Genética y genómica de la longevidad y el envejecimiento / Genetics and genomics of longevity and aging

El envejecimiento y la longevidad son procesos que involucran una serie de factores genéticos, bioquímicos y ambientales. En esta revisión se tratan algunas cuestiones sobre estos dos procesos biológicos y epigenéticos. Se presentan los genes más importantes en estos procesos, así como se ejemplifican enfermedades que presentan un aceleramiento o falla en la longevidad y el envejecimiento. Se usa el análisis inteligente de datos para hallar interacciones de proteínas/genes que expliquen estos dos fenómenos biológicos.

Aging and longevity are processes that involve a series of genetic, biochemical and environmental factors. This review addresses some issues about these two biological and epigenetic processes. The most important genes in these processes are presented, as well as diseases that present an acceleration or failure in longevity and aging. Intelligent data analysis is used to find protein/gene interactions that explain these two biological phenomena.

Estrogen deficiency influences TNF-α and IL-1ß gene expression in the odontogenic region of dental hypofunctional condition / A deficiência de estrógeno influencia a expressão gênica de TNF-α e IL-1ß na região odontogênica de dentes em hipofunção

Objetivo: Evidências científicas sugerem que a deficiência de estrógeno e fatores genéticos influenciam o desenvolvimento do sistema estomatognático. Este estudo teve como objetivo avaliar a influência da deficiência de estrógeno na expressão gênica de TNF-α, IL-1ß, IL-6 e IL-10 durante o desenvolvimento dentário em modelo murino. Material e Métodos: Ratas Wistar Hannover foram divididas em dois grupos de acordo com a intervenção recebida: Grupo Hipoestrogenismo - cirurgia de ovariectomia e Grupo Controle - cirurgia fictícia. Para avaliar o desenvolvimento dentário, o incisivo inferior foi escolhido. O modelo de hipofunção dos incisivos inferiores foi realizado por ajuste incisal. O incisivo homólogo exercia hiperfunção dentária. Os animais foram avaliados durante todo o período puberal. Após a eutanásia, as hemimandíbulas foram removidas para avaliar a expressão gênica do TNF-α, IL-1ß, IL-6 e IL-10 na região odontogênica dos incisivos por meio de PCR em tempo real. Foi realizado o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância foi de 5%. Resultados: Houve diferenças estatisticamente significativas na expressão gênica de TNF-α e IL-1ß entre os grupos hipoestrogenismo e controle sob condição de hipofunção dentária (p=0,0084, p=0,0072, respectivamente). Conclusão: A deficiência de estrógeno influencia a expressão gênica de TNF-α e IL-1ß na região odontogênica de dentes hipofuncionais (AU)

Objective: Scientific evidence suggests that estrogen deficiency and genetic factors have an influence on the development of the stomatognathic system. This study aimed to evaluate the influence of estrogen deficiency on the gene expression of TNF-α, IL-1ß, IL-6 and IL-10 during dental development in a murine model. Material and Methods: Wistar Hannover rats were divided into two groups according to the intervention received: Hypoestrogenism Group - ovariectomy surgery and Control Group - fictitious surgery. To evaluate the dental development, the lower incisor was chosen. The mandibular incisor hypofunction model was performed by incisal adjustment. The homologous incisor exerted a hyperfunction. The animals were evaluated throughout the pubertal period. After euthanasia, the hemimandibles were removed to evaluate the gene expression of the TNF-α, IL-1ß, IL-6 and IL-10 in the odontogenic region of the incisors through real time PCR. Kruskal-Wallis test and Dunn's posttest were performed. The level of significance was 5%. Results: There were statistically significant differences of TNF-α and IL-1ß gene expression between the hypoestrogenism and control groups under hypofunction condition (p=0.0084, p=0.0072, respectively). Conclusion: Estrogen deficiency influences TNF-α and IL-1ß gene expression in the odontogenic region of the hypofunctional teeth. (AU)

The Human Host Defense Peptide LL-37 Overexpressed in Lung Cell Lines by Methanolic Extract of Valeriana officinalis

Abstract The present study investigated the effects of valerian methanolic extract and valerenic acid on the expression of LL-37 gene and protein in A549 and MRC5 line cells. After preparing Valerian seeds, sowing them in March 2020, and harvesting the rhizome in October 2020, the extract was prepared from the valerian rhizome by maceration method. Valerian acid content was determined using high performance liquid chromatography (HPLC). Two cell lines (A549 and MRC-5) were used to study the effects of valerian extract, and the MTT test was used to evaluate cell viability. The expression of LL-37 mRNA and protein was assessed by Real-Time PCR and western blot, respectively. In vivo safety assessments and histopathological analysis were also conducted. Data was analyzed by Graphpad Prism 8 software. Valerian methanolic extract and valerenic acid upregulated the LL-37 mRNA and protein expression in both treated cell lines. Valerenic acid showed a greater effect on upregulating LL-37 expression than valerian methanolic extract. A549 cells were more sensitive to valerian methanolic extract compared to MRC5 cells, and its cell viability was reduced. Furthermore, liver and kidney-related safety assessments showed that valerian methanolic extract had no toxic effects. In general, it was concluded that the methanolic extract of valerian as well as the resulting valerenic acid as the most important component of the extract has the ability to upregulate LL-37expression. Therefore, methanolic extract of valerian and valerenic acid can be considered for improving the immune system.

Artemisinin drug resistance and monitoring: a narrative review

Artemisinin drug resistance is one of the major reasons for malaria treatment failures in the sub-Saharan African countries where artemisinin-based combination therapy (ACT) is the first-line treatment for uncomplicated malaria. The occurrence of single nucleotide polymorphisms (SNPs) is found to correlate with antimalarial drug resistance. With artemisinin, the SNPs occurs at the Kelch 13-propeller gene locus on chromosome 13. The artemisinin drug resistance surveillance strategy involves continuous monitoring of Kelch 13-propeller biomarker to detect emergence of mutations which could herald drug resistance in the region. In this narrative review paper, we examined existing literature to bridge the knowledge gap and accentuate the importance of routine surveillance for artemisinin resistance in sub-Saharan Africa. We conducted our search on PubMed database and Google Scholar to identify peer-reviewed articles, reports, and abstracts on artemisinin drug resistance using the following keywords; 'artemisinin drug resistance', 'antimalarial drug resistance', 'artemisinin-based combination therapy', 'Kelch 13-propeller', 'K13- propeller gene', and 'K13 molecular marker'. The review provided pertinent information on artemisinin derivatives, artemisinin-based combination therapy, molecular action of artemisinin, definition of artemisinin resistance, genetic basis of artemisinin drug resistance and discovery of Kelch 13, and the importance of artemisinin resistance surveillance. Molecular surveillance can provide healthcare policy makers a forecast of impending threats to malaria treatment. This is more so when drugs are in combination therapy, for instance, molecular surveillance can give a hint that one drug is failing despite the fact that in combination, it is still apparently clinically effective.

