Factores genéticos asociados a long COVID / Genetic factors associated with long COVID

Introducción: La variabilidad de la expresión y la evolución de la COVID no se explican completamente por los factores clínicos, atribuyéndose un importante papel a los genéticos. Además, se ha planteado si los mismos componentes genéticos que participan en la susceptibilidad y gravedad de la infección influyen en su evolución hacia long COVID. Como objetivo nos propusimos revisar la literatura a fin de conocer cuáles son los factores genéticos que intervienen en la génesis de la COVID persistente. Material y métodos: Revisión sistemática en PubMed y repositorios bioRxiv y medRxiv con base en los descriptores y términos Medical Subject Headings (MeSH) relacionados con COVID y factores genéticos. Fueron seleccionados 2.705 artículos. Un primer cribado, realizado de manera independiente por los autores, redujo la lista a 205 y finalmente, tras un análisis más detallado, se eligieron 85 trabajos para su lectura completa y revisión. Resultados: La enzima convertidora de angiotensina 2 (ACE2) y la proteasa transmembrana, serina 6 (TMPSS6) están implicadas en la susceptibilidad, sin embargo, no se ha encontrado su participación en long COVID. Sí se han hallado algunas asociaciones entre genes, que intervienen en la respuesta inflamatoria e inmune, con la gravedad de la enfermedad y el desarrollo de long COVID. La relación más importante se ha observado en el locus FOXP4. Conclusiones: Aunque actualmente la información sobre long COVID es limitada, parece claro que los factores genéticos identificados hasta ahora no justifican la progresión hacia una enfermedad persistente y se debe considerar la participación de otros componentes como la acción poligénica, de genes pleiotrópicos, de la microbiota y de los cambios epigenéticos.(AU)

Introduction: The variability in expression and evolution of COVID is not completely explained by clinical factors. In fact, genetic factors play an important role. Moreover, it is unknown whether the genetic factor that contribute to susceptibility and severity are also involved in the onset and evolution of long-COVID. The objective of this review is to gather information from literature to understand which genetic factors are involved in the onset of persistent COVID. Material and methods: Systematic review in PubMed and bioRxiv and medRxiv repositories based on MeSH-descriptors and MeSH-terms related to COVID and genetic factors. Using these terms 2715 articles were pooled. An initial screening performed by authors independently, selected 205 articles of interest. A final deeper screening a total of 85 articles were chosen for complete reading and summarized in this review. Results: Although ACE2 and TMPSS6 are involved in COVID susceptibility, their involvement in long-COVID has not been found. On the other hand, the severity of the disease and the onset of long-COVID has been associated with different genes involved in the inflammatory and immune response. Particularly interesting has been the association found with the FOXP4 locus. Conclusions: Although studies on long-COVID are insufficient to fully comprehend the cause, it is clear that the current identified genetic factors do not fully explain the progression and onset of long-COVID. Other factors such as polygenic action, pleiotropic genes, the microbiota and epigenetic changes must be considered and studied.(AU)

Genetic variations in tumor-suppressor miRNA-encoding genes and their target genes: focus on breast cancer development and possible therapeutic strategies

MicroRNAs (miRNAs) negatively affect gene expression by binding to their specific mRNAs resulting in either mRNA destruction or translational repression. The aberrant expression of various miRNAs has been associated with a number of human cancer. Oncogenic or tumor-suppressor miRNAs regulate a variety of pathways involved in the development of breast cancer (BC), including cell proliferation, apoptosis, metastasis, cancer recurrence, and chemoresistance. Variations in miRNA-encoding genes and their target genes lead to dysregulated gene expression resulting in the development and progression of BC. The various therapeutic approaches to treat the disease include chemotherapy, radiation therapy, surgical removal, hormone therapy, chemotherapy, and targeted biological therapy. The purpose of the current review is to explore the genetic variations in tumor-suppressor miRNA-encoding genes and their target genes in association with the disease development and prognosis. The therapeutic interventions targeting the variants for better disease outcomes have also been discussed (AU)

Variante rara de RNF213 en adolescente con enfermedad de moyamoya / Rare RNF213 variant in adolescent with moyamoya disease

Introducción: La enfermedad de moyamoya es una enfermedad estenooclusiva progresiva de las principales arterias intracraneales. Los individuos afectados corren el riesgo de sufrir un accidente cerebrovascular hemorrágico o isquémico intracraneal, deterioro cognitivo y retrasos en el desarrollo. Se han identificado varios genes de susceptibilidad. La variante p.R4810K en el gen RNF213 se ha identificado en el 95% de los pacientes con enfermedad de moyamoya familiar. Caso clínico: Presentamos el caso de una adolescente de 15 años que se presentó con quejas principales de disgrafía y falta de coordinación en la mano derecha con dos meses de evolución. La resonancia magnética cerebral reveló varias lesiones isquémicas con diferentes ritmos de evolución y la angiorresonancia magnética mostró múltiples estenosis suboclusivas. En el estudio de las secuencias de las regiones codificantes y de las regiones intrónicas flanqueantes (±8 pb) del gen RNF213, se detectó la variante c.12185G>A, p.(Arg4062Gln) en heterocigosidad en el gen RNF213. Este resultado indica que la paciente es heterocigota para la variante c.12185G>A, p.(Arg4062Gln) en el gen RNF213. La variante detectada ya ha sido descrita en la bibliografía como una variante fundadora en la población asiática, asociada a síndrome de moyamoya. Esta variante está descrita en ClinVar como una variante de significado clínico desconocido. Además, no está descrita en las bases de datos poblacionales (dbSNP, ESP y gnomAD). Conclusión: Hasta donde sabemos, la variante p.(Arg4062Gln) se ha notificado en tres pacientes japoneses con enfermedad de moyamoya y en uno europeo. Por lo tanto, nuestro paciente fue el segundo europeo con enfermedad de moyamoya con esta variante identificada.(AU)

