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Journal of Neural Transmission (Vienna,... Nov 2020Twin studies of psychiatric disorders such as schizophrenia and autism spectrum disorder have employed epidemiological approaches that determine heritability by... (Review)
Review
Twin studies of psychiatric disorders such as schizophrenia and autism spectrum disorder have employed epidemiological approaches that determine heritability by comparing the concordance rate between monozygotic twins (MZs) and dizygotic twins. The basis for these studies is that MZs share 100% of their genetic information. Recently, biological studies based on molecular methods are now being increasingly applied to examine the differences between MZs discordance for psychiatric disorders to unravel their possible causes. Although recent advances in next-generation sequencing have increased the accuracy of this line of research, there has been greater emphasis placed on epigenetic changes versus DNA sequence changes as the probable cause of discordant psychiatric disorders in MZs. Since the epigenetic status differs in each tissue type, in addition to the DNA from the peripheral blood, studies using DNA from nerve cells induced from postmortem brains or induced pluripotent stem cells are being carried out. Although it was originally thought that epigenetic changes occurred as a result of environmental factors, and thus were not transmittable, it is now known that such changes might possibly be transmitted between generations. Therefore, the potential possible effects of intestinal flora inside the body are currently being investigated as a cause of discordance in MZs. As a result, twin studies of psychiatric disorders are greatly contributing to the elucidation of genetic and environmental factors in the etiology of psychiatric conditions.
Topics: Autism Spectrum Disorder; Epigenesis, Genetic; Humans; Schizophrenia; Twin Studies as Topic; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32285255
DOI: 10.1007/s00702-020-02188-w -
International Journal of Molecular... Sep 2021The rearrangement is associated with an unfavorable prognosis in infant acute lymphocytic leukemia (ALL). Discordant ALL in monozygotic twins is uncommon and represents...
The rearrangement is associated with an unfavorable prognosis in infant acute lymphocytic leukemia (ALL). Discordant ALL in monozygotic twins is uncommon and represents an attractive resource to evaluate intrauterine environment-genetic interplay in ALL. Mutational and epigenetic profiles were characterized for a discordant -rearranged infant monozygotic twin pair and their parents, and they were compared to three independent /-positive ALL infants, in which the DNA methylation and gene expression profiles were investigated. A de novo Q61H NRAS mutation was detected in the affected twin at diagnosis and backtracked in both twins at birth. The rearrangement was absent at birth in both twins. Genetic analyses conducted at birth gave more insights into the timing of the mutation hit. We identified correlations between DNA methylation and gene expression changes for 32 genes in the three independent affected versus remitted patients. The strongest correlations were observed for the , , , , and genes. This epigenetic signature could be a putative target for the development of novel epigenetic-based therapies and could help in explaining the molecular mechanisms characterizing ALL infants with fusions.
Topics: Alleles; Computational Biology; CpG Islands; DNA Methylation; DNA-Binding Proteins; Epigenesis, Genetic; Epigenomics; Female; Gene Expression Regulation; Gene Rearrangement; Genotype; Histone-Lysine N-Methyltransferase; Humans; Infant, Newborn; Male; Myeloid-Lymphoid Leukemia Protein; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Transcriptional Elongation Factors; Twins, Monozygotic; Exome Sequencing
PubMed: 34575904
DOI: 10.3390/ijms22189740 -
Twin Research and Human Genetics : the... Dec 2022Quadruplets are at elevated physical risks at prenatal, perinatal, and postnatal levels, relative to twins. A brief review of this area is followed by discussion of a... (Review)
Review
Quadruplets: Risks, Outcomes and a Set of Four/Twin Research Reviews and a Lawsuit: Antenatal Corticosteroids and Twins' Neonatal Outcomes; Fathers of Twins; Doppelgängers and Similarity; Monozygotic Co-Twin Difference in Asymmetric Pigmented Paravenous Chorioretinal Atrophy/In the News:...
Quadruplets are at elevated physical risks at prenatal, perinatal, and postnatal levels, relative to twins. A brief review of this area is followed by discussion of a female quadruplet with three co-quadruplet brothers. Next, several timely twin research reports are examined. The topics include antenatal corticosteroids and twins' neonatal outcomes, the meaning of fatherhood in families with twins, what doppelgängers (look-alikes) reveal about physical and behavioral similarity, and monozygotic (MZ) co-twin discordance for asymmetric pigmented paravenous chorioretinal atrophy. A lawsuit involving alleged cheating on a medical school examination by identical twins is also reviewed. General interest stories cover opposite-sex twin Holocaust survivors, twin models at a Gucci fashion show, twins with different fathers, reunited female twins who entered the same convent, the death of an MZ female twin soldier during training, and the surgical separation of conjoined twins in Brazil.
