El embarazo gemelar monocorial desde la perspectiva de la teoría de la complejidad / Monochorionic twin pregnancy from the perspective of the theory of complexity

En la práctica, es muy frecuente asociar las gestaciones gemelares monocoriales (MC) con embarazos complejos o complicados, utilizando ambos términos en forma intercambiable. Sin embargo, no lo son; el dinamismo es protagonista en los sistemas complejos, pero no en los complicados. Para entender a la embarazada con una gestación MC como un sistema complejo, primero se desarrollarán las características principales de los embarazos MC; su placenta es una de las principales responsables de los problemas. Luego se analizará el embarazo MC desde la complejidad, identificando las características del sistema y sus complicaciones como propiedades emergentes.

In practice, it is very common to associate monochorionic (MC) twin pregnancies with complex or complicated pregnancies, using both terms interchangeably. However, these are not synonyms; dynamism is the protagonist in complex systems, but not in complicated ones. In order to understand a MC pregnancy as a complex system, it is necessary to first look into its main characteristics. The placenta is one of the main sources of problems. Then, the MC pregnancy has to be analyzed from the perspective of complexity, identifying the system characteristics and its complications as emergent properties.

A descriptive analysis on hypertension in adult twins in China / 中华流行病学杂志

Objective: To describe the distribution characteristics of hypertension among adult twins in the Chinese National Twin Registry (CNTR) and to provide clues for exploring the role of genetic and environmental factors on hypertension. Methods: A total of 69 220 (34 610 pairs) of twins aged 18 and above with hypertension information were selected from CNTR registered from 2010 to 2018. Random effect models were used to describe the population and regional distribution of hypertension in twins. To estimate the heritability, the concordance rates of hypertension were calculated and compared between monozygotic twins (MZ) and dizygotic twins (DZ). Results: The age of all participants was (34.1±12.4) years. The overall self-reported prevalence of hypertension was 3.8%(2 610/69 220). Twin pairs who were older, living in urban areas, married, overweight or obese, current smokers or ex-smokers, and current drinkers or abstainers had a higher self-reported prevalence of hypertension (P<0.05). Analysis within the same-sex twin pairs found that the concordance rate of hypertension was 43.2% in MZ and 27.0% in DZ, and the difference was statistically significant (P<0.001). The heritability of hypertension was 22.1% (95%CI: 16.3%- 28.0%). Stratified by gender, age, and region, the concordance rate of hypertension in MZ was still higher than that in DZ. The heritability of hypertension was higher in female participants. Conclusions: There were differences in the distribution of hypertension among twins with different demographic and regional characteristics. It is indicated that genetic factors play a crucial role in hypertension in different genders, ages, and regions, while the magnitude of genetic effects may vary.

A descriptive analysis of hyperlipidemia in adult twins in China / 中华流行病学杂志

Objective: To describe the distribution characteristics of hyperlipidemia in adult twins in the Chinese National Twin Registry (CNTR) and explore the effect of genetic and environmental factors on hyperlipidemia. Methods: Twins recruited from the CNTR in 11 project areas across China were included in the study. A total of 69 130 (34 565 pairs) of adult twins with complete information on hyperlipidemia were selected for analysis. The random effect model was used to characterize the population and regional distribution of hyperlipidemia among twins. The concordance rates of hyperlipidemia were calculated in monozygotic twins (MZ) and dizygotic twins (DZ), respectively, to estimate the heritability. Results: The age of all participants was (34.2±12.4) years. This study's prevalence of hyperlipidemia was 1.3% (895/69 130). Twin pairs who were men, older, living in urban areas, married,had junior college degree or above, overweight, obese, insufficient physical activity, current smokers, ex-smokers, current drinkers, and ex-drinkers had a higher prevalence of hyperlipidemia (P<0.05). In within-pair analysis, the concordance rate of hyperlipidemia was 29.1% (118/405) in MZ and 18.1% (57/315) in DZ, and the difference was statistically significant (P<0.05). Stratified by gender, age, and region, the concordance rate of hyperlipidemia in MZ was still higher than that in DZ. Further, in within-same-sex twin pair analyses, the heritability of hyperlipidemia was 13.04% (95%CI: 2.61%-23.47%) in the northern group and 18.59% (95%CI: 4.43%-32.74%) in the female group, respectively. Conclusions: Adult twins were included in this study and were found to have a lower prevalence of hyperlipidemia than in the general population study, with population and regional differences. Genetic factors influence hyperlipidemia, but the genetic effect may vary with gender and area.