Analysis of SOD1 and C9orf72 mutations in patients with amyotrophic lateral sclerosis in Antioquia, Colombia / Análisis de mutaciones en los genes SOD1 y C9orf72 en pacientes con esclerosis lateral amiotrófica, Antioquia, Colombia

Introduction: Amyotrophic lateral sclerosis is a neurodegenerative disease with a possible multifactorial origin characterized by the progressive degeneration of motor neurons. There is a relatively high prevalence of this disease in Antioquia; however, there is no published genetic study to date in Colombia. Despite its unknown etiopathogenesis, more genetic risk factors possibly involved in the development of this disease are constantly found. Objetives: To evaluate G93A and D90A mutations in SOD1 gene and a short tandem repeat in C9orf72 within a cohort of amyotrophic lateral sclerosis patients from Antioquia, Colombia. Materials y methods: Thirty-four patients previously diagnosed with amyotrophic lateral sclerosis were included in the study. Peripheral blood samples were used for DNA extraction and genotyping. Results: No mutations were found in SOD1 (G93A and D90A) in any of the patients, while C9orf72 exhibited an allele with a statistically significant high prevalence in the study sample (8 hexanucleotide repeats of CAGCAG). Conclusions: These results suggest an association between this short tandem repeat (STR) in C9orf72 and the presence of amyotrophic lateral sclerosis in the studied population. However, this association should be established in a larger sample size and with controls from the same population. In addition, there also seems to be a genetic anticipation effect for the disease regarding this locus, since patients with this genotype present an earlier onset.

Introducción. La esclerosis lateral amiotrófica es una enfermedad neurodegenerativa con un posible origen multifactorial, caracterizado por una degeneración progresiva de las neuronas motoras. Hay una gran prevalencia relativa de esta enfermedad en Antioquia; sin embargo, no hay publicaciones de estudios genéticos en Colombia. A pesar de su etiopatogénesis desconocida, hay varios factores de riesgo genético que se encuentran constantemente en el desarrollo de esta enfermedad. Objetivo. Evaluar las mutaciones G93A y D90A del gen SOD1 y una repetición corta en tándem (Short Tandem Repeat, STR) en el locus C9orf72, en una cohorte de pacientes con esclerosis lateral amiotrófica en Antioquia, Colombia. Materiales y métodos. Se incluyeron 34 pacientes previamente diagnosticados en el estudio. Una muestra de sangre periférica se usó para extraer el ADN y, posteriormente, genotipificarlo. Resultados. No se encontraron mutaciones en el gen SOD1 (G93A y D90A), mientras que el C9orf72 exhibe un alelo con una significativa prevalencia en los pacientes del estudio (8 repeticiones del hexanucleótido G4C2). Conclusiones. Se sugiere una asociación entre la repetición en tándem en C9orf72 y la presencia de la esclerosis lateral amiotrófica en la población estudiada. Sin embargo, se sugiere hacer estudios adicionales e incluir un grupo control de la misma población. Además, se detecta un fenómeno de anticipación genética de la enfermedad, dado que los pacientes con el alelo de 8 repeticiones en C9orf72 presentan una edad temprana de aparición de los síntomas.

Etiopathogenesis of drug dependence: an explanatory synthesis from an epigenetic perspective / Etiopatogenia de las drogodependencias: una síntesis explicativa desde una perspectiva epigenética / Etiopatogenia das toxicodependências: uma síntese explicativa a partir de uma perspectiva epigenética

The use of substances with addictive potential is a relevant health problem. Scientific evidence suggests that the underlying mechanisms that regulate behavioral processes in addictions involve a complex interplay between genetic and environmental factors. Therefore, this narrative review aims to provide a framework to synthesize the evidence on gene-environment-agent interactions from the perspective of the natural history of the disease and the stages of the addictive process for alcohol, nicotine, cannabis, psychostimulants, and opioids. In this review, we conducted an exhaustive literature search without time limits in PubMed, Ebsco, Lilacs, and SciELO, reviewing the title and abstract we selected original articles in humans or animals that addressed the etiology of addictions according to the methodological approach of gene-environment (G-E) interaction, including articles in Spanish, English, and Portuguese. Genetic studies have revealed the critical role of epigenetic modifiers (histone acetylation) in maintaining brain homeostasis in pathological conditions and focusing on G-E interactions will also allow characterizing subgroups (based on environmental factors) at high risk for addictive behaviors that can be targeted for specific interventions, Thus, treatment strategies should encompass a combination of psychosocial interventions with gene therapy involving pharmacological manipulations of histones that may contribute to design better therapies and perhaps lead to more successful management of drug dependencies.

El consumo de sustancias con potencial adictivo es un problema relevante de salud. La evidencia científica sugiere que los mecanismos subyacentes que regulan los procesos comportamentales en las adicciones involucran un complejo interjuego entre factores genéticos y ambientales. Por lo tanto, esta revisión narrativa tiene como objetivo aportar un marco de referencia que permita sintetizar la evidencia sobre interacciones genes- ambiente-agente desde la perspectiva de la historia natural de la enfermedad y los estadios del proceso adictivo para: alcohol, nicotina, cannabis, psicoestimulantes y opioides. En esta revisión realizamos una búsqueda exhaustiva de la literatura sin límites de tiempo en PubMed, Ebsco, Lilacs y SciELO, revisando el título y el resumen se seleccionaron artículos originales en humanos o animales que abordaran la etiología de las adiciones según el enfoque metodológico de interacción entre genes y ambiente (G-A), incluyendo artículos en español, inglés y portugués. Los estudios genéticos han revelado el papel crítico de los modificadores epigenéticos (acetilación de las histonas) en mantener la homeóstasis cerebral en condiciones patológicas y enfocarse en las interacciones G-A también permitirá caracterizar subgrupos (basados en los factoresambientales) de alto riesgo para conductas adictivas que pueden ser objeto de intervenciones específicas, por lo que, las estrategias de tratamiento deben englobar una combinación de intervenciones psicosociales con terapia génica que involucren las manipulaciones farmacológicas de las histonas que pueden contribuir a diseñar mejores terapias y tal vez conducir a un manejo más exitoso de las drogodependencias.

