada diversidad y dos presentaron baja diversidad. Conclusiones. Existe una alta diversidad haplotípica en la mayoría de los departamentos, además de una concentración de las cepas de Mycobacterium tuberculosis drogorresistentes en las ciudades de Lima y Callao. Asimismo, las cepas de Mycobacterium tuberculosis con perfil drogorresistente que circulan en el Perú contienen principalmente los marcadores genéticos de mayor prevalencia a nivel mundial asociados con la resistencia frente a rifampicina e isoniacida.
ABSTRACT Objective. To determine the genetic structure of drug-resistant strains of Mycobacterium tuberculosis that circulated throughout Peru during the years 2011-2015, by using haplotypes obtained from a line probe assay. Materials and methods. A total of 6589 samples that were admitted to the Instituto Nacional de Salud for routine diagnosis using the GenoType® MTBDRplus v2 assay were analyzed during the study period. Resistant haplotypes were created by concatenating 21 polymorphic sites of the evaluated genes using the line probe assay; and the association analysis was carried out with phenotypes obtained by the 7H10 agar ratio method. Results. The most frequent mutations were: rpoB S531L (55.4%) and rpoB D516V (18.5%) for rifampicin resistance, and katG S315T (59.5%) and inhA c-15t (25.7%) for isoniazid resistance. We obtained 13 representative haplotypes (87.8% of analyzed samples), 6 corresponded to the multidrug-resistant genotype, 4 to the isoniazid mono-resistant genotype and 3 to the rifampicin mono-resistant genotype. Eighteen regions and the province of Callao showed high haplotype diversity; four showed moderate diversity and two showed low diversity. Conclusions. Most regions showed high haplotype diversity; in addition, most drug-resistant strains of Mycobacterium tuberculosis were concentrated in the cities of Lima and Callao. Likewise, drug-resistant Mycobacterium tuberculosis strains circulating in Peru mainly contain the genetic markers with the highest prevalence worldwide, which are associated with resistance to rifampicin and isoniazid.
Assuntos
Tuberculose , Haplótipos , Resistência a Medicamentos , Mycobacterium tuberculosis , Peru , Variação Genética , DNA Bacteriano , Mutação Puntual , Epidemiologia Molecular , Técnicas de Diagnóstico Molecular , Serviços Laboratoriais de Saúde Pública , GenótipoRESUMO
The prediction of peptide binders to Major Histocompatibility Complex (MHC) class II receptors is of great interest to study autoimmune diseases and for vaccine development. Most approaches predict the affinities using sequence-based models trained on experimental data and multiple alignments from known peptide substrates. However, detecting activity differences caused by single-point mutations is a challenging task. In this work, we used interactions calculated from simulations to build scoring matrices for quickly estimating binding differences by single-point mutations. We modelled a set of 837 peptides bound to an MHC class II allele, and optimized the sampling of the conformations using the Rosetta backrub method by comparing the results to molecular dynamics simulations. From the dynamic trajectories of each complex, we averaged and compared structural observables for each amino acid at each position of the 9°mer peptide core region. With this information, we generated the scoring-matrices to predict the sign of the binding differences. We then compared the performance of the best scoring-matrix to different computational methodologies that range in computational costs. Overall, the prediction of the activity differences caused by single mutated peptides was lower than 60% for all the methods. However, the developed scoring-matrix in combination with existing methods reports an increase in the performance, up to 86% with a scoring method that uses molecular dynamics.
RESUMO
Identification of the novel HLA-B*15:554 allele that differs from HLA-B*15:01:01 at one position in exon 3.
Assuntos
Genes MHC Classe I , Antígenos HLA-B , Alelos , Brasil , Éxons/genética , Antígenos HLA-B/genética , Sequenciamento de Nucleotídeos em Larga Escala , HumanosRESUMO
Identification of the novel HLA-B*15:555 allele that differs from HLA-B*15:17:01 at one position in exon 2.