A case-control study on the association between a healthy lifestyle and obesity among adult twins in Shanghai / 中华流行病学杂志

Objective: To investigate the associations between the numbers of healthy lifestyles and overweight/obesity and abdominal obesity in adult twins in Shanghai. Methods: Based on the Shanghai Twin Registry System Phase Ⅱ survey data in 2017-2018, a case-control study was conducted to analyze the association between healthy lifestyles and obesity and further adjusted for confounders by a co-twin control study. Results: A total of 7 864 adult twins (3 932 pairs) were included. In the co-twin case-control analysis for monozygotic twins, compared with participants with 0 to 2 healthy lifestyles, those with 3 and 4 to 5 healthy lifestyles had a 49% (OR=0.51, 95%CI: 0.28-0.93) and 70% (OR=0.30, 95%CI: 0.13-0.69) lower risk of overweight/obesity, respectively, and a 17% (OR=0.83, 95%CI: 0.44-1.57) and 66% (OR=0.34, 95%CI: 0.14-0.80) lower risk of abdominal obesity, respectively. For each additional healthy lifestyle, the risk of developing overweight/obesity was reduced by 41% (OR=0.59, 95%CI: 0.42-0.85), and the risk of developing abdominal obesity was reduced by 37% (OR=0.63, 95%CI: 0.44-0.90). Conclusion: An increasing number of healthy lifestyles was associated with a marked decreased risk for both overweight/obesity and abdominal obesity.

Analysis of typing conversion and perinatal outcomes in twins with selective intrauterine growth restriction of different subtypes / 中华妇产科杂志

Objective: To retrospectively analyze the clinical data of different types of selective intrauterine growth restriction (sIUGR) pregnant women under expectant management, including the natural evolution, typing conversion and perinatal outcomes. Methods: The clinical data of 153 pregnant women with sIUGR under expected treatment in Women's Hospital, Zhejiang University School of Medicine from January 2014 to December 2018 were collected. Maternal characteristics including maternal age, gravidity, parity, method of conception, pregnancy complication, gestational age at delivery, indication for delivery, birth weight, the rate of intrauterine and neonatal death and neonatal outcomes were recorded. Pregnant women with sIUGR were divided into three types according to end-diastolic umbilical artery flow Doppler ultrasonography, and the differences of typing conversion and perinatal outcomes of sIUGR pregnant women based on the first diagnosis were compared. Results: (1) Clinical characteristics and pregnancy outcomes: among 153 pregnant women with sIUGR, 100 cases (65.3%) were diagnosed with type Ⅰ, 35 cases (22.9%) with type Ⅱ, and 18 cases (11.8%) with type Ⅲ. There were no significant differences in age, conception mode, pregnancy complications, first diagnosis gestational age, characteristics of umbilical cord insertion, delivery indications, fetal intrauterine mortality and neonatal mortality among three types of sIUGR pregnant women (all P>0.05). The average gestational age at delivery of type Ⅰ sIUGR was (33.5±1.9) weeks, which was significantly later than those of type Ⅱ and Ⅲ [(31.3±1.8), (31.2±1.1) weeks, P<0.001]. The percentage disordance in estimated fetal weight (EFW) of type Ⅰ sIUGR was significantly lower than those of type Ⅱ and type Ⅲ (P<0.001). The incidence rate of neonatal intensive care unit (NICU) admission, cerebral leukomalacia and respiratory complications of both fetus and necrotizing enterocolitis of large fetus in type Ⅰ were significantly lower than those in type Ⅱ and type Ⅲ (all P<0.05). (2) Typing conversion: in 100 cases of type Ⅰ sIUGR, 18 cases progressed to type Ⅱ and 10 cases progressed to type Ⅲ. Compared with 72 stable type Ⅰ sIUGR, those with progressed type Ⅰ sIUGR had higher incidence of NICU admission and lung disease in both fetuses, and cerebral leukomalacia and necrotizing enterocolitis in large fetus (all P<0.05). The proportion of inconsistent cord insertion was significantly higher in those type Ⅰ progressed to type Ⅲ (6/10) than in those with stable type Ⅰ (19.4%, 14/72) and type Ⅰ progressed to type Ⅱ sIUGR [0 (0/18), P=0.001]. Four cases of type Ⅱ sIUGR reversed to type Ⅰ and 6 cases reversed to type Ⅲ. Compared with type Ⅱ reversed to type Ⅰ sIUGR, those stable type Ⅱ and type Ⅱ reversed to type Ⅲ sIUGR had a higher incidence of NICU admission in large fetus (P<0.05). Two cases of type Ⅲ sIUGR reversed to type Ⅰ and 6 cases progressed to type Ⅱ. There were no significant differences in fetal serious complications in type Ⅲ sIUGR with or without doppler changes (all P>0.05). Conclusions: The different types of sIUGR could convert to each other. The frequency of ultrasound examinations should be increased for patients with the type Ⅰ sIUGR, especially when the percentage discordance in EFW is substantial or with discordant cord insersion.