O consumo de substâncias com potencial viciante é um relevante problema de saúde. Evidências científicas sugerem que os mecanismos subjacentes que regulam os processos comportamentais em vícios envolvem uma interação complexa entre fatores genéticos e ambientais. Portanto, esta revisão narrativa visa fornecer um quadro de referência que permita sintetizar as evidências sobre interações gene-ambiente-agente sob a perspectiva da história natural da doença e as etapas do processo de dependência para: álcool, nicotina, cannabis, psicoestimulantes e opióides. Nesta revisão, realizamos uma busca exaustiva da literatura sem limites de tempo no PubMed, Ebsco , Lilacs e SciELO, revisando o título e o resumo, foram selecionados artigos originais em humanos ou animais que abordassem a etiologia dos acréscimos de acordo com a abordagem metodológica de interação entre genes e ambiente (GA), incluindo artigos em espanhol, inglês e português. Estudos genéticos revelaram o papel crítico dos modificadores epigenéticos (acetilação de histonas) na manutenção da homeostase cerebral em condições patológicas, e o direcionamento das interações GA também permitirá caracterizar subgrupos (com base em fatores ambientais) de alto risco para comportamentos aditivos que podem ser alvo de ataques específicos. intervenções, portanto, as estratégias de tratamento devem abranger uma combinação de intervenções psicossociais com terapia gênica envolvendo manipulações farmacológicas de histonas que podem contribuir para projetar melhores terapias e talvez levar a um manejo mais bem-sucedido das dependências de drogas.

Obesidade genética não sindrômica: histórico, fisiopatologia e principais genes / Non-syndromic genetic obesity: history, pathophysiology and key genes

A obesidade é definida pelo excesso de gordura corporal acumulada no tecido adiposo quando o indivíduo atinge valores de IMC igual ou superior a 30 Kg/m2. Constitui um dos principais fatores de risco para várias doenças não transmissíveis (DNTs) como por exemplo, diabetes mellitus tipo 2 (DM2), doenças cardiovasculares, hipertensão arterial, acidente vascular cerebral e até mesmo o câncer. Embora a obesidade esteja diretamente relacionada com o consumo calórico excessivo em relação ao gasto energético diário, sua etiologia pode estar associada aos baixos níveis de atividade física, às alterações neuroendócrinas e aos fatores genéticos. Considerando o componente genético, esta pode ser classificada como sindrômicas e estar associada às alterações cromossômicas estruturais ou numéricas, ou como não sindrômica, quando relacionada, principalmente, com os polimorfismos de nucleotídeos simples (SNPs) em alelos que atuam como herança monogênica, ou ainda com a interação vários genes (poligênica multifatorial). Apesar de existirem muitas etiologias diferentes, normalmente a obesidade é tratada a partir da mesma abordagem, desconsiderando a fisiologia que a desencadeou. Dessa forma, o objetivo do presente trabalho foi abordar a obesidade genética não sindrômica por meio a) da descrição breve de perspectiva histórica sobre seu entendimento; b) da exposição dos principais mecanismos moleculares envolvidos com o controle de peso; c) da compilação dos principais genes e SNPs relacionados; d) da definição dos principais genes; e e) da abordagem das principais perspectivas de intervenção.

Obesity is defined as excess body fat accumulated in the adipose tissue when the individual reaches BMI values equal to or greater than 30 kg/m2. It is one of the main risk factors for several non-communicable diseases (NCDs), such as Type 2 Diabetes mellitus (T2D), cardiovascular diseases, high blood pressure, stroke and even cancer. Although obesity is directly related to excessive calorie intake in relation to daily energy expenditure, its etiology may be associated with low levels of physical activity, neuroendocrine changes, and genetic factors. Considering the genetic component, it can be classified as syndromic and be associated with chromosomal or numerical changes, or as non-syndromic and being related mainly to single nucleotide polymorphisms (SNPs) in alleles that act as monogenic inheritance, or with an interaction of several genes (multifactorial polygenic). Although there are many different etiologies, obesity is usually treated using the same approach, disregarding the physiology that triggered it. Thus, the aim of this study was to address non-syndromic genetic obesity through a) a brief description of a historical perspective on its understanding; b) the exposure of the main molecular mechanisms involved in weight control, c) the compilation of the key genes and related SNPs, d) the definition of the key genes and e) the approach of the main intervention representations.

Caracterización genotípica y biofilms de E. coli shigatoxigénica aisladas de casos clínicos humanos / Genotypic characterization and biofilms of shigatoxigenic E. coli isolated from human clinical cases

Resumen Escherichia coli shigatoxigénica (STEC) está involucrada en el desarrollo del síndrome urémico hemolítico, entre otras enfermedades que son de gran importancia para la salud pública e inocuidad alimentaria a nivel mundial. La capacidad de STEC de formar biofilms en los alimentos y en diferentes superficies podría conducir a la contaminación cruzada por el desprendimiento de las células bacterianas. El objetivo del presente trabajo fue detectar la presencia de genes que codifican factores de adherencia mediante la técnica de PCR y determinar la capacidad de formación de biofilms por medio de cultivo en microplacas de poliestireno de 96 pocillos y la técnica de cristal violeta, en cepas de STEC aisladas de muestras clínicas humanas en la ciudad de Mar del Plata, Argentina. El perfil de genes de adherencia más frecuente fue efa1, iha, fimCD, ehaA, lpfA1-3, lpfA2-2, cah (43,9%). Todas las cepas de STEC formaron biofilms con valores de densidad óptica entre 0,209 y 3,251 y el 54,4% (31/57) de las mismas fueron clasificadas como fuertes formadoras de biofilms. La capacidad de formación de biofilms de STEC constituye un riesgo evidente en la transmisión de este patógeno al ser humano a tener en cuenta para su vigilancia y control.

Abstract Shigatoxigenic Escherichia coli (STEC) is involved in the development of hemolytic uremic syndrome, among other diseases that are relevant to public health and food safety worldwide. The ability of STEC to form biofilms in food and on different surfaces could lead to cross-contamination by shedding bacterial cells. The aim of this work was to detect the presence of genes encoding adherence factors by the PCR technique and to determine the biofilm formation ability by culture in 96-well polystyrene microplates and the crystal violet technique, in STEC strains isolated from human clinical samples in Mar del Plata city, Argentina. The most frequent adherence gene profile was efa1, iha, fimCD, ehaA, lpfA1-3, lpfA2-2, cah (43.9%). All STEC strains formed biofilms with optical density values between 0.209 and 3.251. Also, the 54.4% (31/57) of STEC strains were classified as strong biofilm formers. The ability of STEC to form biofilms constitutes an evident risk in the transmission of this pathogen to humans, which must be taken into account for its surveillance and control.

