RESUMO
TwinsMX registry is a national research initiative in Mexico that aims to understand the complex interplay between genetics and environment in shaping physical and mental health traits among the country's population. With a multidisciplinary approach, TwinsMX aims to advance our knowledge of the genetic and environmental mechanisms underlying ethnic variations in complex traits and diseases, including behavioral, psychometric, anthropometric, metabolic, cardiovascular and mental disorders. With information gathered from over 2800 twins, this article updates the prevalence of several complex traits; and describes the advances and novel ideas we have implemented such as magnetic resonance imaging. The future expansion of the TwinsMX registry will enhance our comprehension of the intricate interplay between genetics and environment in shaping health and disease in the Mexican population. Overall, this report describes the progress in the building of a solid database that will allow the study of complex traits in the Mexican population, valuable not only for our consortium, but also for the worldwide scientific community, by providing new insights of understudied genetically admixed populations.
Assuntos
Interação Gene-Ambiente , Sistema de Registros , Humanos , México/epidemiologia , Masculino , Feminino , Adulto , Doenças em Gêmeos/genética , Doenças em Gêmeos/epidemiologia , Pessoa de Meia-Idade , Gêmeos Monozigóticos/genética , Gêmeos Dizigóticos/genética , Transtornos Mentais/genética , Transtornos Mentais/epidemiologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/epidemiologiaRESUMO
Here, we report the clinical observations of two Chinese fraternal twins who presented with severe dehydration, poor feeding, and absence of stimuli responses within a few days of birth. Trio clinical exome sequencing of the family identified compound heterozygous intronic variants (c.1439+1G>C and c.875+1G>A ) in SCNN1A gene in these two patients. Sanger sequencing results showed that the c.1439+1G>C variant was inherited from the mother, and c.875+1G>A from the father, rarely reported in pseudohypoaldosteronism type 1 with sodium epithelial channel destruction (PHA1b) patients. Case 2 received timely symptomatic treatment and management after obtaining these results, which improved the clinical crisis. Our results suggest that the compound heterozygous splicing variants in SCNN1A were responsible for PHA1b in these Chinese fraternal twins. This finding extends the knowledge of the variant spectrum in PHA1b patients and highlights the application of exome sequencing in critically ill newborns. Finally, we discuss supportive case management, particularly in maintaining blood potassium concentration.
Assuntos
Pseudo-Hipoaldosteronismo , Humanos , Recém-Nascido , População do Leste Asiático , Mutação , Pseudo-Hipoaldosteronismo/genética , Gêmeos Dizigóticos/genéticaRESUMO
Heteropaternal superfecundation is an extremely rare phenomenon that occurs when a second ova released during the same menstrual cycle is additionally fertilized by the sperm cells of a different man in separate sexual intercourse. In August, 2018, the Grupo de Genética de Poblaciones e Identificación at Universidad Nacional de Colombia received a request to establish the paternity of a pair of male twins with genetic markers. The following analyses were performed: amelogenin gene, autosomal short tandem repeat (STR), and Y-STR analyses by means of human identification commercial kits, paternity index, and the probability of paternity calculation and interpretation. A paternity index of 2.5134E+7 and a probability of paternity of 99.9999% for twin 2 were obtained while 14 out of 17 Y-chromosome markers and 14 out of 21 autosomal short tandem repeats were excluded for twin 1. The results indicated that the twins have different biological fathers. Although heteropaternal superfecundation is rarely observed among humans given its low frequency, in paternity disputes for dizygotic twins it is mandatory to demand the presence of the two twins in the testing to avoid wrong conclusions.
La superfecundación heteropaternal es un fenómeno extremadamente raro que se produce cuando un segundo óvulo, liberado durante el mismo ciclo menstrual, es fertilizado por un espermatozoide de un hombre diferente en relaciones sexuales separadas. En agosto de 2018, el Grupo de Genética de Poblaciones e Identificación de la Universidad Nacional de Colombia recibió una solicitud para establecer la paternidad mediante marcadores genéticos de un par de mellizos varones, en quienes se hizo el análisis del gen de amelogenina, el análisis de repeticiones cortas en tándem (Short Tandem Repeats, STR) autosómicas y del cromosoma Y (Y-STR) mediante kits comerciales de identificación humana y cálculos e interpretación del índice de paternidad y probabilidad de paternidad. Se obtuvo un índice de paternidad de 2,5134E+7 y una probabilidad de paternidad de 99,9999 % para el gemelo 2, en tanto que en el gemelo 1 se excluyeron 14 de los 17 marcadores del cromosoma Y y 14 de los 21 sistemas STR autosómicos evaluados. Los resultados indicaron que los gemelos tienen diferentes padres biológicos. A pesar de que la superfecundación heteropaternal rara vez se observa en humanos debido a su baja frecuencia, en las disputas de paternidad para los gemelos dicigóticos, es obligatorio exigir en la prueba la presencia de los dos gemelos para evitar conclusiones incorrectas.