Introduction: Moyamoya disease is a progressive steno-occlusive disease of the major intracranial arteries. Affected individuals are at risk for intracranial hemorrhagic or ischemic stroke, cognitive impairment, and developmental delays. Several susceptibility genes have been identified. The p.R4810K variant in the RNF213 gene has been identified in 95% of patients with familial moyamoya disease. Case report: We present the case of a 15-year-old adolescent girl who presented with chief complaints of dysgraphia, lack of coordination in the right hand, with two months of evolution. Cerebral magnetic resonance imaging revealed several ischemic lesions with different rates of evolution and magnetic resonance angiography showed multiple subocclusive stenoses. In the study of the sequences of the coding regions and intronic flanking regions (±8 bp) of the RNF213 gene, the variant c.12185G>A, p.(Arg4062Gln) was detected in heterozygosity in the RNF213 gene. This result indicates that the patient is heterozygous for the c.12185G>A, p.(Arg4062Gln) variant in the RNF213 gene. The detected variant has already been reported in the literature as a founder variant in the Asian population, associated with moyamoya syndrome. This variant is described in ClinVar as a variant of unknown clinical significance? Furthermore, it is not described in population databases (dbSNP, ESP, gnomAD). Conclusion: To our knowledge, the p.(Arg406262Gln) variant has been reported in three Japanese moyamoya disease patients and one European. Therefore, our patient was the second European moyamoya disease patient with this variant identified.(AU)

Variantes genéticas y actividad enzimática de la citidin desaminasa: relación con la toxicidad a la capecitabina y recomendación de ajuste de las dosis / Genetic variants and enzyme activity in citidin deaminase: Relationship with capecitabine toxicity and recommendation for dose adjustment

Objetivo: la capecitabina es un fármaco antineoplásico utilizado en el tratamiento del cáncer de mama y de colon que puede dar lugar a una toxicidad grave, llegando a ser mortal en algunos pacientes. La variabilidad interindividual de esta toxicidad es debida en gran medida a las variaciones genéticas en los genes diana y las enzimas de metabolismo de este fármaco, como la timidilato sintasa y la dihidropirimidina deshidrogenasa. La enzima citidin desaminasa (CDA), imprescindible en la activación de la capecitabina, también presenta diversas variantes asociadas con un mayor riesgo de toxicidad al tratamiento, aunque su papel como biomarcador aún no está claramente definido. Por ello, nuestro objetivo principal es estudiar la asociación entre la presencia de las variantes genéticas en el gen CDA, su actividad enzimática y el desarrollo de la toxicidad grave en los pacientes tratados con capecitabina, cuya dosis inicial se haya ajustado con base en el perfil genético del gen de la dihidropirimidina deshidrogenasa (DPYD). Método: estudio de cohortes observacional multicéntrico prospectivo, centrado en el análisis de la asociación genotipo-fenotipo de la enzima CDA. Tras la fase experimental, se desarrollará un algoritmo que permita determinar el ajuste necesario de las dosis para disminuir el riesgo de toxicidad del tratamiento en función del genotipo CDA, elaborando una guía clínica para la dosificación de la capecitabina en función de las variantes genéticas en DPYD y CDA. Con base en esta guía, se creará una herramienta bioinformática que genere el informe farmacoterapéutico de manera automática, facilitando la implementación del consejo farmacogenético en la práctica clínica. Esta herramienta proporcionará un gran respaldo en la toma de decisiones farmacoterapéuticas basadas en el perfil genético del paciente, incorporando la medicina de precisión en la rutina clínica. ... (AU)

Objective: Capecitabine, an antineoplastic drug used in the treatment of breast and colon cancer, can cause severe, even fatal toxicity in some patients. The interindividual variability of this toxicity is largely due to genetic variations in target genes and enzymes of metabolism of this drug, such as thymidylate synthase and dihydropyrimidine dehydrogenase. The enzyme cytidine deaminase (CDA), involved in the activation of capecitabine, also has several variants associated with an increased risk of toxicity to treatment, although its role as a biomarker is not yet clearly defined.Therefore, our main objective is to study the association between the presence of genetic variants in CDA gen, CDA enzymatic activity and the development of severe toxicity in patients treated with capecitabine whose initial dose was adjusted based on the genetic profile of the dihydropyrimidine dehydrogenase gen (DPYD). Method: Prospective multicenter observational cohort study, focused on the analysis of the genotype-phenotype association of the CDA enzyme.After the experimental phase, an algorithm will be developed to determine the dose adjustment needed to reduce the risk of treatment toxicity according to CDA genotype, developing a clinical guide for capecitabine dosing according to genetic variants in DPYD and CDA. Based on this guide, a Bioinformatics Tool will be created to generate the pharmacotherapeutic report automatically, facilitating the implementation of pharmacogenetic advice in clinical practice. This tool will be a great support in making pharmacotherapeutic decisions based on the patient's genetic profile, incorporating precision medicine into clinical routine. Once the usefulness of this tool has been validated, it will be offered free of charge to facilitate the implementation of pharmacogenetics in hospital centers and equitably benefit all patients on capecitabine treatment. (AU)