Resumo A Escherichia coli shigatoxigênica (STEC) está envolvida no desenvolvimento da síndrome hemolítica urêmica, entre outras doenças relevantes para a saúde pública e segurança alimentar em todo o mundo. A capacidade do STEC de formar biofilmes nos alimentos e em diferentes superfícies poderia levar à contaminação cruzada através do desprendimento de células bacterianas. O objetivo do presente trabalho foi detectar a presença de genes que codificam fatores de aderência através da técnica PCR e determinar a capacidade de formação de biofilme por cultura em microplacas de poliestireno de 96 poços e da técnica de cristal violeta, em cepas STEC isoladas de amostras clínicas humanas na cidade de Mar del Plata, Argentina. O perfil de genes de aderência mais frequente foi efa1, iha, fimCD, ehaA, lpfA1-3, lpfA2-2, cah (43,9%). Todas as cepas de STEC formaram biofilmes com valores de densidade ótica entre 0,209 e 3,251. Também, os 54,4% (31/57) das estirpes STEC foram classificados como fortes formadores de biofilmes. A habilidade de formação de biofilmes de STEC constitui um risco evidente na transmissão deste patógeno ao humano, que deve ser levado em consideração para sua vigilância e controle.

The possibility of early diagnosis of colorectal cancer through expression of Lncrna UCA1, Lncrna LINC00970, and Wnt genes; an in-vitro study

Colorectal cancer is the 4thcause of cancer death; with considering the growth process of this cancer and the necessity of early diagnosis, the purpose of the research is to state the LncRNA 00970, LncRNA UCAI,and the Wntgene before and after the treatment by 5-Azacytidine epigenetic medicine, to reach the biomarker in the very first steps of colorectal cancer. In this experiment, the human colon cancer cell line (HT29) treated with different concentrations of 5-aza-2'-deoxycytidine (5-aza-dC) was utilized to induce DNA demethylation; Quantitative PCR (qPCR) was used to measure LncRNA UCA1and LncRNA LINC00970 and Wntexpression. There was a significant relationship between the expression of LncRNA 00970, LncRNA UCAI,and the Wntgene and its effects on colorectal (p < 0.05). The Wntgene was treated by 1 and 10 of 5-Azacytidine epigenetic medicine, which then experienced decreases. In LncRNA UCAI and LncRNA00970 in dose 1 micromolar of 5-Azacytidine had decrement and increment of expressionrespectively that explains their efficiency but in treatment by dose 10 mM of this medicine, no significant LncRNA expression difference was detected, 5-azacitidine has a direct impact on its target genes and LncRNAs.Therefore, it can be used in the early diagnosis of colorectal cancer.

Research on Molecular Mechanism of Fructus Ligustri Lucidi against Osteoporosis based on Network Pharmacology

Abstract TCMSP platform of systematic pharmacology of traditional Chinese medicine This study aimed to investigate the molecular mechanism of Fructus Ligustri Lucidi (NZZ, Chinese abbreviation) against osteoporosis (OP) by means of network pharmacology.ChemDraw Professional 15.1 software and Molinspiration Smiles database were used to draw the chemical formulas of the components. The active ingredients and related target proteins of NZZ were searched in platform of systematic pharmacology of traditional Chinese medicine database, Drugbank, Therapeutic Target Database, SymMap and other databases. Gene Ontology(GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were carried out on the selected target through Enrichr and KEGG Automatic Annotation databases, and their mechanism was studied. A total of 29 compounds and 140 corresponding targets, including 14 key targets and 14 protein factors in protein-protein interaction core network were obtained. The key targets were tumor necrosis factor(TNF), interleukin(IL)-6R and sestrogen receptor alpha. The number of GO items was 466 (P<0.05), including 399 items of biological process (BP), 54 items of cell composition (MF) and 13 items of molecular function (CC). KEGG pathway enrichment screened 85 signaling pathways (P<0.05), including the IL-17 signaling pathway, TNF signaling pathway, advanced glycation end products and their receptors signaling pathway and cAMP signaling pathway. The active ingredients of NZZ. exert their anti-OP effects through multi-components, multi-targets and multi-pathways, which can provide new evidence for further study of their anti-OP mechanism.

Caracterización molecular de genes de virulencia (lmb, bca y rib) y de resistencia a macrólidos (ermB, ermTR y mefA) en aislamientos clínicos de Streptococcus agalactiae / Molecular characterization of virulence (lmb, bca and rib) and macrolid resistance genes (ermB, ermTR and mefA) in clinical isolates of Streptococcus agalactiae

RESUMEN El objetivo del estudio fue identificar molecularmente los genes de virulencia y resistencia a macrólidos en aislamientos clínicos de Streptococcus agalactiae (EGB), recuperados en 2019 a partir de secreción vaginal (n=9) y orina (n=22), en dos establecimientos de salud de Lima. La identificación y susceptibilidad antimicrobiana se determinaron por el sistema automatizado Vitek® 2, se confirmó la identificación fenotípicamente; la resistencia a macrólidos por el método D-test; la identificación de genes de virulencia (lmb, bca y rib) y de resistencia a macrólidos (ermB, ermTR y mefA) por reacción en cadena de la polimerasa (PCR). El fenotipo y genotipo de resistencia a macrólidos predominante fue cMLSb (12/31) y ermB (11/31), y el gen de virulencia más frecuente fue lmb (23/31). Todos fueron sensibles a penicilina, ampicilina y vancomicina. Estos hallazgos muestran la necesidad de implementar estudios de epidemiología molecular que permitan un adecuado conocimiento y seguimiento de EGB en el Perú.

ABSTRACT The aim of the study was to molecularly identify virulence and macrolide resistance genes in clinical isolates of Streptococcus agalactiae (GBS), recovered in 2019 from vaginal discharge (n=9) and urine (n=22), from two health facilities in Lima. Identification and antimicrobial susceptibility were determined by the Vitek® 2 automated system, identification was confirmed phenotypically; macrolide resistance was determined by the D-test method. Identification of virulence genes (lmb, bca and rib) and macrolide resistance genes (ermB, ermTR and mefA) was carried out by polymerase chain reaction (PCR). The predominant macrolide resistance phenotype and genotype were cMLSb (12/31) and ermB (11/31); the most frequent virulence gene was lmb (23/31). All were sensitive to penicillin, ampicillin and vancomycin. These findings show the need to implement molecular epidemiology studies that allow adequate knowledge and follow-up of GBS in Peru.