Clinical analysis of monochorionic-diamniotic twins with genetic discordance / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology of 5 cases of monochorionic-diamniotic (MCDA) with genetic discordance.@*METHODS@#148 cases of MCDA twins who were diagnosed by amniocentesis at the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region from January 2016 to June 2020 were selected as the study subjects. Relevant clinical data of the pregnant women were collected, and amniotic fluid samples of the twins were collected separately. Chromosomal karyotyping analysis and single nucleotide polymorphism array (SNP array) assay were carried out.@*RESULTS@#The results of chromosomal karyotyping analysis showed that 5 of the MCDA twins had inconsistent chromosome karyotypes, with an incidence of 3.4% (5/148). SNP array assay showed that 3 fetuses were mosaics.@*CONCLUSION@#Genetic discordance occurs among MCDA twins, and prenatal counseling for such cases should be given by doctors with experience in medical genetics and fetal medicine, and personalized clinical management should be recommended.

Dental arch characteristics among South Indian twins - A morphometric study

Genetic and environmental factors are essential in occlusal variations and malocclusion and have been of considerable interest to orthodontists. Studies on twin pairs are one of the most effective methods for investigating genetically determined occlusal variables. Many studies have focused on distances between first molars or between canines but malocclusions can also occur in other regions of the dental arch. Aim: To evaluate the characteristics of the dental arch between pairs of Monozygotic (MZ) and Dizygotic (DZ) twins from Southern India. Methods: A random sample of 51 twin pairs (12­18years old) participated in this study. The zygosity of twin pairs was recorded by facial appearance. The occlusion of the first permanent molars was recorded according to Angle's classification. Study models were prepared to assess dental arch characteristics (i.e., arch form, arch perimeter, arch length; intercanine, intermolar width, and teeth size discrepancy). The obtained data was statistically analyzed using SPSS software 19.0. The student's t-test (two-tailed, independent) and Chi-square test was used to determine the significance of studied parameters. Results: Angle's Class I molar relation was more commonly observed followed by the Class II molar relationship among twins. The measured dental arch dimensions did not show a statistically significant difference among twin pairs. The ovoid arch form was commonly observed among Monozygotic and Dizygotic Twins. There was a similarity among MZ and DZ twins in the anterior and overall Bolton's ratio. Conclusion: There were similar occurrences of measured parameters among twins, which showed genetic predominance in the expression of measured dental arch traits

A descriptive analysis on type 2 diabetes in twins in China / 中华流行病学杂志

Objective: To describe the distribution characteristics of type 2 diabetes in twins in Chinese National Twin Registry (CNTR), provide clues and evidence for revealing the influence of genetic and environmental factors for type 2 diabetes. Methods: Of all twins registered in the CNTR during 2010-2018, a total 18 855 twin pairs aged ≥30 years with complete registration information were included in the analysis. The random effect model was used to describe the population and area distribution characteristics and concordance of type 2 diabetes in twin pairs. Results: The mean age of the subjects was (42.8±10.2) years, the study subjects included 10 339 monozygotic (MZ) twin pairs and 8 516 dizygotic (DZ) twin pairs. The self-reported prevalence rate of type 2 diabetes was 2.2% in total population and there was no sighificant difference between MZ and DZ. Intra-twin pairs analysis showed that the concordance rate of type 2 diabetes was 38.2% in MZ twin pairs, and 16.0% in DZ twin pairs, the difference was statistically significant (P<0.001). The concordance rate of type 2 diabetes in MZ twin parts was higher than that in DZ twin pairs in both men and women, in different age groups and in different areas (P<0.05). Further stratified analysis showed that in northern China, only MZ twin pairs less than 60 years old were found to have a higher concordance rate of type 2 diabetes compared with DZ twin pairs (P<0.05). In southern China, the co-prevalence rate in male MZ twin pairs aged ≥60 years was still higher than that in DZ twin pairs (P<0.05). Conclusion: The twin pairs in this study had a lower self-reported prevalence of type 2 diabetes than the general population. The study results suggested that genetic factors play a role in type 2 diabetes prevalence in both men and women, in different age groups and in different areas, however, the effect might vary.

A descriptive analysis on coronary heart disease in adult twins in China / 中华流行病学杂志

Objective: To describe the distribution characteristics of coronary heart disease in adult twins recruited from Chinese Twin Registry (CNTR), and provide clues and evidence for the effect of genetic and environmental influences on coronary heart disease. Methods: By using the data of CNTR during 2010-2018, a total of 34 583 twin pairs aged ≥18 years who completed questionnaire survey and had related information were included in the current study to analyze the population and area distribution characteristics of coronary heart disease. Random effect models were used to compare the differences between groups. The concordane rate of coronary heart disease were calculated respectively in monozygotic (MZ) twin pairs and dizygotic (DZ) twin pairs to estimate the heritability. Results: The twin pairs included in this analysis were aged (34.2±12.4) years. The overall prevalence rate of coronary heart disease in twin pairs was 0.7%. Twin pairs who were women, older, obese and lived in northern China had higher prevalence of coronary heart disease (P<0.05). Intra-pair analysis in the same-sex twin pairs found that the concordane rate of coronary heart disease was higher in MZ twin pairs (25.3%) than in DZ twins (7.4%), and the difference was statistically significant (P<0.001). The overall heritability of coronary heart disease was 19.3% (95%CI: 11.8%-26.8%). Stratified by gender, age and area, the concordane rate was still higher in MZ twin pairs than in DZ pairs. Participants who were women, aged 18-30 years or ≥60 years and lived in northern China had a higher heritability of coronary heart disease. Conclusion: The distribution of coronary heart disease in twin pairs differed in populations and areas. The prevalence of coronary heart disease was affected by genetic factors, but the effect varied with age, gender and area.