Assuntos
Repetições de Microssatélites/genética , Paternidade , Superfetação/genética , Gêmeos Dizigóticos/genética , Amelogenina/genética , Cromossomos Humanos Y/genética , Colômbia , Pai , Feminino , Marcadores Genéticos , Humanos , Masculino , GravidezRESUMO
Despite the well-known relevance of twin studies in the medical and social sciences and the growing number of twin registries throughout the world, Latin America has not fully incorporated into the twin research community. We describe the first steps taken toward developing a twin registry in Mexico: its aim, organization, recruiting potential and main short-term objectives.
Assuntos
Doenças em Gêmeos/epidemiologia , Doenças em Gêmeos/genética , Sistema de Registros/estatística & dados numéricos , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , México/epidemiologia , Pais , Seleção de Pacientes , Inquéritos e QuestionáriosRESUMO
The University of São Paulo Twin Panel (Painel USP de Gêmeos), based at the Institute of Psychology of the University of São Paulo, started formally in 2017. Our registry is new, but in only two years of formal existence, it comprises a volunteer sample of 4826 registered individuals (98% twins and 2% higher-order multiples), recruited at the University of São Paulo and by social media campaigns. Our main aim is to conduct and promote research with twins on psychological processes and behavior. The University of São Paulo is the largest higher education and research institution in South America, and the Painel USP de Gêmeos has great potential for fostering research on twin-related issues from a psychological perspective in Brazil and South America.
Assuntos
Pesquisa Comportamental , Doenças em Gêmeos/psicologia , Sistema de Registros/estatística & dados numéricos , Projetos de Pesquisa/normas , Gêmeos Dizigóticos/estatística & dados numéricos , Gêmeos Monozigóticos/estatística & dados numéricos , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Doenças em Gêmeos/epidemiologia , Doenças em Gêmeos/genética , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Participação do Paciente , Seleção de Pacientes , Gêmeos Dizigóticos/genética , Gêmeos Dizigóticos/psicologia , Gêmeos Monozigóticos/genética , Gêmeos Monozigóticos/psicologia , Adulto JovemRESUMO
TwinsMX is a national twin registry in Mexico recently created with institutional support from the Universidad Nacional Autónoma de México. It aims to serve as a platform to advance epidemiological and genetic research in the country and to disentangle the genetic and environmental contributions to health and disease in the admixed Mexican population. Here, we describe our recruitment and data collection strategies and discuss both the progress to date and future directions. More information about the registry is available on our website: https://twinsmxofficial.unam.mx/ (content in Spanish).
Assuntos
Doenças em Gêmeos/epidemiologia , Doenças em Gêmeos/genética , Interação Gene-Ambiente , Sistema de Registros/estatística & dados numéricos , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Seleção de Pacientes , Adulto JovemRESUMO
The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.
Assuntos
Doenças em Gêmeos/epidemiologia , Sistema de Registros , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adulto , Austrália , Brasil , Doenças em Gêmeos/genética , Feminino , Humanos , Estudos Longitudinais , Masculino , Inquéritos e QuestionáriosRESUMO
The interrelatedness between twin research and the arts is explored via a new play about a famous case. In the 1960s, identical twin David Bruce Reimer was accidentally castrated as an infant during circumcision to correct a urinary problem. The decision to raise him as a girl, and the consequences of that decision, are explored in the new theatrical production of Boy. Other examples of the arts mirroring science, and vice versa, are described. Next, brief reviews and summaries of twin research on sexual orientation, 1860s' knowledge of placental arrangements and twinning mechanisms, and genes underlying multiple birth conception and fertility related measures are provided. This article concludes with a look at twins on college campuses and the identification of individuals by their brain waves. A correction and clarification regarding my article on the Brazilian Twin Registry in the last issue of THG (Segal, 2016) is also provided.
