Manejo de gemelos unidos: experiencia con nueve casos en Medellín, Colombia / Management of conjoined twins: experience with nine cases in Medellín, Colombia

Introducción y metodología: los gemelos siameses son una anomalía muy rara, que ha generado gran interés por el reto que plantea la complejidad de su manejo. Se presenta la experiencia obtenida al respecto durante 40 años en la Sección de Cirugía Pediátrica de la Universidad de Antioquia, Medellín, Colombia, con base en la revisión de las historias clínicas y los archivos personales de los cirujanos de dicha Sección. Resultados: entre 1970 y 2010 se presentaron nueve casos de gemelos siameses, seis de ellos en el Hospital Universitario San Vicente de Paúl y tres en el Instituto de los Seguros Sociales. La distribución fue: tres pares de gemelos asimétricos (parásitos) y seis de gemelos simétricos, a saber: dos de toracoonfopagos, dos de onfaloxigopagos, uno de isquiopagos y uno de pigopagos. Discusión y conclusiones: la separación de los gemelos siameses es de muy rara ocurrencia en la práctica de la cirugía pediátrica. Por esto es importante que las experiencias sean compartidas y publicadas para mejorar los resultados a corto y largo plazo. La experiencia con estos complejos pacientes nos ha dejado enseñanzas como la importancia del diagnóstico prenatal apropiado, del enfoque preoperatorio certero, de la planeación rigurosa del acto quirúrgico y del seguimiento postoperatorio minucioso.

Introduction and methodology: Conjoined twins are a rare anomaly that has generated a great deal of interest because of its complex management. We present the experience achieved during 40 years at the Section of Pediatric Surgery, University of Antioquia, in Medellin, Colombia. Results: In the period between 1970 and 2010, nine cases of conjoined twins were treated by our group, six of them at Hospital Universitario San Vicente de Paúl and three at the Social Security Institute. Their distribution was as follows: three pairs of asymmetric twins (parasites); two pairs of thoracoonphalopagus, two pairs of omphaloxigopagus, one pair of pygopagus and one pair of ischiopagus. Discussion and conclusions: Separation of conjoined twins is a rare situation in the practice of pediatric surgery. Therefore, it is important to share and publish the experience achieved in order to improve the short and long-term outcomes. Our experience has taught us the importance of proper prenatal diagnosis, safe preoperative approach, judicious planning of surgery and rigorous postoperative follow-up.

Advances in research based on twins reared apart / 中华医学遗传学杂志

The design of twins reared apart, very rare genetic epidemiological resources has been hailed as fascinating experiment of nature. However, not so many studies have been based on it due to the difficulty in recruiting the participants. It also makes the only existing research on twins raised apart particularly valuable. How to utilize these resources fully will be the focus of this research area. This review will overview its design background, basic hypothesis, and current status of research and give advice for the research in this field in China.

Contribución de los factores genéticos y ambientales en el desarrollo de la hipertensión arterial en estudios de gemelos en el municipio Chambas / Genetic and environmental factors contribution in hypertension development in studies of twins from Chambas town

Se realizó un estudio observacional analítico transversal, en el municipio Chambas, de Febrero a Abril del 2007 para describir el comportamiento clínico, epidemiológico y genealógico de la Hipertensión Arterial, identificando la contribución de factores genéticos y ambientales en el origen de la enfermedad. El universo incluyó 41 parejas de gemelos. La muestra quedó constituida por 33, donde al menos un miembro del par padecía Hipertensión Arterial, 16 monocigóticos y 17 dicigóticos. La mayor proporción de monocigóticos concordaron para la hipertensión arterial. En ambos tipos de cigocidad predominó el grupo de 45-55 años y 65 años y más, la raza blanca; la edad de debut promedio de la enfermedad fue antes de los 50 años, destacándose el sexo masculino. Entre los factores de riesgo se destaca el sedentarismo, dieta rica en sal y tabaquismo. Predominaron los gemelos con familiares de primer grado afectados. La concordancia para monocigóticos fue de 38 por ciento, en dicigóticos 18 por ciento. Se concluye que mientras mayor es la proporción de genes compartidos en común, mayor es la probabilidad de desarrollar la hipertensión arterial, además de la importancia de los factores de riesgo no genéticos para desarrollar esta enfermedad.