El polimorfismo de un solo nucleótido rs1800795 en el gen IL6 no está asociado con el glaucoma primario de ángulo abierto en la población mexicana / The rs1800795 single nucleotide polymorphism in the IL6 gene is not associated with primary open angle glaucoma in Mexican population

Objetivo La interleucina 6 (IL-6) es una citoquina proinflamatoria con efectos pleiotrópicos que se ha relacionado con el glaucoma primario de ángulo abierto (GPAA) debido a su efecto particular de protección de las células ganglionares de la retina (CGR) contra la apoptosis. Se han asociado diferentes polimorfismos de un solo nucleótido (PSN) con el GPAA. El objetivo de este estudio fue determinar si existe una asociación entre el PSN de IL-6 rs1800795 (−174 G>C) y un mayor riesgo de padecer GPAA en la población mexicana occidental. Métodos Se incluyeron 165 pacientes mestizos mexicanos no emparentados con GPAA y 108 sujetos de control. Se extrajo el ADN genómico de los leucocitos y se purificó, seguido de la genotipificación y la amplificación por reacción en cadena de la polimerasa (PCR) con sondas TaqMan® Biosystem®. Se evaluó la diversidad alélica y genotípica entre los casos y los sujetos de control. Resultados No hubo asociación estadísticamente significativa entre las frecuencias alélicas y genotípicas, ni con modelos de asociación genética dominante ni recesiva (p>0,05). Conclusiones Aunque existe un papel de la IL6 en la fisiopatología del GPAA, nuestros resultados descartan la asociación entre la IL-6 y el PSN rs1800795 mostrando no ser un índice de mayor riesgo de GPAA en la población mexicana (AU)

Purpose Interleukin-6 (IL-6) is a proinflammatory cytokine with pleiotropic effects which has been related to primary open angle glaucoma (POAG) due to its particular effect of protecting the retinal ganglion cells (RGc) from the apoptosis. Different single nucleotide polymorphisms (SNP) have been associated with POAG. The aim of this study was to determine whether an association between IL-6 rs1800795 (−174 G>C) SNP and a higher risk for POAG is present in western Mexican population. Methods One hundred and sixty-five unrelated Mexican mestizo patients with POAG and 108 control subjects were included. Genomic DNA was extracted from leukocytes and purified, followed by genotyping and amplification by polymerase chain reaction (PCR) with Taqman Biosystem probes. Allelic and genotypic diversity was evaluated between cases and control subjects. Results There was no statistically significant association between allele and genotype frequencies, neither with dominant nor recessive genetic association models (P>.05). Conclusion Even though there is a role of IL6 in the pathophysiology of POAG, our results ruled out the association between IL-6 and the rs1800795 SNP showing not to be an index of higher risk for POAG in Mexican population (AU)

Genetic diversity and virulence characteristics of biofilm-producing uropathogenic Escherichia coli / Diversidad genética y características de virulencia de Escherichia coli uropatógena productora de biopelículas

Uropathogenic E. coli (UPEC) strains exhibit different levels of biofilm formation that help adhesion of the bacteria to uroepithelial cells. We investigated the genetic diversity and virulence-associated genes (VAGs) of biofilm-producing UPEC. A collection of 107 biofilm-producing (BFP) UPEC strains isolated from patients with UTI in Iran were divided into three groups of strong, moderate, and weak BFPs after a quantitative microtiter plate assay, and the involvement of curli and cellulose in adhesion of the strains to T24 cell line was confirmed by the construction of csgD and yedQ mutants of two representative UPEC strains. BFP strains were tested for their genetic diversity, phylogenetic groups, and the presence of 15 VAGs. A significant decrease in adhesion of csgD and yedQ mutant strains confirmed the role of biofilm production in adhesion to uroepithelial cells. A high diversity was found among all three groups of strong (Di = 0.998), moderate (Di = 0.998), and weak (Di = 0.988) BFPs with majority of the strains belonging to phylogroups B2 (44.9%) and A (24.3%). Strong BFP strains carried significantly higher level papEF, hlyA, and iutA than other BFP groups. In contrast, the presence of fimH, focG, sfaS, set-1, and cvaC was more pronounced among weak BFP strains. There exists a high genetic diversity among the BFP strains with different VGA profiles. However, the high prevalence of phylogroup A among BFP strains suggests the fitness of commensal E. coli strains to cause UTI in this country.(AU)

Variabilidad de la expresión clínica de la encefalopatía KCNB1 / Variability of the clinical expression of KCNB1 encephalopathy