Gene-lifestyle interaction on coronary heart disease in adult twins of China / 中华流行病学杂志

Objective: To explore the gene-lifestyle interaction on coronary heart disease (CHD) in adult twins of China. Methods: Participants were selected from twin pairs registered in the Chinese National Twin Registry (CNTR). Univariate interaction model was used to estimate the interaction, via exploring the moderation effect of lifestyle on the genetic variance of CHD. Results: A total of 20 477 same-sex twin pairs aged ≥25 years were recruited, including 395 CHD cases, and 66 twin pairs both had CHD. After adjustment for age and sex, no moderation effects of lifestyles, including current smoking, current drinking, physical activity, intake of vegetable and fruit, on the genetic variance of CHD were found (P>0.05), suggesting no significant interactions. Conclusion: There was no evidence suggesting statistically significant gene-lifestyle interaction on CHD in adult twins of China.

La ética profesional, entre la tiranía del saber y el campo normativo. De lo idéntico a lo desconocido / Professional Ethics, between the tyranny of knowledge and the normative fieldf.From the identical to the unknown

El reciente lanzamiento en Argentina del documental Tres idénticos desconocidos (Wardle, 2018) nos permite problematizar uno de los experimentos más atroces de la historia de la psicología en los Estados Unidos. Para dilucidar la incidencia de distintos modos de crianza en gemelos con idéntica estructura genética, el psiquiatra Peter Neubauer y su colega Viola Bernard condujeron durante años una oscura investigación, desatendiendo una serie de objeciones éticas en la experimentación con seres humanos, y demostrando así la disyunción entre el campo normativo y ciertos discursos científicos comandados por la exigencia insensata del todo saber, especialmente cuando la valoración ética de las prácticas profesionales queda únicamente supeditada a un análisis posterior de sus efectos.

The recent release of the documentary Three Identical Strangers (Wardle, 2018) in Argentina allows us to problematize one of the most atrocious experiments in the history of North American psychology. To elucidate the incidence of different nurturing in twins with identical genetic structure, the psychiatrist Peter Neubauer and his colleague Viola Bernard conducted an obscure investigation for years, disregarding a series of ethical objections in the experimentation with human beings, and demonstrating the disjunction between the normative field and certain scientific discourses commanded by the insane demand of all knowledge, especially when the ethical evaluation of professional practices is only subject to a subsequent analysis of their effects.

Implication of epigenetic factors in the pathogenesis of type 1 diabetes / 中华医学杂志(英文版)

Type 1 diabetes (T1D) is an autoimmune disease that resulted from the severe destruction of the insulin-producing β cells in the pancreases of individuals with a genetic predisposition. Genome-wide studies have identified HLA and other risk genes associated with T1D susceptibility in humans. However, evidence obtained from the incomplete concordance of diabetes incidence among monozygotic twins suggests that environmental factors also play critical roles in T1D pathogenesis. Epigenetics is a rapidly growing field that serves as a bridge to link T1D risk genes and environmental exposures, thereby modulating the expression of critical genes relevant to T1D development beyond the changes of DNA sequences. Indeed, there is compelling evidence that epigenetic changes induced by environmental insults are implicated in T1D pathogenesis. Herein, we sought to summarize the recent progress in terms of epigenetic mechanisms in T1D initiation and progression, and discuss their potential as biomarkers and therapeutic targets in the T1D setting.

Fetus in fetu: caso clínico estudiado con tomografía tridimensional / Fetus in Fetu: clinical case studied with three-dimensional tomography

Antecedentes: Fetus in fetu (FIF) es una rara anomalía congénita de gemelos monocigotos asimétricos, donde el gemelo parásito se desarrolla anormalmente dentro del cuerpo del gemelo huésped. Actualmente hay menos de 200 casos reportados a nivel mundial siendo este el segundo caso en Honduras. Caso clínico: Se reporta el caso de un paciente masculino, recién nacido a término en la sala de maternidad del Hospital San Felipe, quien a su nacimiento se observó distensión abdominal, hernia umbilical, hernia inguino-escrotal izquierda y tumoración en el hipocondrio izquierdo por lo que se decide realizar una radiografía anteroposterior toracoabdominal revelado un tumor en la región izquierda del abdomen con presencia de calcificaciones. Se refiriere al Hospital Escuela Universitario donde se le efectuó un ultrasonido abdominal total con reporte de masa heterogénea de 5 cm3 de volumen con componente cálcico en su interior, que tuvo que ser correlacionada con tomografía axial computarizada con reconstrucción 3D dando como resultado masa heterogenia con huesos axiales y apendiculares en su interior compatible con FIF. Se realizó intervención quirúrgica con resección de tumoración retroperitoneal y sus anexos sin secuelas ni complicaciones por lo cual se da alta médica. Conclusión: Aunque el FIF es una enfermedad muy rara, el tratamiento de elección será la resección de la masa y su pronóstico es favorable cuando la masa se ubica en el área retroperitoneal. Se puede observar que la tomografía tridimensional es una técnica de imagen útil para la diferenciación entre un FIF y un teratoma en el diagnóstico preoperatorio...(AU)