Síndrome de Noonan asociado a mutación del gen SOS1, reporte de caso / Noonan syndrome associated with a mutation of the SOS1 gene, case report

Introducción: El síndrome de Noonan es un trastorno genético de herencia autosómica dominante con una expresión fenotípica variable. Se encuentra dentro de las enfermedades conocidas como rasopatías, producidas por las mutaciones en los genes RAS. Los pacientes se caracterizan por dismorfismo facial, talla baja, enfermedad cardíaca congénita, alteraciones músculos esqueléticas y en algunos casos discapacidad intelectual. Caso clínico: En el presente reporte se describe el caso de un paciente masculino de un mes de edad que acude a consulta externa, presentando dismorfismo facial y estenosis pulmonar, por lo que se realiza un seguimiento multidisciplinario por sospecha de Síndrome de Noonan. A partir del cuarto mes desarrolló linfedema en la zona del deltoides. Evolución: A los 7 meses de vida se realiza secuenciación de exoma, encontrando una variante patogénica en el gen SOS1, confirmando el diagnóstico de dicho síndrome. Conclusión: Este caso documenta la presencia de síndrome de Noonan con mutación del gen SOS1 con dismorfología facial típica, estenosis de la válvula pulmonar, criptorquidia y displasia linfática con linfedema del deltoides, hallazgo no descrito en casos previos.

Introduction: Noonan syndrome is a dominant autosomal inherited ge-netic disorder with variable phenotypic expression. It is found within diseases known as rasopathies and is pro-duced by mutations in RAS genes. Patients are character-ized by facial dysmorphism, short stature, congenital heart disease, musculoskeletal disorders, and, in some cases, intellectual disability. Clinical case: This report describes the case of a one-month-old male patient who comes to the outpatient clinic, presenting with facial dysmorphism and pulmonary steno-sis, for which a multidisciplinary follow-up is carried out due to suspicion of Noonan syndrome. From the fourth month, the patient developed lymphedema in the deltoid area. Evolution: At 7 months of age, exome sequencing was per-formed, finding a pathogenic vari-ant in the SOS1 gene and confirming the diagnosis of this syndrome. Conclusion: This case documents the presence of Noonan syndrome with a mutation of the SOS1 gene with typical facial dysmorphology, pulmonary valve stenosis, cryptor-chidism and lymphatic dysplasia with deltoid.

Detección de mutaciones del Gen KRAS en pacientes paraguayos con cáncer colorrectal / Detection of KRAS Gene mutations in paraguayan patients with colorectal cancer

El estado mutacional del KRAS ha sido considerado como biomarcador para tratamientos biológicos tras varios ensayos clínicos realizados en pacientes con cáncer colorrectal metastásico. Reportes recientes indican que las frecuencias de mutación del gen KRAS en pacientes con CCR de Asia, Europa y Latinoamérica están entre el 24%, 36% y 40%, respectivamente. Paraguay no cuenta con este tipo de informes, a pesar de registrar anualmente en promedio 75 nuevos casos de pacientes diagnosticados con CCR sólo en el Servicio de Cirugía General del Hospital Central del Instituto de Previsión Social (IPS). El presente trabajo ha implementado este análisis de rutina, prerrequisito obligatorio para la administración de fármacos basados en anticuerpos terapéuticos, y revelado una frecuencia de mutación del gen KRAS del 34% en pacientes paraguayos con CCR que acuden a los Servicios del Hospital Central del IPS

The mutational status of the KRAS has been consider as a biomarker for biological treatments after several clinical trials carried out in patient with metastatic colorectal cancer. Recent reports indicate that the KRAS gene mutation frequencies in CRC patients from Asia, Europe, and Latin America are between 24%, 36%, and 40%, respectively. Paraguay does not have this kind of reports, despite registering an average of 75 new cases of patients diagnosed with CRC per year only in the General Surgery Service of the "Central Hospital - Instituto de Prevision Social (IPS)". The present work has implemented this routine analysis, a mandatory prerequisite for the administration of drugs based on therapeutic antibodies and revealed a KRAS gene mutation frequency of 34% in Paraguayan patients with CRC who attend the IPS Central Hospital Services

Caracterização de polimorfismos nos genes OPG, RANK e RANKL em uma população brasileira / Characterization of OPG, RANK and RANKL gene polymorphisms in a Brazilian population

Introdução: o sistema RANKL (receptor-ativador do fator nuclear-ligante κB)/RANK (receptor ativador do NF-kB)/OPG (osteoprotegrina) Introdução: o sistema OPG (osteoprotegrina)/RANK (receptor ativador do NF-kB)/RANKL (receptor-ativador do fator nuclear-ligante κB) regula os processos fisiológicos e patológicos da remodelação óssea. Polimorfismos genéticos nos genes OPG, RANK e RANKL têm sido associados a doenças, em diferentes populações. Objetivo: Descrever a frequência e o potencial regulatório dos polimorfismos do sistema OPG, RANK e RANKL em uma população brasileira; avaliar o seu potencial como marcadores genéticos informativos de ancestralidade; comparar com patologias associadas em outras populações. Metodologia: neste estudo, 506 indivíduos adultos, participantes de uma coorte acometidos de asma e periodontite, tiveram o DNA genômico extraído e genotipado, utilizando-se a plataforma Illumina. As plataformas NCBI, RegulomeDB, Haploview 4.2 e rSNPBase foram consultadas e utilizadas para análises. Resultados e Discussão: os polimorfismos mais frequentes na população estudada foram o rs3102724 no gene OPG, com frequência de menor alelo (MAF) de 46%; o rs4941129 em RANK, MAF 50%; e o rs9525641 em RANKL, MAF 46%. Os rs3134063 (1f) em OPG, rs17069898 (1f) em RANK e rs2200287 (1d) em RANKL apresentaram maior impacto funcional. Em OPG e RANK, nove polimorfismos se caracterizaram como marcadores genéticos informativos de ancestralidade, com predomínio nas populações YRI (africanos) e CEU (europeus). Os nove polimorfismos, com função intrônica, apresentaram MAF entre 2 a 46% na população-alvo e foram associados a patologias do metabolismo ósseo em outras populações. Conclusão: polimorfismos dos genes estudados se mostraram frequentes na população estudada e tiveram seus alelos mais frequentes associados a doenças em populações ancestrais. Sugere-se que sejam realizados mais estudos.