Introducción: El gen KCNB1 codifica un canal de potasio dependiente del voltaje que regula corrientes transmembrana en las neuronas piramidales. Variantes en heterocigosis se han asociado recientemente con encefalopatías epilépticas de inicio precoz y discapacidad intelectual, pero su caracterización clínica no está completamente definida.Objetivo: Describir el espectro clínico asociado con variantes de KCNB1 en pacientes pediátricos. Pacientes y métodos: Estudio retrospectivo de cuatro pacientes procedentes de tres familias con encefalopatía KCNB1, analizando características clínicas y electroencefalográficas de la epilepsia, manifestaciones neurológicas asociadas y patrón de neurodesarrollo. Resultados: En dos, la mutación en KCNB1 fue de novo; las otras dos, hermanas, heredaron la variante de un progenitor con mosaicismo germinal. Todos presentaban discapacidad intelectual leve-moderada; dos pacientes, trastorno del espectro autista; y otros dos, trastorno por déficit de atención/hiperactividad. Sólo el caso 2 mostro´ alteraciones en la resonancia magnética cerebral: atrofia cortical evolutiva. Tres desarrollaron epilepsia (casos 1-3). Caso 1: inicio a los 9,5 meses con síndrome de West bien controlado con vigabatrina y zonisamida. Caso 2: inicio a los 13 meses con síndrome de West; desarrollo evolutivo de crisis polimorfas (atónicas, hipermotoras, disautonómicas y tónicas) refractarias a 10 fármacos antiepilépticos y corticoides. Asocio´ trastorno del movimiento caracterizado por ataxia, discinesias y temblor. Caso 3: inicio a los 14,5 años con crisis atónicas, patrón multifocal en el electroencefalograma y adecuado control con levetiracetam. Conclusiones: La encefalopatía KCNB1 presenta una evolución natural heterogénea, principalmente respecto a la epilepsia, y se observan desde pacientes con epilepsia refractaria hasta pacientes sin crisis epilépticas...(AU)

Introduction: The KCNB1 gene encodes a voltage-dependent potassium channel that regulates transmembrane currents in pyramidal neurons. Heterozygous variants have recently been associated with early-onset epileptic encephalopathies and intellectual disability, but their clinical characterisation has not yet been fully defined. Aim: To describe the clinical spectrum associated with variants of KCNB1 in paediatric patients. Patients and methods. Retrospective study of four patients from three families with KCNB1 encephalopathy, including an analysis of the clinical and electroencephalographic features of epilepsy, associated neurological manifestations and neurodevelopmental pattern. Results: In two of them, the mutation in KCNB1 was de novo; the other two, who were sisters, inherited the variant from a parent with germline mosaicism. All had mild-to-moderate intellectual disability, two patients had autistic spectrum disorder and two had attention deficit hyperactivity disorder. Only case 2 displayed alterations in the MRI brain scan: progressive cortical atrophy. Three of them developed epilepsy (cases 1-3). Case 1: onset at 9.5 months with West syndrome that was well controlled with vigabatrine and zonisamide. Case 2: onset at 13 months with West syndrome, evolutionary development of polymorphic seizures (atonic, hypermotor, dysautonomic and tonic) that were refractory to 10 antiepileptic drugs and corticosteroids. Accompanied by a movement disorder characterised by ataxia, dyskinesias and tremor. Case 3: onset at 14.5 years with atonic seizures, multifocal EEG pattern and adequate control with levetiracetam.Conclusions: KCNB1 encephalopathy has a heterogeneous natural history, mainly with respect to epilepsy, ranging from patients with refractory epilepsy to patients without any epileptic seizures. All had neurodevelopmental disorders, such as intellectual disability or autism spectrum disorder, independent of epilepsy.(AU)

Maximum genetic proportion of metric traits from different regions of the skull in ancient humanpopulations of Northwestern Argentina

In order to explain the evolutionary process of ancient human populations that inhabited a specific geographical region from quantitative skull traits, it is advisable to know the evolutionary potential of metric characters. For this reason, the proportion of the maximum genetic variance or maximum heritability (h2m) of the variables studied was estimated. In addition, it was evaluated whether h2m changes between regions of the skull (face, base and vault) and the degree of association between the phenotypic variance and the maximum genetic variance. Twenty-one symmetrical variables on the left and right sides of the skull were measured in 245 skulls from five prehistoric samples from northwestern Argentina. The upper limit of heritability was estimated using the repeated measurement method. To test whether there are differences between the h2m of each group, the Kruskal-Wallis test was used. The maximum genetic values of each variable were obtained through a regression analysis (right measure on left measure). The relationship between phenotypic and maxi-mum genetic values was evaluated by correlation analysis. Significant bilateral difference is demon-strated in six of 21 characters. The average h2m is 0.77 and ranges between 0.58 and 0.93. The aver-age correlation between phenotypic values and maximum genotypic values was 0.8 (R2=0.65), suggesting that it is possible to make inferences of the genetic structure of the population from phenotypic information. The high proportion of maximum observed genetic variance indicates an important evolutionary potential of the craniofacial complex in ancient populations of northwestern Argentina

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No se puede hablar de MELAS sin porcentaje de heteroplasmia ni investigación multisistémica / No MELAS syndrome without heteroplasmy levels or multisystem examination

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Genetic variation of the dopamine D2 receptor gene: association with the reinforcing value of food and eating in the absence of hunger in Chilean children / Variación genética del gen del receptor D2 de dopamina: asociación con el valor reforzador de la comida y el comer en ausencia de hambre en niños chilenos