Twin-twin transfusion syndrome - a University Hospital experience with intrauterine treatment / Síndrome da transfusão feto-fetal - experiência de um hospital universitário com tratamento intrauterino

ABSTRACT Introduction: twin-to-twin transfusion syndrome (TTTS), defined by combination of polyhydramnios-oligohydramnios, is the most prevalent (5%-35%) of the abnormalities due to placental vascular anastomoses and the most lethal (80%-100% mortality) if untreated. Fetoscopic laser ablation of abnormal vasculature using the Solomon technique is the gold standard approach. It consists of interrupting the intertwin blood flow. Objectives: to present our initial experience at the Fetal Surgery Service of the Hospital de Clinicas of the Federal University of Parana (HC-UFPR) and to compare our results with those reported in the literature. Methods: we conducted a retrospective analysis of pregnancies who had undergone laser ablation, assessing data on Quintero's staging, gestational age at diagnosis and at the time of the procedure, placental position, immediate post-procedure survival, and survival after the neonatal period. We then compared these data with the most recent data available in the literature. Results: we analyzed ten TTTS cases. The diagnosis was performed before the 26th week of pregnancy (median 20.8 weeks) and treatment occurred in a median of 9.5 days later. The distribution by the Quintero's staging was of three cases in stage II, five in stage III, and two in stage IV. In 50% of the gestations, at least one of the fetuses survived through the neonatal period. Conclusion: the treatment of TTTS in the HC-UFPR had a positive impact in the survival of the affected fetuses, although the results were worse than the ones reported in the literature, probably due to the delay in referencing the patients to our service, leading to a prolonged interval between diagnosis and treatment.

RESUMO Introdução: a síndrome de transfusão feto-fetal (STFF), definida pela combinação polidrâmnio-oligohidrâmnio, é a mais prevalente (5 a 35%) das anormalidades associadas às anastomoses vasculares placentárias e tem a maior letalidade (80 a 100%) se não tratada. A ablação a laser destes vasos por via fetoscópica com a técnica de Solomon é o tratamento de escolha atual para a interrupção das anastomoses vasculares. Objetivo: apresentar a experiência inicial do Serviço de Cirurgia Fetal do Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR) e comparar nossos resultados com os da literatura. Métodos: foram revisados os prontuários de todas as pacientes submetidas ao procedimento de ablação a laser, sendo analisados os dados referentes ao estadiamento de Quintero, à idade gestacional ao diagnóstico e ao procedimento, à posição placentária, à sobrevida imediata pós-procedimento e sobrevida após o período neonatal. Os dados foram então comparados com os mais recentes disponíveis na literatura. Resultados: dez casos de STFF foram analisados. Todos diagnosticados antes da 26a semana (mediana 20,79) e o intervalo diagnóstico-tratamento teve mediana de 9,5 dias. A distribuição pelo estadiamento de Quintero foi: três casos no estádio II, cinco casos no III e dois casos no IV. Em 50% das gestações pelo menos um dos fetos sobreviveu ao período neonatal. Conclusão: o tratamento da STFF no HC-UFPR impactou positivamente a sobrevida dos fetos acometidos. Entretanto, nossos resultados estão aquém dos reportados na literatura, possivelmente pelo demora no referenciamento das pacientes, com intervalo aumentado entre diagnóstico e tratamento.

Neutropenia aloimune neonatal em gêmeas idênticas / Neonatal alloimmune neutropenia in identical twins