Introduction: The OPG (osteoprotegerin)/ RANK (NF-kB activating receptor)/ RANKL (nuclear-binding factor κB receptor-activating system regulates the physiological and pathological processes of bone remodeling. Genetic polymorphisms (SNPs) in OPG, RANK and RANKL genes have been associated with diseases in different populations. Objective: Describe the regulatory frequency and potential of SNPs in OPG, RANK and RANKL in a Brazilian population; assess their potential as informative genetic markers of ancestry; compare with pathologies associated with these polymorphisms in other populations. Methods: in this study, 506 adult individuals, participating in a cohort involving asthma and periodontitis, had genomic DNA extracted and genotyped using the Illumina platform. The NCBI, RegulomeDB, Haploview 4.2 and rSNPBase platforms were consulted and used for analysis. Results and discussion: the most frequent polymorphisms in the studied population were the rs3102724 in the OPG gene, with the lowest allele frequency (MAF) of 46%; rs4941129 in RANK, MAF 50% and rs9525641 in RANKL, MAF 46%. The rs3134063 (1f) in OPG, rs17069898 (1f) in RANK and rs2200287 (1d) in RANKL, had greater functional impact. In OPG and RANK, 9 SNPs were characterized as informative genetic markers of ancestry, predominantly in YRI (African) and CEU (European) populations. These 9 SNPs, with intronic function, presented MAF between 2 and 46% in our population, and were associated with pathologies in bone metabolism in other populations. Conclusion: SNPs of the studied genes were found to be frequent in the studied population and had their most frequent alleles associated with diseases in ancestral populations. It is suggested that further studies be carried out

Mutação do promotor TERT no carcinoma anaplásico da tireoide: um relato de caso / TERT promoter mutation in anaplastic thyroid carcinoma: a case report

Introdução: o gene TERT codifica a subunidade catalítica da telomerase responsável pelo alongamento dos telômeros no final dos cromossomos. Mutações na região promotora do gene TERT resultam em superexpressão da subunidade catalítica e promovem aumento da atividade da telomerase, fatos que levam ao aumento da incidência do câncer. No carcinoma anaplásico da tireoide, essas mutações são preditores de pior prognóstico e estão associadas a comportamento clínico agressivo, incluindo alta frequência de recidivas, metástases a distância e morte específica pela doença. Objetivo: relatar o caso de uma paciente idosa portadora de carcinoma anaplásico da tireoide, cujo teste de sequenciamento genético revelou a mutação do promotor TERT C228T. Caso clínico: mulher idosa, 66 anos, diagnosticada inicialmente com nódulo tireoidiano, o qual cresceu rapidamente em um curto período de tempo. Diante da suspeita de neoplasia maligna, a paciente foi submetida a tireoidectomia total, com realização de esvaziamento cervical. Os estudos anatomopatológico e imuno-histoquímico do tumor confirmaram o carcinoma. Estudos moleculares realizados a partir da tecnologia do sequenciamento de nova geração negaram a presença de fusões gênicas, porém detectaram a mutação TERT C228T. Discussão: a identificação da mutação no promotor TERT C288T reforça a hipótese de que mutações TERT são frequentes em tumores tireoidianos mais agressivos, como é o caso do carcinoma anaplásico da tireoide. Conclusão: os dados apresentados neste estudo reforçam a premissa de que mutações no promotor TERT são preditores de pior prognóstico e de comportamento clínico mais agressivo.

Introduction: the TERT gene encodes the catalytic telomerase subunit responsible for elongating telomeres at the end of chromosomes. Mutations in the promoter region of the TERT gene result in overexpression of the catalytic subunit and promote increased telomerase activity, facts that lead to an increased incidence of cancer. In anaplastic thyroid carcinoma, these mutations are predictors of worse prognosis and are associated with aggressive clinical behavior, including a high frequency of relapses, distant metastases, and diseasespecific death. Objective: to report the case of an elderly patient with anaplastic thyroid carcinoma, whose gene sequencing test revealed a TERT C228T promoter mutation. Case report: Elderly woman, 66 years old, initially diagnosed with a thyroid nodule, which grew rapidly in a short period of time. Given the suspicion of malignant neoplasm, the patient underwent total thyroidectomy, with neck dissection. The anatomopathological and immunohistochemical studies of the tumor confirmed the carcinoma. Molecular studies performed using next-generation sequencing technology denied the presence of gene fusions, but detected the TERT C228T mutation. Discussion: identification of the mutation in the TERT C288T promoter reinforces the hypothesis that TERT mutations are frequent in more aggressive thyroid tumors, such as anaplastic thyroid carcinoma. Conclusion: data presented in this study reinforce the premise that mutations in the TERT promoter are predictors of worse prognosis and more aggressive clinical behavior.

Caracterización molecular de enterobacterias multirresistentes en dos departamentos de la selva peruana / Molecular characterization of multiresistant enterobacteria in two departments of the Peruvian jungle

Resumen | Introducción. La aparición de enterobacterias multirresistentes y productoras de betalactamasas de espectro extendido (BLEE) en pacientes de consulta externa con infecciones urinarias, representa un problema de salud pública en Perú. Objetivos. Caracterizar molecularmente enterobacterias multirresistentes aisladas de pacientes con diagnóstico de infección urinaria y procedentes de dos departamentos de la selva peruana. Materiales y métodos. Se hizo un estudio descriptivo, observacional y retrospectivo de 61 aislamientos de urocultivo procedentes de la selva peruana durante 2017 y 2018. Los perfiles de resistencia se identificaron utilizando el sistema automatizado MicroScan™ y para la detección de los genes blaTEM, blaCTX-M, blaSHV se empleó una reacción en cadena de la polimerasa (PCR) convencional. Resultados. Las enterobacterias positivas para BLEE más frecuentes por departamento fueron Escherichia coli en Madre de Dios (25 %, 10/40) y Ucayali (76,2 %, 16/21). En ambos departamentos, el gen blaCTX-Mfue el más frecuente (25/61; 41 %), seguido por blaTEM(15/61; 24,6 %) y blaSHV (10/61; 16,4 %). En el perfil de sensibilidad antimicrobiana, se detectó 72,6 % de resistencia contra ampicilina, 82,3 % contra cefalotina y 88,7 % contra nitrofurantoína. Conclusiones. El porcentaje de cepas de enterobacterias multirresistentes productoras de BLEE en ambos departamentos fue del 57,4 % y el gen bla CTX-M fue el más frecuente.