A cross-sectional observational study was carried out, in Chambas municipality, from February to April 2007 for describing the clinical, epidemiological and genealogical Hypertension behavior, identifying the contribution of genetic and environmental factors in the disease origin. The universe included 41 pairs of twins. The sample was composed of 33, where at least one member of pair suffered hypertension, 16 monozygotic and 17 dizygotic twins. Largest proportion of monozygotic agreed to hypertension. In both types of zygosity dominated 45 - 55 years and 65 years and older, white race; the average age of illness onset was before 50 years, particularly males. Among the risk factors highlighted a sedentary lifestyle, high-salt diet and smoking. Twins prevailed with first-degree relatives affected. The monozygotic concordance is 38 percent, 18 percent in dizygotic and the monozygotic probed was 54 percent and 30 percent dizygotic, 48 percent heritability. It concludes that the higher the proportion of genes shared in common, the greater is the likelihood of developing hypertension, and the importance of non-genetic risk factors for developing this disease.

Caracterización de gemelos con esquizofrenia en el municipio de Santiago de Cuba / Characterization of twins with schizophrenia in the municipality of Santiago de Cuba

Se realizó un estudio descriptivo y transversal de 24 pares de gemelos con diagnóstico de esquizofrenia, independientemente de su cigosidad, del municipio de Santiago de Cuba durante el período febrero-abril de 2007, seleccionados mediante un muestreo aleatorio simple, a fin de caracterizarles. Entre las principales observaciones se tuvo en cuenta que la edad promedio de inicio de los síntomas fue más baja en los monocigóticos y los antecedentes prenatales aumentaron el riesgo de la enfermedad. Se constató la existencia de precedentes familiares, con superioridad de los parientes de primer grado. Hubo una mayor frecuencia de concordancia entre gemelos monocigóticos, así como un alto porcentaje en la heredabilidad.

A descriptive and cross-sectional study was conducted in 24 pairs of twins diagnosed with schizophrenia, irrespective of their zygosity, in Santiago de Cuba municipality from February to April, 2007, selected by means of a simple random sampling to characterize them. It was mainly observed that the average age of symptom onset was lower in monozygotic twins and prenatal history increased the risk of disease. The presence of family history was verified, with a predominance of first-degree relatives. There was a higher frequency of concordance between monozygotic twins, as well as a high percentage of heritability.

Epigenetics and its new progress in monozygotic twins / 法医学杂志

Epigenetic, which refers to heritable differences of genes without changing their DNA sequences, is one of the most important biology phenomena in multicellular eukaryotes. Its research contents involves DNA methylation, genomic imprinting, histone acetylation, histone methylation, chromatin remodeling, pseudogene, and microRNA etc. Monozygotic twins is developed from one single zygote and are genetically identical in genomic DNA sequence. From the view of classical genetics, traditional genetic markers such as short tandem repeat and single nucleotide polymorphism can not play important role in discriminating monozygotic twins. So it is very essential to find new genetic markers. Recent achievements made in epigenetics show that there exist striking differences in monozygotic twins and provide a new strategy to discriminate the monozygotic twins. In this paper, the concepts, research contents of epigenetics and its application perspective in discriminating monozygotic twins are reviewed.

O impacto da genética na asma infantil: [revisão] / Impact of genetics in childhood asthma: [review]