A neutropenia aloimune neonatal (NAN) é uma patologia causada pelo antagonismo imunológico, como a doença hemolítica do recém-nascido ou a trombocitopenia aloimune neonatal, mas relacionada aos neutrófilos, em vez de glóbulos vermelhos ou plaquetas. Descreveremos um caso clínico de duas gêmeas idênticas nascidas a termo, com Apgar de 8 e 9, sendo que após algumas horas do nascimento apresentaram febre. Um exame de sangue revelou neutropenia grave que resultou em sepse. O diagnóstico da NAN foi realizado clinicamente e por testes de histocompatibilidade. A prova cruzada por citometria de fluxo foi positiva, usando soro da mãe e suspensões celulares (granulócitos e linfócitos) das gêmeas e do pai. Este teste não fornece informações sobre para qual sistema genético os anticorpos foram positivos, se contra os antígenos específicos de neutrófilos humanos (HNA) ou contra os antígenos leucocitários humanos (HLA). Para o esclarecimento, realizamos o teste de aglutinação de granulócitos (GAT) com um painel de doadores fidelizados e com antígenos HNA1-5 conhecidos, utilizando o soro materno como reagente. Foi também realizada a pesquisa de anticorpos anti-HLA e anti-HNA no soro materno. Os genótipos HLA e HNA foram identificados, permitindo conhecer as especificidades dos anticorpos maternos contra os antígenos dos neutrófilos do marido e das filhas. O diagnóstico de NAN não é realizado na maioria dos hospitais de nosso país e do exterior, devido à dificuldade de execução dos testes de histocompatibilidade, no entanto a prova cruzada por citometria de fluxo pode facilmente ser implantada nos laboratórios clínicos, sendo que está descrita detalhadamente nesse caso clínico.

Neonatal alloimmune neutropenia (NAN) is a disease caused by immunological antagonism, such as hemolytic disease of the newborn or neonatal alloimmune thrombocytopenia, but related to neutrophils rather than to red blood cells or platelets. We will describe a clinical case of two identical twins born with Apgar 8 and 9 that started with fever few hours after delivery. A blood test revealed severe neutropenia, which was followed by sepsis. The diagnosis of NAN was done clinically and by histocompatibility testing. Flow cytometry crossmatch was positive, using mother serum and cell suspensions (granulocytes and lymphocytes) from the twin girls and from the father. This test did not provide information about the genetic system for which the antibodies are positive, if against human neutrophil antigens (HNA) or human leucocyte antigens (HLA). To clear this, the granulocyte agglutination test (GAT) was performed with a panel of control donors with known HNA1-5 antigens, using the maternal serum as a reagent. We did also a Luminex screening assay for detection of anti-HLA and anti-HNA antibodies in the mother serum. The HLA and HNA genotypes were identified, which allowed to define specificities in mother's antibodies against the neutrophil surface antigens from her husband and from the twins. The diagnosis of NAN diagnose is not done in most hospitals worldwide, mainly by the difficulty in executing the histocompatibility test. However, the crossmatch by flow cytometry could be easily done in clinical laboratories following the method described in this article.

Mirror image: an unusual case of prolonged tooth retention in twins

Introduction: Studies of twins are important because environmental and genetic factors seem to be related to the phenotypic alterations. Objective: This paper presents a unique case of monozygotic twins with mirror image of a retained primary central incisor. Case report: Twin male brothers, 9-years-old, presented prolonged retention of the primary central upper incisor. The over-retained teeth in one twin were a mirror image of those in the other twin. The first twin presented a prolonged retention of the tooth 51 whereas the other twin presented a prolonged retention of tooth 61. After radiographic exams the over-retained teeth were extracted. Conclusion: Twins may show similarity in pattern of dental anomalies supporting the influence of genetic factors. In identical twins the location of diagnosed anomalies can be mirror imaged. This fact should lead the professional to examine the pair of twins in order to diagnose any dental anomaly that may be present.

Introdução: Estudos feitos em gêmeos são importantes porque fatores ambientais e genéticos parecem estar relacionados às alterações fenotípicas. Objetivo: Este artigo apresenta um caso raro de gêmeos monozigóticos apresentando imagem em espelho de retenção prolongada de incisivos centrais decíduos superiores homólogos. Relato do caso: Os irmãos gêmeos, com 9 anos de idade, não apresentavam história de trauma orofacial ou doença comum da infância. Após exames clínicos e radiográficos foram identificados a retenção do dente 51 no gêmeo 1 e do dente 61 no gêmeo 2. Em ambos os pacientes, os dentes 11 e o 21 estavam em erupção. O tratamento proposto foi a exodontia dos dentes decíduos com anestesia local e acompanhamento. Conclusão: Gêmeos podem apresentar semelhança no padrão de anomalias dentárias devido à influência de fatores genéticos. Adicionalmente, em gêmeos monozigóticos, a localização das anomalias diagnosticadas pode se apresentar invertidas ou imagem em espelho. Esse fato deve estimular o profissional a examinar o par de gêmeos para diagnosticar qualquer anomalia dentária que possa estar presente. O diagnóstico precoce e tratamento adequados devem ser realizados para evitar danos funcionais e estéticos em pacientes com retenções dentárias.