BACKGROUND: food is a powerful reinforcer that motivates people to eat. The TaqI A1 polymorphism (rs1800497; T>C) downstream of the dopamine D2 receptor (DRD2) gene has been associated with diminished DRD2 receptor density, higher food reinforcement, and impaired eating behavior in adults. OBJECTIVE: to evaluate the association between the rs1800497 polymorphism and the reinforcing value of food and eating in the absence of hunger in Chilean children. MATERIAL AND METHOD: nineteen Chilean children (aged 8-12 years) who were carriers of the A1-allele and 19 age- and gender-matched non-carriers (A2-allele) were evaluated on the reinforcing value of food and eating in the absence of hunger. Anthropometric measures were performed by standard procedures. Briefly, children received a standard pre-load lunch followed by an ad-libitum exposure to palatable foods. RESULTS: no differences were found between A1-allele carriers and non-carriers, whether obese or non-obese, in ad libitum energy intake, macronutrient consumption, or the relative reinforcing value of food (p > 0.05). In obese children, A1 carriers reported significantly lower satiety and fullness before lunch (p < 0.05). However, in children with normal weight A1 carriers were found to exhibit trends for greater satiety and fullness before lunch when compared to non-carriers, but this trend reversed after lunch such that carriers exhibited lower satiety and fullness (p = 0.06). CONCLUSIONS: although TaqI A1 may play an important role in some eating behavior-related traits such as satiety and fullness, especially in obese children, our findings indicate that this polymorphism does not appear to affect eating in the absence of hunger or food reinforcement in children

ANTECEDENTES: los alimentos son un poderoso reforzador de la alimentación. El polimorfismo TaqI A1 (rs1800497; T> C) del gen del receptor 2 de dopamina (DRD2) se ha asociado con una menor densidad de DRD2, un mayor refuerzo alimentario y un comportamiento alimentario alterado en adultos. OBJETIVO: evaluar la asociación entre el polimorfismo rs1800497, el valor reforzador del alimento y la conducta de comer en ausencia de hambre en niños chilenos. MATERIAL Y MÉTODO: treinta y ocho niños chilenos, 19 portadores del alelo A1 y 19 no portadores (alelo A2), pareados por género y edad, fueron evaluados en condiciones de laboratorio para determinar el valor reforzador del alimento y la conducta de comer en ausencia de hambre. Las mediciones antropométricas se realizaron por procedimientos estándar. Brevemente, los niños recibieron un almuerzo estándar seguido de una exposición ad-libitum a alimentos sabrosos. RESULTADOS: no hubo diferencias en la ingesta ad libitum de energía, ni en el consumo de macronutrientes, ni en el valor reforzador del alimento entre los portadores del alelo A1 frente a los no portadores (p > 0,05). Entre los niños obesos, los portadores del alelo A1 reportaron un menor nivel de saciedad y plenitud pre-almuerzo (p < 0,05). Sin embargo, entre los niños con normopeso se observó que los portadores de A1 tenían tendencia a presentar un mayor grado de saciedad y plenitud (pre-almuerzo) frente a los no portadores. Esta tendencia se invirtió post-almuerzo, de modo que los portadores exhibieron menor saciedad y plenitud (p = 0,06). CONCLUSIONES: la variante TaqI A1 podría desempeñar un papel importante en algunos rasgos relacionados con la conducta alimentaria, como la saciedad y la plenitud

TSC2/PKD1 contiguous gene syndrome, with emphasis on a case with an atypical mild polycystic kidney phenotype and a novel genetic variant / Síndrome de genes contiguos TSC2/PKD1 con énfasis en un caso con un fenotipo atípico de riñón poliquístico leve y una nueva variante genética

About 80% of patients with tuberous sclerosis complex (TSC) present renal involvement, usually as angiomyolipomas followed by cystic disease. An early diagnosis of polycystic kidney disease (PKD) in such patients is frequently related to the TSC2/PKD1 contiguous gene syndrome (PKDTS). Molecular confirmation of PKDTS is important for a prompt diagnosis, which can be complicated by the phenotypic heterogeneity of PKD and the absence of a clear phenotype-genotype correlation. Herein, we report three PKDTS pediatric patients. The case 3 did not present a classic PKDTS phenotype, having only one observable cyst on renal ultrasound at age 4 and multiple small cysts on magnetic resonance imaging at age 15. In this patient, chromosomal microarray analysis showed a gross deletion of 230.8 kb that involved TSC2, PKD1 and 13 other protein-coding genes, plus a heterozygous duplication of a previously undescribed copy number variant of 242.9kb that involved six protein-coding genes, including SSTR5, in the 16p13.3 region. Given the observations that the case 3 presented the mildest renal phenotype, harbored three copies of SSTR5, and the reported inhibition of cystogenesis (specially in liver) observed with somatostatin analogs in some patients with autosomal dominant PKD, it can be hypothesized that other genetic factors as the gene dosage of SSTR5 may influence the PKD phenotype and the progression of the disease; however, future work is needed to examine this possibility

Un 80% de los pacientes con complejo de esclerosis tuberosa (CET) presentan afectación renal, generalmente angiomiolipomas, seguidos de enfermedad quística. Un diagnóstico temprano de la enfermedad renal poliquística (ERP) en estos pacientes se relaciona con frecuencia con el síndrome de genes contiguos TSC2/PKD1 (PKDTS). La confirmación molecular de PKDTS es importante para establecer un diagnóstico oportuno, que puede complicarse por la heterogeneidad fenotípica de PKD y la ausencia de una clara correlación entre fenotipo y genotipo. En este artículo presentamos los casos de 3 pacientes pediátricos con PKDTS. El caso 3 no presentó un fenotipo PKDTS clásico, con solo un quiste observable en la ecografía renal a los 4 años y numerosos quistes pequeños en la resonancia magnética a los 15 años. En este paciente, el análisis de microarreglos para análisis cromosómico global mostró una eliminación total de 230,8 kb que involucró a TSC2, PKD1 y otros 13 genes codificantes de proteínas, más una duplicación heterocigota para una variante de número de copias no descrita previamente de 242,9 kb que involucró a 6 genes codificantes de proteínas, entre ellos SSTR5, en la región 16p13.3. Dado que el caso 3 mostraba el fenotipo renal menos severo, contaba con tres copias del gen SSTR5 y a que se ha observado una inhibición en la cistogénesis (especialmente en el hígado) con los análogos de somatostatina en algunos pacientes con ERP autosómica dominante, podemos hipotetizar que existen otros factores genéticos como la dosis génica de SSTR5 que pudieran influir en el fenotipo y la progresión de la ERP; sin embargo, se necesitan estudios adicionales para investigar esta posibilidad