Assuntos
Genes MHC Classe I , Antígenos HLA-B , Alelos , Brasil , Éxons/genética , Antígenos HLA-B/genética , HumanosRESUMO
Objetivo: Analisar as implicações, impactos e o desenvolvimento de um indivíduo diagnosticado com TEA e portador da mutação de novo no gene DEAF1, a partir das várias perspectivas de intervenções realizadas. Método: Trata-se de um estudo descritivo com histórico dos tratamentos, resultados laboratoriais e genéticos mais recentes do paciente. Resultados: Sintomas notados aos 2 anos e diagnóstico específico aos 5. Aos 8 anos teve a primeira crise convulsiva tônico-clônica e o Eletroencefalograma alterado. Após obteve o diagnóstico molecular confirmado. Possuía epilepsia refratária de difícil controle, que houve piora com uma tentativa do uso de derivados canabinoides em conjunto com estimulação elétrica transcraniana. No momento, com os tratamentos, atendimentos multidisciplinares, dieta de exclusão de alérgenos e medicações de controle individual, diminuíram a intensidade das crises epiléticas e houve melhor controle do seu estado geral. Conclusão: Este estudo descreve como a mutação de novo no gene DEAF1 está relacionada com o TEA e com o comprometimento do desenvolvimento neurocognitivo. As terapias e métodos devem respeitar cada paciente na sua individualidade.
Objective: To analyze the implications, impacts and development of an individual diagnosed with ASD and carrying a de novo mutation in the DEAF1 gene, from the various perspectives of interventions performed. Method: This is a descriptive study, with the patient's history of treatments, and most recent laboratory and genetic results.Results: Symptoms were noticed at 2 years old and specific diagnosis at 5. At 8 years old he had his first tonic-clonic seizure and the electroencephalogram was altered. After, it was obtained the confirmed molecular diagnosis. He had refractory epilepsy that was difficult to control and aggravated with an attempt to use cannabinoid derivatives in conjunction with transcranial electrical stimulation. At the moment, treatments, multidisciplinary care, allergen exclusion diet and individual control medications, reduced the intensity of epileptic seizures and there was better control of his general condition. Conclusion: This study describes how the de novo mutation in the DEAF1 gene is related to ASD and neurocognitive development impairment. Therapies and methods must respect each patient in their individuality.
Objetivo: Analizar las implicaciones, impactos y desarrollo de un individuo diagnosticado de TEA y portador de una mutación de novo en el gen DEAF1, desde las distintas perspectivas de las intervenciones realizadas. Método: Este es un estudio descriptivo, con el historico de tratamientos del paciente y los resultados genéticos y de laboratorio más recientes. Resultados: Los síntomas se notaron a los 2 años y el diagnóstico específico a los 5. A los 8 años tuvo su primera crisis tónico-clónica y se alteró el electroencefalograma. Posteriormente se obtuvo el diagnóstico molecular confirmado. Tenía epilepsia refractaria que era difícil de controlar y se agravaba con un intento de utilizar derivados cannabinoides junto con estimulación eléctrica transcraneal. En el momento, los tratamientos, la atención multidisciplinar, la dieta de exclusión de alérgenos y los medicamentos de control individual, redujeron la intensidad de las crisis epilépticas y hubo un mejor control de su estado general. Conclusión: Este estudio describe cómo la mutación de novo en el gen DEAF1 se relaciona con el TEA y el deterioro del desarrollo neurocognitivo. Las terapias y los métodos deben respetar a cada paciente en su individualidad.
Assuntos
Humanos , Cromossomos Humanos , Mutação Puntual , Transtorno do Espectro AutistaRESUMO
Identification of the novel HLA-C*15:02:43 allele that differs from HLA-C*15:02:01 at one position in exon 4.
Assuntos
Genes MHC Classe I , Antígenos HLA-C , Alelos , Brasil , Éxons/genética , Antígenos HLA-C/genética , HumanosRESUMO
Identification of the novel HLA-B*42:02:02 allele that differs from HLA-B*42:02:01 at one position in exon 4.
Assuntos
Genes MHC Classe I , Antígenos HLA-B , Alelos , Brasil , Éxons/genética , Antígenos HLA-B/genética , HumanosRESUMO
Identification of the novel HLA-C*14:02:34 allele that differs from HLA-C*14:02:01 at one position in exon 1.
Assuntos
Genes MHC Classe I , Antígenos HLA-C , Alelos , Brasil , Éxons/genética , Antígenos HLA-C/genética , HumanosRESUMO
Identification of the novel HLA-C*07:93:02 allele that differs from HLA-C*07:93:01 at one position in exon 5.