Abstract | Introduction. The emergence of multiresistant enterobacteria producing extended-spectrum beta-lactamase (ESBL) in outpatients with urinary tract infections represents a public health problem in Perú. Objectives. To characterize multiresistant enterobacteria isolated from patients diagnosed with urinary tract infection in two Peruvian jungle departments using molecular techniques. Materials and methods. We conducted a descriptive, observational, and retrospective study of 61 urine culture isolates from two departments in the Peruvian jungle during 2017-2018. Resistance profiles were identified using the MicroScan™ automated system and a conventional polymerase chain reaction (PCR) was used for the detection of blaCTX-M, blaTEMand blaSHV genes. Results. The most common positive ESBL enterobacteria for each department were Escherichia coli in Madre de Dios (10/40; 25%) and Ucayali (16/21; 76.2%). Gene blaCTX-Mwas the most prevalent in both departments (25/61; 41%), followed by blaTEM (15/61; 24.6%), and blaSHV (10/61; 16.4%). As for the antimicrobial susceptibility profile, we detected resistance levels of 72.6% for ampicillin, 82.3% for cephalothin, and 88.7% for nitrofurantoin. Conclusions. BLEE-producing multi-resistant enterobacteria strains in both departments were 57.4% and blaCTX-M was the most common gene.

ß-l; -lactamasas AmpC en bacilos gramnegativos de aislados clínicos en un centro hospitalario de tercer nivel en Colombia / AmpCß-l;-lactamases in Gram-negative bacilli from clinical isolates in a Colombian tertiary hospital

Introdución: Las ß-lactamasas AmpC son enzimas con capacidad hidrolítica, pueden ser de tipo constitutivo o inducible. No existe un método estandarizado para su determinación fenotípica por normas internacionales; la detección de estas mediante el uso de la biología molecular podría ser una alternativa útil para vigilancia y control de la diseminación de clones circulantes en el entorno hospitalario. Objetivo: Determinar el fenotipo de resistencia y genes expresados en la producción de ß-lactamasas AmpC en bacilos gramnegativos de aislados clínicos en un centro hospitalario. Métodos: Estudio observacional, descriptivo y de corte transversal. Se seleccionaron 78 cepas bacterianas como portadoras de ß- lactamasas AmpC. Se les realizó prueba de aproximación de disco; a las cepas con resultado positivo se seleccionaron para extracción de ADN y PCR multiplex para detección de 6 familias genes AmpC. Se determinó la frecuencia por tipo de muestra, servicio y comparación con el perfil de susceptibilidad. Resultados: De las cepas seleccionadas con fenotipo AmpC, el 57,6 por ciento (45/78) se consideró caso confirmado ß-lactamasas AmpC por su positividad para la prueba confirmatoria. La técnica molecular utilizada confirmó en el 40 por ciento (18/45) la presencia de genes AmpC. Se obtuvo con mayor frecuencia el gen MIR n= 9 (20 por ciento), seguido de DHA n= 7 (15 por ciento). Conclusiones: La detección oportuna de genes que codifican para ß-lactamasas AmpC permite establecer estrategias para evitar la circulación mediada por plásmidos en hospitales, así como utilizar mejores opciones terapéuticas que no induzcan a otros mecanismos de resistencia(AU)

Introduction: AmpC ß--lactamases are enzymes with hydrolytic activity. They may be either constitutive or inducible. No standardized method is available for their phenotypical determination by international standards. Their detection by molecular biology could be a useful alternative for the surveillance and control of the spread of clones circulating in hospital environments. Objective: Determine the resistance phenotype and genes expressed in the production of AmpC ß-lactamases in Gram-negative bacilli from clinical isolates in a hospital. Methods: An observational descriptive cross-sectional study was conducted. A total 78 bacterial strains were selected as carriers of AmpC ß-lactamases. Disc approximation tests were performed. The strains testing positive were selected for DNA extraction and multiplex PCR for detection of six AmpC gene families. Determination was made of the frequency per sample type, service and comparison with the susceptibility profile. Results: Of the strains selected with AmpC phenotype, 57.6 percent (45/78) were considered to be AmpC β-lactamase confirmed cases, due to their positive confirmatory test. The molecular technique used confirmed the presence of AmpC genes in 40 percent (18/45) of the cases. The gene most commonly obtained was MIR n= 9 (20 percent), followed by DHA n= 7 (15 percent). Conclusions: Timely detection of genes encoding for AmpC ß-lactamases makes it possible to set up strategies to prevent plasmid-mediated circulation in hospitals, as well as apply better therapeutic options that do not induce other resistance mechanisms(AU)

Angioedema hereditário inaugural na idade pediátrica / Hereditary angioedema in a child with no family history of disease

O angioedema hereditário por défice de C1-inibidor é uma doença rara autossômica dominante com uma prevalência estimada em 1:50.000. Habitualmente a história familiar aponta para este diagnóstico. No entanto, a apresentação atípica com história familiar negativa pode atrasar o diagnóstico de meses a anos. Os autores apresentam o caso de uma criança de 6 anos sem antecedentes pessoais ou familiares relevantes que recorreu ao Serviço de Urgência pediátrico por edema, calor e rubor do cotovelo, joelho e maléolos direitos com 12h de evolução, sem fatores associados. Ao exame objetivo: edema do cotovelo, joelho e maléolos direitos, exantema não pruriginoso maleolar homolateral com discreto desconforto à palpação. Sem elevação dos parâmetros infeciosos ou inflamatórios. Foi iniciada corticoterapia sistêmica, com melhoria lenta do quadro. Teve alta, referenciada à consulta de Imunoalergologia. Na anamnese foram apurados quatro episódios de edema periarticular nos doze meses prévios. A avaliação analítica da criança revelou C1 inibidor 62 mg/dL, C1 inibidor funcional 29%, confirmada em duas determinações, e a dos pais e dos dois irmãos foi normal. No estudo genético não foram identificadas mutações nos genes SERPING. O angioedema hereditário por défice de função do C1-inibidor - tipo II - representa 15 a 20% dos casos. Embora a história familiar seja o maior sinal de alerta para o diagnóstico desta patologia, em 20-25% dos casos ocorre mutação espontânea. Nestes casos um elevado grau de suspeição é necessário e um atraso no diagnóstico pode levar a consequências graves. As opções terapêuticas em crianças menores de 12 anos são ainda limitadas.