Influencia de la variante rs670 del gen APOA1 en la respuesta HDL sérica a una dieta hipocalórica enriquecida con grasas poliinsaturadas frente a una enriquecida con grasas monoinsaturadas / Influence of rs670 variant of APOA1 gene on serum HDL response to an enriched-polyunsaturated vs. an enriched-monounsaturated fat hypocaloric diet

Antecedentes y objetivos: las variantes genéticas del gen APOA1 se han relacionado con el perfil lipídico en sujetos obesos. Nuestro objetivo fue analizar los efectos del polimorfismo del gen rs670 APOA1 sobre el estado metabólico tras la ingesta de dos dietas hipocalóricas enriquecidas con grasas poliinsaturadas o con grasas monoinsaturadas. Métodos: trescientos sesenta sujetos obesos se asignaron al azar a dos grupos de intervención. Un grupo recibió una dieta enriquecida en grasas poliinsaturadas (dieta P) y el otro grupo una dieta enriquecida en grasas monoinsaturadas (dieta M) durante 12 semanas. Se evaluaron los efectos sobre los biomarcadores relacionados con el metabolismo lipídico y de hidratos de carbono antes y después de la intervención. Resultados: el índice de masa corporal, el peso, la masa grasa, la circunferencia de la cintura, la presión arterial sistólica, las concentraciones plasmáticas de leptina y la circunferencia de la cintura disminuyeron en todos los pacientes tras ambas dietas. En los portadores del alelo A, después de 12 semanas con la dieta P, los niveles de insulina (delta: -7,3 ± 2,2 UI/I; p = 0,01) y HOMA-IR (delta: -2,8 ± 0,5 unidades; p = 0,02) mejoraron de manera significativa. Tras el tratamiento con la dieta M, los niveles plasmáticos de insulina (delta: -5,9 ± 1,2 UI/I; p = 0,01) y HOMAIR (delta: -2,1 ± 0,8 unidades; p = 0,02) también mejoraron en los portadores del alelo A. Después de la intervención dietética con la dieta P, el colesterol-LDL (delta: -12,1 ± 4,3 UI/I; p = 0,01) y el colesterol-HDL (delta: 2,6 ± 0,7 unidades; p = 0,01) disminuyeron significativamente en los portadores del alelo A. Conclusiones: nuestro estudio mostró la asociación del polimorfismo rs670 ApoA1 con los cambios de resistencia a la insulina inducidos por ambas dietas y aportó evidencia adicional sobre la mejoría del colesterol-HDL y el colesterol-LDL después de una dieta rica en grasas poliinsaturadas en los portadores del alelo A

Background and objectives: genetic variants of the APOA1 gene have been related to lipid profile in obese subjects. Our aim was to analyze the effects of the rs670 APOA1 gene polymorphism on metabolic changes secondary to an enriched-polyunsaturated fat vs. an enriched-monounsaturated fat hypocaloric diet. Methods: 360 Caucasian obese subjects were randomly allocated to two groups. One group received an enriched-polyunsaturated fat (diet P) and the other an enriched-monounsaturated fat hypocaloric diet (diet M) during 12 weeks. The effects on serum biomarkers related to lipid and carbohydrate metabolism were evaluated before and after the dietary intervention. Results: after both diets, body mass index, weight, fat mass, waist circumference, systolic blood pressure, plasma leptin concentration, and waist circumference decreased in all patients. After 12 weeks of intervention with diet P, plasma insulin levels and HOMA-IR decreased in A-allele carriers: delta: -7.3 ± 2.2 IU/L (p = 0.01), and delta: -2.8 ± 0.5 units (p = 0.02), respectively. The same changes in delta were observed after diet M in A-allele carriers: insulin delta: -5.9 ± 1.2 IU/L (p = 0.01), and HOMA-IR delta: -2.1 ± 0.8 units (p = 0.02). In A-allele carriers, LDL-cholesterol decreased and HDL-cholesterol increased after the dietary intervention with diet P: delta: -12.1 ± 4.3 mg/dL (p = 0.01), and delta: 2.6 ± 0.7 mg/dL (p = 0.01), respectively. No differences in lipid profile were observed after diet M. These improvements were not observed in non-A-allele carriers after both interventions. Conclusions: our study showed the association of the rs670 ApoA1 polymorphism with insulin resistance changes as induced by both diets. An enriched-polyunsaturated fat diet produced an additional improvement of HDL-cholesterol and LDL-cholesterol in A-allele carriers

Molecular screening and genetic diversity analysis of anticancer Azurin-encoding and Azurin-like genes in human gut microbiome deduced through cultivation-dependent and cultivation-independent studies