OBJETIVO: Apresentar os resultados dos estudos mais importantes e recentes sobre a genética da asma. Estes dados devem auxiliar os clínicos gerais a compreender o impacto da genética sobre este distúrbio complexo e como os genes e polimorfismos influenciam a asma e a atopia. FONTES DOS DADOS: Os dados foram coletados do banco de dados MEDLINE. Os estudos de associação genética foram selecionados do Genetic Association Database, um repositório de estudos de associação genética de doenças e distúrbios complexos organizado pelo National Institutes of Health. SÍNTESE DOS DADOS: Considerando os dados de diversos importantes estudos de gêmeos sobre a genética da asma, a heritabilidade, que mensura a contribuição dos fatores genéticos para a variância da asma, pode ser estimada entre 0,48 e 0,79. Uma grande quantidade de estudos de associação genética tentou identificar genes de susceptibilidade à asma. Os resultados mais replicados nos estudos de associação genética envolvem as cinco regiões do genoma humano a seguir: 5q31-32, 6p21, 11q12-13, 16p11-12, e 20p13. Recentemente, outro gene de susceptibilidade à asma (ORMDL3), considerado determinante crítico para a asma infantil, foi identificado por um estudo genômico de associação. CONCLUSÕES: É possível estimar que a contribuição genética à asma varia entre 48 e 79 por cento. Diversos loci parecem influenciar a susceptibilidade à asma. Os genes localizados no cromossomo 5q (ADRB2, IL13 e IL4) e o gene ORMDL3, no cromossomo 17, identificado recentemente, parecem ser determinantes para a asma infantil. O diagnóstico e a farmacogenética podem ser as primeiras implicações clínicas de estudos extensivos sobre a genética da asma.

OBJECTIVE: To present the most important and recent results of studies on asthma genetics. These data may help general physicians understand the impact of genetics on this complex disorder and how genes and polymorphisms influence asthma and atopy. SOURCES: Data were collected from MEDLINE. Genetic association studies were selected from the Genetic Association Database, which is an archive of human genetic association studies of complex diseases and disorders organized by the National Institutes of Health. SUMMARY OF THE FINDINGS: Considering the data from several important twin studies on asthma genetics, heritability, which measures the contribution of genetic factors to the variance of asthma, may be estimated in 0.48-0.79. A huge number of genetic association studies have been trying to identify asthma susceptibility genes. The most replicated results in the genetic association studies involve the following five regions of the human genome: 5q31-32, 6p21, 11q12-13, 16p11-12, and 20p13. Only recently a new asthma susceptibility gene (ORMDL3) has been identified by a whole genome association study, considered to be a major determinant for childhood asthma. CONCLUSIONS: Genetic contribution to asthma may be estimated ranging from 48 to 79 percent. Several different loci seem to influence asthma susceptibility. Genes located on chromosome 5q (ADRB2, IL13 and IL4) and the recently identified ORMDL3, on chromosome 17, seem to be determinants of childhood asthma. Diagnostics and pharmacogenetics may be the first clinical implication of extensive studies on asthma genetics.

Sirenomelia en neonato gemelo: reporte de un caso y revisión de la literatura / Sirenomelia in a newborn twin: a case report and review

La sirenomelia es una malformación congénita extremadamente rara que se caracteriza por la fusión de ambos miembros inferiores en diversos grados y se presenta un caso por cada 60,000 recién nacidos. Las primeras descripciones médicas y científicas de esta malformación datan desde el renacimiento por autores como Rochéus (1542), Palfun (1553), y Ambroise Paré (1573).

Genetics in eating disorders: extending the boundaries of research / Genética em transtornos alimentares: ampliando os horizontes de pesquisa

OBJECTIVE: To review the recent literature relevant to genetic research in eating disorders and to discuss unique issues which are crucial for the development of a genetic research project in eating disorders in Brazil. METHOD: A computer literature review was conducted in the Medline database between 1984 and may 2005 with the search terms "eating disorders", "anorexia nervosa", "bulimia nervosa", "binge eating disorder", "family", "twin" and "molecular genetic" studies. RESULTS: Current research findings suggest a substantial influence of genetic factors on the liability to anorexia nervosa and bulimia nervosa. Genetic research with admixed populations should take into consideration sample size, density of genotyping and population stratification. Through admixture mapping it is possible to study the genetic structure of admixed human populations to localize genes that underlie ethnic variation in diseases or traits of interest. CONCLUSIONS: The development of a major collaborative genetics initiative of eating disorders in Brazil and South America would represent a realistic possibility of studying the genetics of eating disorders in the context of inter ethnic groups, and also integrate a new perspective on the biological etiology of eating disorders.