Assuntos
Genes MHC Classe I , Antígenos HLA-C , Alelos , Brasil , Éxons/genética , Antígenos HLA-C/genética , HumanosRESUMO
Advancements in genetically modified herbicide tolerance technology opened a new way to manage weed populations in crop fields. Since then, many important genetically modified crops that are tolerant to various herbicides have been developed and commercialized. Herbicides primarily act by disrupting key enzymes involved in essential metabolic or physiological processes associated with growth and development of plants. Most of the herbicide tolerant plants have been developed by introducing point mutations (non-GM approach) in the target site of herbicide action, due to the advantage of easier registration/release for commercial cultivation as well as wider public acceptance. Of the various herbicides, Imidazolinones are probably the most widely targeted ones for developing herbicide tolerant crops through non-GM approach. In rice, different mutant lines presenting amino acids changes in acetolactate synthase (ALS) have the ability to tolerate different Imidazolinones, including point mutations of Glycine to Glutamate in position 628, Serine to Asparagine in position 627, and a double mutation Tryptophan to Leucine in position 548/Serine to Isoleucine in position 627. The use of specific herbicides in combination of these mutant lines provides a reliable approach to eliminate weeds in the fields. However, the continuous overuse of a single herbicide multiple times in a growing season increases the potential risk of evolution of resistant weeds, which has become a major concern in agriculture worldwide. For this reason, the development of novel mutations in ALS (Os02g30630) to generate rice plants more tolerant to Imidazolinones than the available mutant rice lines is still a hot topic in plant-herbicide interaction field. Keeping that in mind, we carried out molecular docking experiments of Imidazolinone herbicides imazapic, imazapyr, imazaquin, and imazethapyr to evaluate the interaction of these molecules in the binding cavity of ALS from rice, being able to identify the most important amino acids responsible for the stability of these four herbicides. After introducing point mutations in these specific positions (one at a time) using Alanine scanning mutagenesis method and recalculating the effect in the affinity of herbicide-ALS interaction, we were able to propose novel amino acid residues (mainly Lysine in position 230 and Arginine in position 351) on the structure of ALS presenting a highest impact in the binding of Imidazolinones to ALS when compared to the already known amino acid mutations. This rational approach allows the researcher/farmer to choose the number of point mutations to be inserted in a rice cultivar, which will be dependent on the type of Imidazolinone used. To obtain a rice cultivar capable to tolerate the four Imidazolinone tested at the same time, we suggest six amino acid mutations at positions Val170, Phe180, Lys230, Arg351, Trp548, and Ser627 in the OsALS1.
RESUMO
The genus Colletotrichum comprises species with different lifestyles but is mainly known for phytopathogenic species that infect crops of agronomic relevance causing considerable losses. The fungi of the genus Colletotrichum are distributed in species complexes and within each complex some species have particularities regarding their lifestyle. The most commonly found and described lifestyles in Colletotrichum are endophytic and hemibiotrophic phytopathogenic. Several of these phytopathogenic species show wide genetic variability, which makes long-term maintenance of resistance in plants difficult. Different mechanisms may play an important role in the emergence of genetic variants but are not yet fully understood in this genus. These mechanisms include heterokaryosis, a parasexual cycle, sexual cycle, transposable element activity, and repeat-induced point mutations. This review provides an overview of the genus Colletotrichum, the species complexes described so far and the most common lifestyles in the genus, with a special emphasis on the mechanisms that may be responsible, at least in part, for the emergence of new genotypes under field conditions.
Assuntos
Colletotrichum/crescimento & desenvolvimento , Colletotrichum/genética , Variação Genética/genética , Doenças das Plantas/microbiologia , Elementos de DNA Transponíveis/genética , Endófitos , Genoma Fúngico/genética , Especificidade de Hospedeiro , Sequências Repetitivas de Ácido Nucleico/genética , Especificidade da EspécieRESUMO
Infections caused by multidrug-resistant Pseudomonas aeruginosa in hospitalized patients are often fatal, and nosocomial infections caused by Guiana extended-spectrum (GES) ß-lactamase-producing strains are of growing concern. Several genotypes of the GES ß-lactamase gene (bla GES) include a single missense mutation, a change from G to A at nucleotide position 493 (G493A) that changes glycine to serine; the mutant enzyme exhibits carbapenemase activity. Rapid and reliable identification of drug-resistance is important in clinical settings; however, culture methods remain the gold standard. Conventional and real-time PCR cannot identify carbapenemase-producing genotypes, and direct DNA sequencing is essential. We established a novel loop-mediated isothermal amplification (LAMP) method to detect various genotypes of bla GES and another LAMP method to discriminate carbapenemase genotypes of bla GES. We evaluated the two assays using clinical P. aeruginosa strains. Two primer sets targeting bla GES (GES-LAMP) and the point mutation (Carba-GES-LAMP) were designed and evaluated for specificity and sensitivity. The detection limit of the GES-LAMP method was assessed using purified DNA and DNA-spiked clinical samples (urine, sputum, and blood). To determine the clinical usefulness of the methods, we used different (genotypically and phenotypically) P. aeruginosa clinical isolates, collected from diverse geographical locations between 2003 and 2012. The novel LAMP assay targeting bla GES was highly specific. The detection limit was 10 DNA copies per reaction; the assay was 10-fold more sensitive than conventional PCR. The LAMP assay detected bla GES with high sensitivity in all DNA-spiked samples; PCR did not detect bla GES in blood samples. The GES-LAMP method correctly detected the 5 isolates containing bla GES among the 14 isolates tested. Using these isolates, we confirmed that our Carba-GES-LAMP method of detecting point mutations correctly identified the two bla GES positive organisms with carbapenemase activity. To the best of our knowledge, this is the first report of the GES ß-lactamase gene detection assay using the LAMP method. Our new assays effectively detect bla GES and critical unique mutations.