Azurin, a bacteriocin produced by a human gut bacterium Pseudomonas aeruginosa, can reveal selectively cytotoxic and induce apoptosis in cancer cells. After overcoming two phase I trials, a functional region of Azurin called p28 has been approved as a drug for the treatment of brain tumor glioma by FDA. The present study aims to improve a screening procedure and assess genetic diversity of Azurin genes in P. aeruginosa and Azurin-like genes in the gut microbiome of a specific population in Vietnam and global populations. Firstly, both cultivation-dependent and cultivation-independent techniques based on genomic and metagenomic DNAs extracted from fecal samples of the healthy specific population were performed and optimized to detect Azurin genes. Secondly, the Azurin gene sequences were analyzed and compared with global populations by using bioinformatics tools. Finally, the screening procedure improved from the first step was applied for screening Azurin-like genes, followed by the protein synthesis and NCI in vitro screening for anticancer activity. As a result, this study has successfully optimized the annealing temperatures to amplify DNAs for screening Azurin genes and applying to Azurin-like genes from human gut microbiota. The novelty of this study is the first of its kind to classify Azurin genes into five different genotypes at a global scale and confirm the potential anticancer activity of three Azurin-like synthetic proteins (Cnazu1, Dlazu11, and Ruazu12). The results contribute to the procedure development applied for screening anticancer proteins from human microbiome and a comprehensive understanding of their therapeutic response at a genetic level

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Pulsed-field gel electrophoresis fingerprinting of Campylobacter jejuni and Campylobacter coli strains isolated from clinical specimens, Iran

The aim of this study was to determine the clonal correlation of Campylobacter strains isolated from diarrheal children under 5 years of age in Iran using the PFGE method and to determine the antimicrobial susceptibility and virulence gene content of strains. Of 750 patients with bacterial diarrhea, 33 (4%) Campylobacter spp., including 31 C. jejuni (94%) and 2 C. coli (6%), were isolated during 18-month period in Tehran, Iran. Except for one strain, remaining Campylobacter strains were positive for the flaA gene. A complete set of cytolethal distending toxin (CDT) encoding genes (cdtABC) were detected in 52% of the C. jejuni strains, while the 2 C. coli isolates under study only harbored cdtA and cdtB of the CDT cluster. All strains were resistant to at least three antibiotic classes. Resistance to ampicillin among C. coli and C. jejuni strains was 100% and 84%, respectively, and 80% of all strains were susceptible to gentamicin. PFGE genotyping generated 19 pulsotypes with two major clusters, displaying the maximum and minimum similarity of 100% and 26%, respectively. The C. coli strains showed clearly distinct pulsotypes and each fell within separate clusters. A very homogeneous Campylobacter population was detected among Iranian patients with 33 % of strains showing identical banding patterns and no clear correlation was observed between antibiotic resistance profiles and PFGE patterns of the isolates

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Predicción de riesgo de cáncer de mama en mujeres sanas de población española basado en el estudio de variantes genéticas / Prediction of cancer risk based on study of genetic variants in healthy women in the Spanish population

Objetivo: Estratificación de la población general con base en las variantes genotípicas para seleccionar a aquellas mujeres de alto riesgo a desarrollar un cáncer de mama que puedan ser candidatas a un seguimiento individualizado. Material y métodos: Se ha realizado un estudio caso-control en 856 mujeres con cáncer de mama y 839 mujeres controles de la población general pareadas por edad, analizando la asociación entre el riesgo a desarrollar cáncer de mama y un grupo de variantes basado en 76 polimorfismos de un cambio de base (SNP) de susceptibilidad. Resultados: Se han establecido 2curvas de casos y controles con base en las odds ratio (OR) genotípicas que diferencian las 2poblaciones con significación estadística (p = 2,293×10-15). Asimismo, se ha estratificado la población de casos y controles e identificado un 14% de la población que se encontraría en el grupo de alto riesgo con una OR > 2 (> 25% probabilidades de desarrollar un cáncer de mama). Este grupo sería candidato a un seguimiento individualizado. Conclusiones: El Polygenic Risk Score es un predictor del riesgo del cáncer de mama independiente que puede ayudar a seleccionar mujeres con alto riesgo para establecer medidas de seguimiento y tratamiento individualizado en función del riesgo genético

Objective: To stratify the general population based on genotypic variants in order to select women at high risk of breast cancer who could be candidates for individualized follow-up. Material and methods: We performed a case-control study in 856 women with breast cancer and 839 aged-matched control women from the general population. We analysed the association between the risk of developing breast cancer and a group of variants based on 76 susceptibility single nucleotide polymorphisms. Results: Two case-control curves were established based on genotypic odds ratios (OR) that differentiated the 2populations with statistical significance (P=2.293×10-15). Stratification of the case-control population showed that 14% of the population would be at high risk, with an OR>2 (> 25% probability of developing breast cancer). Persons in this group would be candidates for individualized follow-up. Conclusions: The Polygenic Risk Score is an independent predictor of breast cancer risk that may help to select women at high risk, with a view to establishing individualised follow-up and treatment according to genetic risk

Associations between experimental substance use, faah-gene variations, impulsivity and sensation seeking / Asociaciones entre el uso experimental de sustancias, variaciones del gen FAAH, impulsividad y búsqueda de sensaciones