OBJETIVO: Revisar a literatura atual concernente à pesquisa genética em transtornos do comportamento alimentar e discutir questões relevantes ao desenvolvimento de um projeto de pesquisa genética nessa área no Brasil. MÉTODO: A revisão realizada utilizou a base de dados Medline, no período de 1984 a maio de 2005, com os seguintes termos de busca: "anorexia nervosa", "bulimia nervosa", "eating disorders", "binge eating disorder", "family studies", "twin studies", "molecular genetics studies". RESULTADOS: Os dados atuais apontam para uma contribuição relevante dos fatores genéticos na suscetibilidade à anorexia e à bulimia nervosa. A pesquisa genética com populações miscigenadas deve levar em consideração o tamanho da amostra, a densidade de genotipagem e a estratificação populacional. Através de "admixture mapping" é possível estimar a estrutura genética destas populações e localizar genes relacionados à variação étnica de doenças ou traços de interesse. CONCLUSÕES: O desenvolvimento de uma grande iniciativa de colaboração em genética de transtornos alimentares no Brasil e na América Latina viabilizará estudar os fatores genéticos em transtornos do comportamento alimentar no contexto de grupos inter-étnicos, e integrar uma nova perspectiva biológica à etiologia destes distúrbios.

overview of the genetic risk of developing schizophrenia in relatives of schizophrenic patients

In this article, we review the recent research evidence of genetic risks in the relatives of patients with schizophrenia, with particular focus on family, twin, adoptive, and gene studies. All current evidence supports a greater role for genetic transmission of vulnerability in the etiology of schizophrenia. Environmental factors appear to play an important role in the timing of expression, the severity and the clinical evolution of the illness

Abulia: no will, no way.

Abulia refers to impaired ability to perform voluntary actions, show initiative, make decisions along with decrease in movements, speech, thought and emotional reactions. We describe here two patients who developed this condition following bilateral insult to different sites in the centromedial core of the brain, the first following the cerebral venous thrombosis and the second after the right ACA and MCA infarct. Both these patients improved following treatment with Bromocriptine. These cases are described for proper identification and management by the clinicians.

Genética de la violencia / The genetics of violence

Esta breve revisión bibliográfica pretende analizar las bases genéticas de la violencia. Se recuerda el concepto de Personalidad Psicopática Antisocial, que implica en su definición actos delictuales, sin pretender que todos los crímenes obedecen a una Personalidad Disfuncional. Siendo el delito un constructo legal se rechaza la idea de que exista una categoría psiquiátrica aplicable a los transgresores de las normas sociales aunque sean recidivantes. Se revisan los estudios entre gemelosmonozigosotos y dizigotos criados juntos o aparte. Se analizaron las investigaciones en gemelos que habían sido adoptados, haciendo énfasis en la influencia del ambiente familiar. Todos estos estudios indican una importante influencia de la herencia en las conductas violentas. Una contribución relevante la hacen los investigadores que postulan una tesis dual, diferenciando, la delincuencia juvenil, que ocurre en la adolescencia y susceptible de rehabilitación, de la delincuencia reincidente cuya conducta agresiva comienza en los primeros años de la vida. Se describen los genes que se han descubierto en familias con conductas violentas y las alteraciones neuroquímicas, que explicarían la agresión observada en un grupo de enfermos esquizofrénicos. Se insiste en que no puede haber un gen de la violencia, que probablemente son múltiples y que la violencia siempre es el resultado de la interacción de las disposiciones hereditarias y de la influencia del ambiente.