Correlation between fasting plasma glucose, HbA1c and DNA methylation in adult twins / 北京大学学报(医学版)

OBJECTIVE@#To explore the cytidine-phosphate-guanosine (CPG) sites associated with fas-ting plasma glucose (FPG) and glycated haemoglobin (HbA1c) in twins.@*METHODS@#In the study, 169 pairs of monozygotic twins were recruited in Qingdao, Zhejiang, Jiangsu, Sichuan and Heilongjiang in June to December of 2013 and June 2017 to October 2018. The methylation was detected by Illumina Infinium HumanMethylation450 BeadChip and Illumina Infinium MethylationEPIC BeadChip. According to the Linear Mixed Effect model (LME model), fasting plasma glucose and HbA1c were taken as the main effects, the methylation level (β value) was taken as the dependent variable, continuous variables, such as age, body mass index (BMI), blood pressure, components of blood cells, surrogate variables generated by SVA, and categorical variables, such as gender, smoking and drinking status, hypoglycemic drugs taking, were included in the fixed effect model as covariates, and the identity numbers (ID) of the twins was included in the random effect model. The intercept was set as a random. Regression analysis was carried out to find out the CpG sites related to fasting blood glucose or HbA1c, respectively.@*RESULTS@#In this study, 338 monozygotic twins (169 pairs) were included, with 412 459 CpG loci. Among them, 114 pairs were male, and 55 pairs were female, with an average age of (48.2±11.9) years. After adjustment of age, gender, BMI, blood pressure, smoking, drinking, blood cell composition, and other covariates, and multiple comparison test, 7 CpG sites (cg19693031, cg01538969, cg08501915, cg04816311, ch.8.1820050F, cg06721411, cg26608667) were found related to fasting blood glucose, 3 of which (cg08501915, ch.8.1820050f, cg26608667) were the newly found sites in this study; whereas 10 CpG sites (cg19693031, cg04816311, cg01538969, cg01339781, cg01676795, cg24667115, cg09029192, cg20697417, ch.4.1528651F, cg16097041) were found related to HbA1c, and 4 of which(cg01339781, cg24667115, cg20697417, and ch.4.1528651f) were new. We found that cg19693031 in TXNIP gene was the lowest P-value site in the association analysis between DNA methylation and fas-ting plasma glucose and HbA1c (PFPG=2.42×10-19, FDRFPG<0.001; PHbA1c=1.72×10-19, FDRHbA1c<0.001).@*CONCLUSION@#In this twin study, we found new CpG sites related to fasting blood glucose and HbA1c, and provided some clues that partly revealed the potential mechanism of blood glucose metabolism in terms of DNA methylation, but it needed further verification in external larger samples.

Poder discriminatório de medidas faciais fotoantropométricas / Discriminatory power of photo-anthropometric facial measures

Distinguir indivíduos por sua aparência facial é uma tarefa desafiadora para as ciências forenses, particularmente nos exames de Identificação Facial Forense (FFI). A fim de fundamentar conclusões nesses casos, esta tese tem como objetivo avaliar a freqüência e o poder discriminatório de medidas faciais fotoantropométricas obtidas de indivíduos não relacionados e de gêmeos idênticos (monozigóticos, univitelinos ou MZT). Para tanto, esta tese foi estruturada na forma de três capítulos. O primeiro capítulo tem como objetivo avaliar a frequência de 211 distâncias Euclidianas (ED) na população brasileira, de ambos os sexos e de grupos etários distintos (20, 30, 40, 50 e acima de 60 anos), utilizando uma metodologia métrica de avaliação das estruturas faciais em imagens frontais bidimensionais (2D) (fotoantropometria facial - FPA). No intuito de selecionar medidas com maior potencial de discriminação, um método de regressão logística foi aplicado assim como a avaliação de erro interexaminadores. De forma geral, potencial discriminatório foi observado para 16 EDs. Essas medidas foram utilizadas para o estabelecimento de 20 índices (IN) e 21 ângulos (AN) faciais e seu poder discriminatório foi verificado no segundo estudo por meio da análise de 920 imagens de indivíduos de ambos os sexos e de oito faixas etárias distintas (5, 15, 20, 30, 40, 50, 60 e acima de 70 anos de idade). A análise consistiu em achar valores duplicados considerando três fontes de variabilidade: interindivíduo (ER), intraindivíduo (RA) quando analisado pelo mesmo examinador (RAA), e intraindivíduo quando analisado por diferentes examinadores (RAE). Como resultado, pode-se observar que 15 ED ou 20 IN foram necessários para alcançar uma probabilidade de menos de um indivíduo com medidas duplicadas em uma população de um milhão (106). A mesma probabilidade foi alcançada quando 18 ANs foram utilizados somente nas idades de 5, 15, 50, 60 e 70 anos. O último capítulo consistiu em avaliar a capacidade dessas medidas em distinguir um grupo populacional cujas características faciais são extremamente similares, ou seja, MZT. Para isso, análise de duplicadas foram realizadas entre e dentre pares de MZT considerando intervalos de confiança intraindivíduo. Como resultado, pode-se observar padrões diferentes de discriminação das medidas faciais quando MZT foram comparados com indivíduos não correlatos. Podendo-se concluir que medidas faciais fotoantropométricas são capazes de discriminar indivíduos, inclusive MZT.