RESUMO
Voltage-gated potassium (KV) channels regulate diverse physiological processes and are an important target for developing novel therapeutic approaches. Sea anemone (Cnidaria, Anthozoa) venoms comprise a highly complex mixture of peptide toxins with diverse and selective pharmacology on KV channels. From the nematocysts of the sea anemone Actinia bermudensis, a peptide that we named AbeTx1 was purified and functionally characterized on 12 different subtypes of KV channels (KV1.1â»KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; KV11.1; and, Shaker IR), and three voltage-gated sodium channel isoforms (NaV1.2, NaV1.4, and BgNaV). AbeTx1 was selective for Shaker-related K⺠channels and is capable of inhibiting K⺠currents, not only by blocking the K⺠current of KV1.2 subtype, but by altering the energetics of activation of KV1.1 and KV1.6. Moreover, experiments using six synthetic alanine point-mutated analogs further showed that a ring of basic amino acids acts as a multipoint interaction for the binding of the toxin to the channel. The AbeTx1 primary sequence is composed of 17 amino acids with a high proportion of lysines and arginines, including two disulfide bridges (Cys1â»Cys4 and Cys2â»Cys3), and it is devoid of aromatic or aliphatic amino acids. Secondary structure analysis reveals that AbeTx1 has a highly flexible, random-coil-like conformation, but with a tendency of structuring in the beta sheet. Its overall structure is similar to open-ended cyclic peptides found on the scorpion κ-KTx toxins family, cone snail venoms, and antimicrobial peptides.
Assuntos
Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Anêmonas-do-Mar/química , Anêmonas-do-Mar/metabolismo , Toxinas Biológicas/química , Toxinas Biológicas/farmacologia , Sequência de Aminoácidos , Aminoácidos/metabolismo , Animais , Venenos de Cnidários/química , Venenos de Cnidários/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Potássio/metabolismo , Bloqueadores dos Canais de Potássio/química , Bloqueadores dos Canais de Potássio/farmacologia , Alinhamento de SequênciaRESUMO
AIM: To characterize punctual mutations in 23S rRNA gene of clarithromycin-resistant Helicobacter pylori (H. pylori) and determine their association with therapeutic failure. METHODS: PCR products of 23S rRNA gene V domain of 74 H. pylori isolates; 34 resistant to clarithromycin (29 from a low-risk gastric cancer (GC) population: Tumaco-Colombia, and 5 from a high-risk population: Tuquerres-Colombia) and 40 from a susceptible population (28 from Tumaco and 12 from Túquerres) were sequenced using capillary electrophoresis. The concordance between mutations of V domain 23S rRNA gene of H. pylori and therapeutic failure was determined using the Kappa coefficient and McNemar's test was performed to determine the relationship between H. pylori mutations and clarithromycin resistance. RESULTS: 23S rRNA gene from H. pylori was amplified in 56/74 isolates, of which 25 were resistant to clarithromycin (20 from Tumaco and 5 from Túquerres, respectively). In 17 resistant isolates (13 from Tumaco and 4 from Túquerres) the following mutations were found: A1593T1, A1653G2, C1770T, C1954T1, and G1827C in isolates from Tumaco, and A2144G from Túquerres. The mutations T2183C, A2144G and C2196T in H. pylori isolates resistant to clarithromycin from Colombia are reported for the first time. No association between the H. pylori mutations and in vitro clarithromycin resistance was found. However, therapeutic failure of eradication treatment was associated with mutations of 23S rRNA gene in clarithromycin-resistant H. pylori (κ = 0.71). CONCLUSION: The therapeutic failure of eradication treatment in the two populations from Colombia was associated with mutations of the 23S rRNA gene in clarithromycin-resistant H. pylori.