Genetic effects on physical growth items of child twins in Han nationality / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyse the heritabilities of physical growth items of body and its related factors.</p><p><b>METHODS</b>An 116 twin pairs of Han nationality, 67 monozygotic (MZ) and 49 like-sex dizygotic (DZ) aged 6 to 12 years, were investigated from June to October in 2004. The measurements included height, weight, sitting height, chest circumference, biacromial breadth and biiliac breadth, and BMI index calculated by the former two measurements. The heritabilities were estimated by using intraclass correlation coefficient method from the adjusted data for age.</p><p><b>RESULTS</b>The intraclass correlation coefficient was greater in the MZ twins than in the DZ twins. The estimated heritabilities of height, weight, BMI, sitting height, chest circumference, biacromial breadth and biiliac breadth were 0.89, 0.88, 0.73, 0.87, 0.78, 0.78, 0.73 in boys and 0.87, 0.74, 0.72, 0.86, 0.62, 0.56, 0.59 in girls adjusted for age. Therefore, there were no sex difference for the heritabilities of height, sitting height and BMI, but the male heritabilities of weight, chest circumference, biacromial breadth and biiliac breadth were higher than the female's respectively.</p><p><b>CONCLUSION</b>Physical growth items should be mainly determined by the genetic factors. There are sex differences for the heritabilities of weight, chest circumference, biacromial breadth and biiliac breadth, i.e., the girls might be affected more easily by environmental factors than the boys in these items.</p>

O papel da genética na dependência do álcool / The role of genetics in alcohol dependence

Este artigo procura examinar a questão da herdabilidade na dependência do álcool. Através da revisão de estudos em famílias, em gêmeos e de adocão, encontramos evidências para afirmar a importância dos fatores genéticos na transmissão da vulnerabilidade a esta dependência. Essa transmissão pode ser melhor compreendida através de um modelo epigenético de desenvolvimento do transtorno, no qual condicões biológicas hereditárias associem-se a situacões ambientais ao longo da vida para a producão da dependência. Neste artigo, apresentamos essas condicões biológicas intermediárias vinculadas ao alto risco para dependência do álcool. Por fim, descrevemos os estudos moleculares que vêm estabelecendo associacões entre polimorfismos e a dependência do álcool, com relevo para o sistema dopaminérgico.

Reconstrucción cardiaca en gemelos toracopagos mediante imagenes de tomografia computada y resonancia magnetica / Cardiac reconstruction in thoracopagus conjoined twins using computarized tomography and magnetic resonance imaging

En Chile las malformaciones congénitas son la segunda causa de mortalidad infantil. La colección de fetos y recién nacidos malformados con que cuenta la Sección de Teratología del Departamento de Anatomía, Facultad de Medicina de la Universidad de Chile, permite conocer y estudiar patologías que, por su baja frecuencia sólo son conocidas por los especialistas. Los gemelos unidos son una condición, en la cual existe predominio en el sexo femenino y su etiología es desconocida. Se estudia el caso, de gemelos unidos del tipo tóraco-onfalópagos, con una fusión amplia desde el esternón hasta la región umbilical, que hubiese requerido de exactitud diagnóstica, para delimitar la interdependencia anatómica y sus posibles consecuencias funcionales, ante una eventual corrección quirúrgica y posible viabilidad. Con este objetivo, se utilizaron técnicas convencionales y avanzadas de imagenología en su estudio, como radiografías, ultrasonografías, TC y RM. Estas dos últimas, se digitalizaron para realizar una reconstrucción anatómica tridimensional in situ con el programa Somavisión.

Heritability of serum lipids and lipoproteins and its related factors in twins aged 5 to 19 years of China / 中华预防医学杂志

<p><b>OBJECTIVES</b>To study the contribution of the genes and environment to variation of serum levels of lipids and lipoprotein.</p><p><b>METHODS</b>One hundred and forty-three healthy monozygotic (MZ) twin pairs and 93 dizygotic (DZ) ones aged 5 to 19 [with a mean of (11.2 +/- 3.4) years]. Microsatellite polymorphism (STR) was used to diagnose zygosity of twins, and intraclass correlation coefficient method and Falconer formula were performed to investigate heritability of serum lipids and lipoproteins unadjusted or adjusted for age and sex. Logarithmic transformation was used for data with skewed distribution. Influence of relevant physical and biochemical indicators on serum lipids and other components was analyzed with partial coefficients of correlation adjusted for age and sex.</p><p><b>RESULTS</b>In the twin samples, difference in serum level of triglycerides (TG) between MZ and DZ was not statistically significant with intraclass variation and intraclass correlation. There was significant difference in serum levels of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and lipoprotein [Lp(a)] between MZ and DZ, with their heritability estimates of 0.56, 0.55, 0.49 and 0.58 unadjusted, respectively, and 0.63, 0.63, 0.55 and 0.64 adjusted for age and sex, respectively. Serum levels of TC, HDL-C, LDL-C and Lp(a) correlated reversely with age. Serum levels of TC, HDL-C and LDL-C in girls were slightly higher than those in boys. Most indicators for serum levels of lipids and lipoprotein, except for serum level of Lp(a) correlated with body mass index (BMI), body fat ratio, Pelidisi index, and other indexes such as blood pressure, blood sugar, serum level of calcium, adjusted for age and sex.</p><p><b>CONCLUSIONS</b>Serum levels of TC, HDL-C and Lp(a) were influenced more greatly by genetic factors, and serum level of TG was mainly influenced by environmental ones. Levels of blood lipids in children were influenced by age and sex, and correlated with indicators that reflect their body fat and nutritional status.</p>