Desfecho perinatal no crescimento intrauterino restrito seletivo em gestações gemelares monocoriônicas acompanhadas de forma expectante / Perinatal outcome in selective intrauterine growth restriction in monochorionic twin pregnancies followed expectantly

Objetivo: Avaliar a morbimortalidade perinatal de gestações gemelares monocoriônicas afetadas por Crescimento Intrauterino Restrito Seletivo (CIUR-s), de acordo com o padrão de fluxo ao Doppler na artéria umbilical do gêmeo menor. Métodos: Esse estudo de coorte retrospectiva tem como objetivo avaliar o desfecho perinatal de gestações gemelares monocoriônicas afetadas por CIUR-s e conduzidas de forma expectante, analisando os resultados de acordo com o padrão Doppler da artéria umbilical do gêmeo menor (Tipo I: persistentemente positivo / Tipo II: persistentemente ausente ou reverso / Tipo III: intermitentemente ausente ou reverso), desde o período pré-natal até a alta hospitalar. Setenta e cinco gestações gemelares monocoriônicas diamnióticas com CIUR-s foram incluídas nesse estudo, no qual definimos restrição seletiva de crescimento como peso fetal estimado (PFE) abaixo do terceiro percentil para a idade gestacional ou ou pela presença de pelo menos dois dos quatro parâmetros contributivos: PFE abaixo do décimo percentil, circunferência abdominal abaixo do percentil 10, índice de pulsatilidade da artéria umbilical do gêmeo menor acima do percentil 95 ou discordância entre os pesos fetais estimados de 25% ou mais. Os desfechos perinatais incluíram morte perinatal, lesão neurológica, retinopatia da prematuridade (ROP), displasia broncopulmonar (DBP), enterocolite necrosante (ECN) e sepse. Resultados: A taxa de mortalidade foi de 1,33% nessa coorte. A taxa de morbidade geral foi de 28,66%, com menor incidência em gestações gemelares do Tipo I. Conclusão: Esse estudo mostra que o CIUR-s Tipo I apresenta menor morbidade do que os Tipos II e III em conduta expectante.

Objective: To evaluate perinatal morbidity and mortality of monochorionic twin pregnancies affected by Selective Intrauterine Growth Restriction (sIUGR), according to the Doppler flow pattern in the umbilical artery of the smaller twin. Methods: This retrospective cohort study aims to assess the perinatal outcome of monochorionic twin pregnancies affected by this disorder and conducted expectantly, analyzing the results according to the umbilical artery Doppler pattern of the smaller twin (Type I: persistently forward / Type II: persistently absent or reversed / Type III: intermittently absent or reversed, from prenatal period to hospital discharge. Seventy five monochorionic diamniotic twin pregnancies with sIUGR were included in this study, in which we defined selective growth restriction as estimated fetal weight (EFW) of one twin less than the third centile or in the presence of at least two out of four contributory parameters: EFW less than the 10th percentile when associated with AC of one twin less than the 10th centile, EFW discordance of 25% or more, and umbilical artery (UA) pulsatility index (PI) of the smaller twin above the 95th centile. Perinatal outcomes included perinatal death, neurological injury, retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC) and sepsis. Results: The mortality rate was 1.33% in this cohort. Overall morbidity rate was 28.66%, with lower incidence in Type I twin pregnancies. Conclusion: This study shows that sIUGR Type I has lower morbidity than Types II and III in expectant management.

Influence of heritability on craniofacial soft tissue characteristics of monozygotic twins, dizygotic twins, and their siblings using Falconer's method and principal components analysis / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to investigate the influence of heritability on the craniofacial soft tissue cephalometric characteristics of monozygotic (MZ) twins, dizygotic (DZ) twins, and their siblings (SIB). METHODS: The samples comprised Korean adult twins and their siblings (mean age, 39.8 years; MZ group, n = 36 pairs; DZ group, n = 13 pairs of the same gender; and SIB group, n = 26 pairs of the same gender). Thirty cephalometric variables were measured to characterize facial profile, facial height, soft-tissue thickness, and projection of nose and lip. Falconer's method was used to calculate heritability (low heritability, h2 0.9). After principal components analysis (PCA) was performed to extract the models, we calculated the intraclass correlation coefficient (ICC) value and heritability of each component. RESULTS: The MZ group exhibited higher ICC values for all cephalometric variables than DZ and SIB groups. Among cephalometric variables, the highest h2 (MZ-DZ) and h2 (MZ-SIB) values were observed for the nasolabial angle (NLA, 1.544 and 2.036), chin angle (1.342 and 1.112), soft tissue chin thickness (2.872 and 1.226), and upper lip thickness ratio (1.592 and 1.026). PCA derived eight components with 84.5% of a cumulative explanation. The components that exhibited higher values of h2 (MZ-DZ) and h2 (MZ-SIB) were PCA2, which includes facial convexity, NLA, and nose projection (1.026 and 0.972), and PCA7, which includes chin angle and soft tissue chin thickness (2.107 and 1.169). CONCLUSIONS: The nose and soft tissue chin were more influenced by genetic factors than other soft tissues.