Background: Experimental substance use among young people is related to individual factors including personality traits such as impulsivity and sensation seeking, and genetic variations such as single nucleotide polymorphisms (SNPs) in the fatty acid amide hydrolase (FAAH) gene. The objective of this study is to analyze the relationship between these three sets of variables. Methods: Volunteer undergraduate students (N = 861, 76% female, M = 20.7 years) completed an ad hoc questionnaire on variables related to their consumption of alcohol, tobacco, cannabis, synthetic drugs and cocaine. In addition, 591 of them completed the Barratt Impulsiveness Scale-11 (BIS-11) and the Sensation Seeking Scale-V (SSS-V). All participants were genotyped in FAAH C385A SNP and its proxy variant rs12075550. Results: Consistent with previous data, both impulsivity and sensation seeking were associated with most of the variables related to experimental substance use. In addition, we found the first evidence of an association between the rs12075550 SNP and some of these consumption phenotypes. However, no significant association was found between either of the two SNPs and impulsivity or sensation seeking. Conclusions: The results highlight the importance of considering both personality and genetic differences, together with contextual factors, in the analysis of substance use

Antecedentes: el uso experimental de sustancias en los jóvenes está relacionada con factores individuales que incluyen rasgos de personalidad, como impulsividad o búsqueda de sensaciones, y variaciones genéticas, como polimorfismos de un solo nucleótido (SNPs) del gen amida hidrolasa de ácidos grasos (FAAH). El objetivo de este estudio es analizar la relación entre estos tres conjuntos de variables. Método: estudiantes universitarios voluntarios (N = 861, 76% mujeres, M = 20,7 años) rellenaron un cuestionario ad hoc de variables relacionadas con el consumo de alcohol, tabaco, cannabis, drogas sintéticas y cocaína. Además, 591 de ellos rellenaron las escalas BIS-11 y SSS-V. Se genotipó a todos ellos en SNP FAAH C385A y su variante proxy rs12075550. Resultados: como se esperaba, la impulsividad y la búsqueda de sensaciones estuvieron asociadas con la mayor parte de las variables relativas al uso experimental de sustancias. Además, encontramos por primera vez evidencia de una asociación entre rs12075550 y algunos de estos fenotipos de consumo. Sin embargo, no encontramos asociaciones significativas entre SNPs e impulsividad o búsqueda de sensaciones. Conclusiones: los resultados resaltan la importancia de tener en cuenta las diferencias genéticas y las de personalidad, junto con los factores contextuales, al analizar el uso de sustancias

German Ethics Council's Opinion: intervening in the human germline

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Variabilidad genética de Klebsiella pneumoniae con carbapenemasa tipo KPC proveniente de diferentes estados de Venezuela / Genetic variability of carbapenemase KPC-producing Klebsiella pneumoniae isolated at different states in Venezuela

Introducción: En Venezuela hay reportes de Klebsiella pneumoniae con carbapenemasa tipo KPC. Sin embargo, desde su primer reporte en el 2008, son muy escasos los estudios de epidemiología molecular que se han realizado en estos aislados. Métodos: Los objetivos de esta investigación fueron detectar la producción de betalactamasas de espectro extendido (BLEE) (blaTEM y grupo blaCTX-M-1) y determinar la relación genética de 30 aislados pertenecientes a brotes importantes de K. pneumoniae productores de carbapenemasa tipo KPC derivados por once centros sanitarios de diferentes estados de Venezuela entre enero de 2008 y diciembre de 2012 mediante electroforesis en campo pulsante (ECP). Resultados: Todos los aislados fueron identificados como K. pneumoniae subsp. pneumoniae. Los aislados mostraron el mayor porcentaje de resistencia al ertapenem, un 97%. En todos los aislados se detectó el gen tipo KPC. El 73% presentó BLEE (en el 68% se detectó blaTEM y en el 27% blaTEM, CTX-M-1). En la ECP se detectaron 11 agrupaciones. Conclusión: Durante los años 2008-2012 se demostró que existe una gran diversidad genética en los aislados en estudio. Se determinó que algunos aislados circularon en los 11 centros sanitarios. Los resultados de esta investigación plantean la necesidad de fortalecer la vigilancia epidemiológica y el desarrollo de actividades para prevenir y controlar este tipo de microorganismo

Introduction: In Venezuela, there have been some reports of carbapenemase KPC-producing Klebsiella pneumoniae. Nevertheless, since the first report in 2008, only a few studies have been done on their molecular epidemiology in this country. Methods: The aims of this study were to detect extended-spectrum betalactamase (ESBL)-producing (blaTEM and blaCTM-M-1) and to determine the genetic relationship between 30 isolates of carbapenemase KPC-producing K. pneumoniae taken from patients at eleven health centers in different states of Venezuela from January 2008 to December 2012, using pulsed-field gel electrophoresis (PFGE). Results: All isolates were identified as K. pneumoniae subsp. pneumoniae. Isolates showed the highest resistance to the ertapenem, 97%. The KPC gene was detected in all studied strains. Seventy three percent showed ESBL, having the blaTEM in 68% and blaTEM, CTX-M-1 in 27% of the strains. Eleven groups were found using the field-pulsed gel electrophoresis. Conclusion: High genetic diversity was found during 2008-2012 in K. pneumoniae isolated at different states in Venezuela, some of them circulating at eleven health centers. Results showed the importance of performing epidemiologic studies and the need to develop some activities to control this type of microorganisms