Comparação cefalométrica do complexo craniofacial entre gêmeos monozigóticos / Cephalometric comparison of the craniofacial complex among monozygotic twins

O propósito desta pesquisa foi comparar as variações dos parâmetros cefalométricos horizontais e verticais, anteriores e posteriores, angulares e lineares, inferiores e superiores do complexo craniofacial entre gêmeos monozigóticos. Para execução deste estudo foram utilizadas 36 telerradiografias em norma lateral de 18 pares de gêmeos monozigóticos. Para a execução deste estudo foram utilizadas 36 telerradiografias em norma lateral de 18 pares de gêmeos monozigóticos, brasileiros, leucodermas, sendo 9 pares do gênero masculino, com idades variando entre 8,66 e 13 anos, e 9 pares do gênero feminino, com idades variando entre 7 e 16,16 anos. A seleção da amostra exigia que os indivíduos não tivessem sido submetidos a nenhum tipo de tratamento ortodôntico anteriormente e que os irmãos gêmeos apresentassem documentação realizada na mesma data e em condições técnicas idênticas. Após a realização do cefalograma e marcação dos pontos cefalométricos, empregando o software Dentofacial Planner Plus, 16 dimensões foram obtidas, sendo 9 lineares e 7 angulares. No tratamento estatístico dos dados obtidos, utilizaram-se os testes t-student para amostras independentes, média do módulo da diferença, desvios-padrão e intervalo de confiança em cada par e em cada variável para verificar a magnitude de cada variação. Por meio da metodologia empregada nesta pesquisa, foi possível verificar que o complexo craniofacial apresenta um controle genético extremamente forte para todas as variáveis estudadas. Foi detectada menor variação nos parâmetros verticais, quando avaliados por dimensões angulares, em relação aos parâmetros horizontais. O comportamento dos parâmetros anterior e posterior apresentou extrema similaridade. Os parâmetros angulares e lineares apresentaram comportamentos semelhantes. O parâmetro superior da face é o elemento mais estável do complexo craniofacial, com uma variabilidade correspondente à metade do parâmetro inferior

Efeitos genéticos e do envolvimento dos níveis de actividade física e aptidão física associada à saúde: um estudo em gémeos dos 6 aos 12 anos de idade do Arquipélago dos Açores (Portugal) / Genetic and environmental effects in physical activity and health related physical fitness. A study in twins aged 6-to-12 years of the Azores Islands (Portugal)

Este trabalho pretende estimar a importância de factores genéticos e do envolvimento nos níveis de actividade física (ActF) e aptidão física associados à saúde (ApFS) em crianças. Os dados provêm de 96 pares de gêmeos monozigóticos e dizigóticos do arquipélago dos Açores (Portugal) cuja idade varia entre os 6 e os 12 anos. A ActF foi estimada com base no questionário de Godin e Shephard e a ApFS foi avaliada a partir da bateria de testes Prudential Fitnessgram. O cálculo das estimativas da influência genética e do envolvimento comum e único foi efectuado com base em procedimentos bem referenciados na literatura. Os resultados sugerem que cerca de 25% das diferenças interindividuais nos níveis de ActF podem ser atribuídas a efeitos genéticos. Já os valores de ApFS evidenciam um maior contributo génico: 32% na prova do trunk lift, 53.4% na prova de push-up, 38.4% na prova de curl-up, 58.2% na corrida-marcha da milha e 88% no índice de massa corporal. Em conclusão pode referir-se que os efeitos genéticos que governam as diferenças interindividuais são de magnitude baixa a moderada, exceptuando o índice de massa corporal. De particular importância é o efeito do envolvimento comum. Este último dado deve ser considerado de modo importante no sentido de consolidar a relevância da família, sobretudo dos progenitores na promoção de um estilo de vida activo e saudável.