Assuntos
Antibacterianos/uso terapêutico , Claritromicina/uso terapêutico , Dispepsia/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/genética , RNA Ribossômico 23S/genética , Adulto , Biópsia , Colômbia/epidemiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Dispepsia/epidemiologia , Dispepsia/microbiologia , Dispepsia/patologia , Feminino , Mucosa Gástrica/patologia , Genes de RNAr/genética , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Mutação Puntual , Prevalência , Análise de Sequência de DNA , Falha de TratamentoRESUMO
ABSTRACT Hereditary hyperferritinemia-cataract syndrome is an autosomal dominant genetic disorder associated with mutations in the 5'UTR region of the ferritin light chain gene. These mutations cause the ferritin levels to increase even in the absence of iron overload. Patients also develop bilateral cataract early due to accumulation of ferritin in the lens, and many are misdiagnosed as having hemochromatosis and thus not properly treated. The first cases were described in 1995 and several mutations have already been identified. However, this syndrome is still a poorly understood. We report two cases of unrelated Brazilian families with clinical suspicion of the syndrome, which were treated in our department. For the definitive diagnosis, the affected patients, their parents and siblings were submitted to Sanger sequencing of the 5'UTR region for detection of the ferritin light gene mutation. Single nucleotide polymorphism-like mutations were found in the affected patients, previously described. The test assisted in making the accurate diagnosis of the disease, and its description is important so that the test can be incorporated into clinical practice.
RESUMO A síndrome hereditária hiperferritinemia-catarata é uma doença genética autossômica dominante associada a mutações na região 5'UTR do gene da cadeia leve da ferritina. Estas mutações elevam os níveis de ferritina, mesmo na ausência de sobrecarga de ferro. Os pacientes também desenvolvem catarata bilateral precocemente, devido ao acúmulo de ferritina no cristalino, e muitos são erroneamente diagnosticados como portadores de hemocromatose, sendo tratados de maneira inadequada. Os primeiros casos foram descritos em 1995, e diversas mutações já foram identificadas. Entretanto, essa síndrome ainda é pouco conhecida. Relatamos dois casos de famílias brasileiras, não relacionadas, com suspeita clínica da síndrome, que foram atendidas em nosso serviço. Para o diagnóstico definitivo, os pacientes afetados, seus pais e irmãos foram submetidos à pesquisa de mutação do gene ferritina, por sequenciamento de Sanger da região 5'UTR. Foram encontradas mutações do tipo polimorfismo de nucleotídeo único nos pacientes afetados, já descritas anteriormente. O teste auxiliou no diagnóstico preciso da doença e é importante ser divulgado, para ser incorporado na prática clínica.
Assuntos
Humanos , Masculino , Pré-Escolar , Criança , Apoferritinas/sangue , Catarata/congênito , Distúrbios do Metabolismo do Ferro/congênito , Ferro/sangue , Síndrome , Catarata/genética , Catarata/sangue , Brasil , Distúrbios do Metabolismo do Ferro/genética , Distúrbios do Metabolismo do Ferro/sangue , Mutação/genéticaRESUMO
Farnesyl diphosphate synthase (FPPS) is a key enzyme responsible for the supply of isoprenoid precursors for several essential metabolites, including sterols, dolichols and ubiquinone. In Saccharomyces cerevisiae, FPPS catalyzes the sequential condensation of two molecules of isopentenyl diphosphate (IPP) with dimethylallyl diphosphate (DMAPP), producing geranyl diphosphate (GPP) and farnesyl diphosphate (FPP). Critical amino acid residues that determine product chain length were determined by a comparative study of strict GPP synthases versus strict FPPS. In silico ΔΔG, i.e. differential binding energy between a protein and two different ligands-of yeast FPPS mutants was evaluated, and F96, A99 and E165 residues were identified as key determinants for product selectivity. A99X variants were evaluated in vivo, S. cerevisiae strains carrying A99R and A99H variants showed significant differences on GPP concentrations and specific growth rates. The FPPS A99T variant produced unquantifiable amounts of FPP and no effect on GPP production was observed. Strains carrying A99Q, A99Y and A99K FPPS accumulated high amounts of DMAPP-IPP, with a decrease in GPP and FPP. Our results demonstrated the relevance of the first residue before FARM (First Aspartate Rich Motif) over substrate consumption and product specificity of S. cerevisiae FPPS in vivo. The presence of A99H significantly modified product selectivity and appeared to be relevant for GPP synthesis.