Hereditary angioedema with C1-inhibitor deficiency is a rare autosomal dominant disease with an estimated prevalence of 1:50 000. Usually, family history points to this diagnosis. However, atypical presentation with negative family history may delay diagnosis in months to years. The authors describe the case of a 6-year-old girl with apparently no significant family or past medical history, presenting to the emergency department for edema, warmth, and redness of the right elbow, knee, and ankle, which started 12 hours earlier, without associated factors. On physical examination, edema of the right elbow, knee, and ankle, and nonpruritic rash on the right ankle with a slight discomfort on palpation were found. Laboratory infection or inflammation markers were not elevated. Systemic corticosteroids were started, with slow improvement. She was discharged and referred to an immunoallergology outpatient clinic. On medical history taking, four episodes of periarticular edema in the past 12 months were identified. Laboratory evaluation revealed C1-inhibitor at 62 mg/dL and functional C1-inhibitor at 29%, confirmed in two samples; the parents and two siblings were normal. On genetic testing, there were no mutations on the SERPING genes. Hereditary angioedema with C1-inhibitor deficiency ­ ie, type II ­ accounts for 15 to 20% of cases. Even though family history is the major indicator for diagnosis of this condition, a de novo mutation occurs in 20 to 25% of cases. In these cases, a high suspicion is necessary, and a delayed diagnosis could have severe implications. Therapeutic options in children under the age of 12 are limited.

Evaluación de la metilación del DNA en tejidos de cáncer colorrectal fijados en formalina y embebidos en parafina (FFPE) / Evaluation of DNA methylation in formalin-fixed, paraffin embedded colorectal cancer tissues (FFPE)

Resumen Las alteraciones en la metilación de dinucleótidos CpG en regiones promotoras es uno de los mecanismos epigenéticos implicados en cáncer que tiene uso potencial como biomarcador. Su evaluación, a partir de tejidos fijados en formalina y embebidos en parafina (FFPE), representa un gran desafío dadas la degradación parcial, el entrecruzamiento y las bajas cantidades del DNA obtenido. En esta nota técnica, describimos un protocolo para el estudio del estado de metilación del promotor distal del proto-oncogén K-RAS, a partir de varias muestras obtenidas de dos tejidos FFPE de cáncer colorrectal con antigüedad de 11 años. Se empleó un protocolo de conversión con bisulfito alternativo al usual; se usó una DNA polimerasa modificada y una PCR anidada y se optimizó la secuenciación directa del DNA convertido con bisulfito. Este protocolo podría ser aplicado para determinar estados de metilación en otros genes y tipos de cáncer en tejidos FFPE.

Abstract Alterations in the methylation of CpG dinucleotides in promoter regions is one of the epigenetic mechanisms involved in cancer that has potential use as a biomarker. Its evaluation from formalin-fixed and paraffin-embedded (FFPE) tissues represents a great challenge given the partial degradation, crosslinking, and low amounts of the obtained DNA. In this technical note we describe a protocol for the study of the methylation status of the distal promoter of the K-RAS proto-oncogene from several samples obtained from two 11-years old FFPE tissues of colorectal cancer. An alternative bisulfite conversion protocol to the usual one was used; a modified DNA polymerase and a nested PCR were used and the direct sequencing of the converted DNA with bisulfite was optimized. This protocol could be applied to determine methylation states in other genes and types of cancer.

Genética del hipotiroidismo congénito / The genetics of congenital hypothyroidism

Se realizó una revisión narrativa sobre la genética del hipotiroidismo congénito (HC). Se utilizaron las bases de datos Medline/PubMed, LILACS-BIREME y SciELO. Se identificaron los estudios originales publicados entre 2000 y agosto de 2020. Las palabras clave utilizadas durante la búsqueda fueron las siguientes: "hipotiroidismo congénito (congenital hypothyroidism)", "genética (genetic)", "polimorfismos de nucleótido único (SNP) (single polymorphisms nucleotid)". Se revisaron 58 estudios originales que informan las bases moleculares del HC. Se ha definido el concepto básico del HC, así como las bases moleculares que están asociados con la aparición de dicho trastorno. La revisión de la literatura ha permitido identificar al menos 12 genes que codifican las proteínas, las cuales, al producirse mutaciones, están implicadas en el HC. De los 12 genes informados que desempeñan un papel importante en el HC, errores en 6 genes se han vinculado con el HC con disgenesia tiroidea, lo cual implica alteraciones en la morfogénesis de la glándula tiroides, mientras que mutaciones en otros 6 genes se han asociado con dishormonogénesis, que genera un bloqueo total o parcial de los procesos bioquímicos implicados en la síntesis y secreción de hormonas tiroideas. La prevalencia en Sudamérica varía aproximadamente desde 1 por cada 1170 hasta 1 por cada 8285 neonatos. El estudio de la genética molecular pone de manifiesto que, en el futuro, aportará datos importantes en cuanto a la identificación de nuevas mutaciones y asociaciones con fenotipos clínicos que podrían relacionarse con el HC, para, de esta manera, potenciar el diagnóstico y tratamiento

A narrative review was conducted on the genetics of congenital hypothyroidism. The Medline/PubMed, LILACS-BIREME, and SciELO databases were used. Original studies published between 2000 and August 2020 were identified. The keywords used during the search were as follows: "congenital hypothyroidism", "genetics", "polymorphisms SNPs". Fifty-eight original studies reviewing the molecular basis of congenital hypothyroidism were reviewed. The basic concept of congenital hypothyroidism has been defined as well as the molecular bases that are associated with the development of this disorder. The literature review has identified at least 12 genes encoding proteins that, when mutations occur, are involved in congenital hypothyroidism. Of the 12 genes reported to play an important role in congenital hypothyroidism, errors in 6 genes have been associated with congenital hypothyroidism with thyroid dysgenesis, which implies alterations in the morphogenesis of the thyroid gland. On the other hand, mutations in 6 other genes have been associated with dyshormonogenesis that generates a total or partial blockage of the biochemical processes involved in the synthesis and secretion of thyroid hormones. The prevalence in South America is reported to vary from approximately 1 per 1000 to 1 per 8000 newborns. The study of molecular genetics shows that in the future it will contribute to the identification of new mutations and associations with clinical phenotypes that could be related to congenital hypothyroidism, thus enhancing diagnosis and treatment