The purposes of this study were to estimate the importance of genetic and environmental factors in physical activity (ActF) and health-related physical fitness (ApFS) levels of children. Data comes from 96 twin monozygotic and dizygotic pairs aged 6-to-12 years of the Azores Islands (Portugal). Physical activity was estimated with the Godin & Shephard questionnaire, and the ApFS was evaluated with the Prudential Fitnessgram test battery. Genetic factors, common and unique environmental estimates were calculated with well-known formulas. About 25% of the total variance in ActF was explained by genetic differences among subjects. In ApFS genetic effects were of the following magnitude: 32% for curl-up, 53.4% for trunk-lift, 38.4% for curl-up, 58.2% for 1 mile run-walk, and 88% for body mass index. In conclusion we may state that the magnitude of genetic effects are low to moderate, with exception of body mass index. An emphasis must be stated for the importance of common environmental effects. This fact should be regarded as an issue to pinpoint the importance of familial environment, especially the relevance of parents in their promotion of active and healthy lifestyles among family members.

Aspectos genéticos da actividade física e aptidão física associada à saúde. Estudo em gêmeos dos 12 aos 40 anos de idade do arquipélago dos Açores (Portugal) / Genetic aspects of physical activity and health related physical fitness. A study in twins aged 12-to-40 years from the Azores (Portugal) islands

Este estudo tem como propósitos estudar aspectos da variação genética nos níveis de actividade física e aptidão física associada à saúde de gémeos do arquipélago dos Açores (Portugal). Com base numa amostra de 64 pares de gémeos dos 12 aos 40 anos pertencentes às 8 das 9 ilhas, foramavaliados (1) os níveis de actividade física com base no questionário de Baecke, (2) e os valores da aptidão física referenciados pela saúde providenciados pela bateria Fitnessgram. Os procedimentosestatísticos utilizados foram os usuais neste tipo de análises, bem como foram calculadas as estimativas de heritabilidade (h2). Todos os cálculos foram efectuados nos programas SPSS 10 e Systat 10. Os resultados mostraram estimativas de h2 moderadas a elevadas para os níveis de actividade física, entre 23.4% e 77%. Um quadro algo semelhante de resultados ocorreu para os diferentes testes marcadores da aptidão física - entre 30% e 80%. As conclusões remetem-nos para diferenças genéticas moderadas a elevadas entre sujeitos e que são responsáveis pela heterogeneidade nos valores de actividade física e aptidão física. Contudo, é também aberta uma porta à influência ambiental nos programas deeducação física e desportiva, para além de outros elementos.

This study aims at the investigation of the genetic variance in the levels of physical activity and health related physical fitness of twins for the archipelago of Azores (Portugal). Based on a sample of 64 twin pairs aged 12 to 40 years from 8 of the 9 islands, we evaluated (1) their levels of physical activity based in the Baecke questionnaire, as well as (2) their health related physical fitness values, as provided by the Fitnessgram test battery. Standard statistical procedures were used in these types of analysis, aswell as heritabilities estimates (h2). All computations were done in SPSS 10 and SYSTAT 10. Results showed moderate to high h2 estimates for physical activity, between 23.4% and 77%. A similar picture was observed in the marker test for physical fitness - between 30% and 80%. We may conclude that moderate to high genetic differences among subjects are responsable for the heterogeneity of observed values in physical activity and physical fitness. It should also be mentioned that environmental factorsare also important, opening an important window for the physical and sportive education, as well as for other environmental factors.