Assuntos
Arte , Comportamento Sexual , Estudos em Gêmeos como Assunto , Gêmeos Dizigóticos/genética , Ondas Encefálicas , Brasil , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Gravidez , Gravidez Múltipla , Universidades , Adulto JovemRESUMO
OBJECTIVE: To determine the genetic contribution to risk for respiratory distress syndrome (RDS) among moderately preterm, late preterm, and term infants (estimated gestational age ≥32 weeks) of African- and European-descent. STUDY DESIGN: We reviewed clinical records for 524 consecutive twin pairs ≥32 weeks gestation. We identified pairs in which at least 1 twin had RDS (n = 225) and compared the concordance of RDS between monozygotic and dizygotic twins. Using mixed-effects logistic regression, we identified covariates that increased disease risk. We performed additive genetic, common environmental, and residual effects modeling to estimate genetic variance and used the ratio of genetic variance to total variance to estimate genetic contribution to RDS disease risk. RESULTS: Monozygotic twins were more concordant for RDS than dizygotic twins (P = .0040). Estimated gestational age, European-descent, male sex, delivery by cesarean, and 5-minute Apgar score each independently increased risk for RDS. After adjusting for these covariates, genetic effects accounted for 58% (P = .0002) of the RDS disease risk variance for all twin pairs. CONCLUSIONS: In addition to environmental factors, genetic factors may contribute to RDS risk among moderately preterm, late preterm, and term infants. Discovery of risk alleles may be important for prediction and management of RDS risk.
Assuntos
Recém-Nascido Prematuro , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Nascimento a Termo , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Feminino , Predisposição Genética para Doença , Idade Gestacional , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Gravidez , Estudos Retrospectivos , Fatores de RiscoRESUMO
Abstract Background: Configuration of the abdominal aorta is related to healthy aging and a variety of disorders. Objectives: We aimed to assess heritable and environmental effects on the abdominal aortic diameter. Methods: 114 adult (69 monozygotic, 45 same-sex dizygotic) twin pairs (mean age 43.6 ± 16.3 years) underwent abdominal ultrasound with Esaote MyLab 70X ultrasound machine to visualize the abdominal aorta below the level of the origin of the renal arteries and 1-3 cm above the bifurcation. Results: Age- and sex-adjusted heritability of the abdominal aortic diameter below the level of the origin of the renal arteries was 40% [95% confidence interval (CI), 14 to 67%] and 55% above the aortic bifurcation (95% CI, 45 to 70%). None of the aortic diameters showed common environmental effects, but unshared environmental effects were responsible for 60% and 45% of the traits, respectively. Conclusions: Our analysis documents the moderate heritability and its segment-specific difference of the abdominal aortic diameter. The moderate part of variance was explained by unshared environmental components, emphasizing the importance of lifestyle factors in primary prevention. Further studies in this field may guide future gene-mapping efforts and investigate specific lifestyle factors to prevent abdominal aortic dilatation and its complications.
Resumo Fundamento: A configuração da aorta abdominal relaciona-se com o envelhecimento saudável e uma série de distúrbios. Objetivos: Avaliar efeitos herdáveis e ambientais no diâmetro da aorta abdominal. Métodos: 114 pares de gêmeos adultos (69 monozigóticos e 45 dizigóticos do mesmo sexo), com idade média de 43,6 ± 16,3 anos, foram submetidos a ultrassonografia abdominal com o aparelho Esaote MyLab 70X para visualização da aorta abdominal abaixo da origem das artérias renais e 1-3 cm acima da bifurcação aórtica. Resultados: A herdabilidade ajustada para idade e sexo do diâmetro da aorta abdominal abaixo da origem das artérias renais foi 40% [intervalo de confiança (IC) 95%, 14 – 67%] e acima da bifurcação, 55% (IC 95%, 45 – 70%). Nenhum dos diâmetros aórticos apresentou efeitos ambientais comuns, mas os efeitos ambientais não compartilhados foram responsáveis por 60% e 45% dos traços, respectivamente. Conclusões: Nossa análise mostrou herdabilidade moderada e diferença do diâmetro da aorta abdominal com especificidade de segmento. A parte moderada da variância foi explicada pelo componente ambiental não compartilhado, enfatizando a importância do estilo de vida na prevenção primária. Estudos adicionais nesse campo poderão guiar futuros esforços de mapeamento genético e investigar fatores específicos de estilo de vida para prevenir dilatação da aorta abdominal e suas complicações.