Topics: Female; Humans; Infant, Newborn; Male; Pregnancy; Adrenal Cortex Hormones; Holocaust; Military Personnel; Survivors; Twins, Conjoined; Twins, Monozygotic
PubMed: 36633100
DOI: 10.1017/thg.2022.41 -
Twin Research and Human Genetics : the... Dec 2019The South Korean Twin Registry (SKTR) is an ongoing nationwide volunteer registry of South Korean twins and their families. Since its inception, from preschooler to...
The South Korean Twin Registry (SKTR) is an ongoing nationwide volunteer registry of South Korean twins and their families. Since its inception, from preschooler to young adult, twins have been registered with the SKTR and have demonstrated that relative influences of genetic and environmental factors explaining individual differences in various psychological, mental health and physical traits in South Koreans are similar to those found in many Western twin studies. Currently, studies at the SKTR focus on identification of the process of gene-by-environment interactions as well as developmental differences in genetic and environmental influences on psychological and mental health traits in South Koreans. This report provides a brief overview, recruitment strategies, current samples, zygosity assessment, measures and future directions of the SKTR.
Topics: Adolescent; Adult; Child; Diseases in Twins; Female; Follow-Up Studies; Gene-Environment Interaction; Humans; Male; Models, Genetic; Registries; Republic of Korea; Twins, Dizygotic; Twins, Monozygotic; Young Adult
PubMed: 31875802
DOI: 10.1017/thg.2019.115 -
Genes Sep 2023Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently...
Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently observed in boys and in twins. The exact cause of isolated EA remains unknown; a multifactorial etiology, including epigenetic gene expression modifications, is considered. The study included six pairs of twins (three pairs of monozygotic twins and three pairs of dizygotic twins) in which one child was born with EA as an isolated defect, while the other twin was healthy. DNA samples were obtained from the blood and esophageal tissue of the child with EA as well as from the blood of the healthy twin. The reduced representation bisulfite sequencing (RRBS) technique was employed for a whole-genome methylation analysis. The analyses focused on comparing the CpG island methylation profiles between patients with EA and their healthy siblings. Hypermethylation in the promoters of 219 genes and hypomethylation in the promoters of 78 genes were observed. A pathway enrichment analysis revealed the statistically significant differences in methylation profile of 10 hypermethylated genes in the Rho GTPase pathway, previously undescribed in the field of EA (, and ).
Topics: Male; Child; Humans; Esophageal Atresia; Twins, Monozygotic; Twins, Dizygotic; CpG Islands; Epigenesis, Genetic; Proto-Oncogene Proteins; Guanine Nucleotide Exchange Factors; Rho Guanine Nucleotide Exchange Factors
PubMed: 37761962
DOI: 10.3390/genes14091822 -
Twin Research and Human Genetics : the... Apr 2022Living in the same household exposes family members to shared environments and may be reflected in estimates of shared environment in twin analyses. The age at the...
Living in the same household exposes family members to shared environments and may be reflected in estimates of shared environment in twin analyses. The age at the separation of cotwins in a twin pair marks the end of such shared exposure, and the age of separation is commonly self-reported in studies. The objective of the study was to summarize the age at separation from residential records and use it to validate with self-reported separation status and age at the third and fourth wave of data collection in the FinnTwin12 cohort. Age at separation was generated from the address information, linking it to the Finnish Population information system since birth. Descriptive statistics by sex and zygosity are presented. The mean age at separation from residential records was 20.36 years old. Women separated earlier than men and dizygotic pairs earlier than monozygotic pairs. We also calculated the sensitivity and specificity with the self-reported separation status at waves 3 and 4, and interrater reliability with the self-reported separation age at wave 4. Age at separation from residential records had a relatively poor agreement with the self-report. This work enables us to use a more precise and objective measure for the shared environment in future twin studies.
Topics: Adult; Cohort Studies; Diseases in Twins; Family; Female; Humans; Male; Reproducibility of Results; Twins; Twins, Dizygotic; Twins, Monozygotic; Young Adult
PubMed: 35603696
DOI: 10.1017/thg.2022.17 -
Twin Research and Human Genetics : the... Dec 2019Here we provide an update of the 2013 report on the Nigerian Twin and Sibling Registry (NTSR). The major aim of the NTSR is to understand genetic and environmental...
Here we provide an update of the 2013 report on the Nigerian Twin and Sibling Registry (NTSR). The major aim of the NTSR is to understand genetic and environmental influences and their interplay in psychological and mental health development in Nigerian children and adolescents. Africans have the highest twin birth rates among all human populations, and Nigeria is the most populous country in Africa. Due to its combination of large population and high twin birth rates, Nigeria has one of the largest twin populations in the world. In this article, we provide current updates on the NTSR samples recruited, recruitment procedures, zygosity assessment and findings emerging from the NTSR.
Topics: Adolescent; Adult; Birth Rate; Child; Child, Preschool; Diseases in Twins; Female; Follow-Up Studies; Humans; Male; Mental Health; Nigeria; Registries; Siblings; Twins, Dizygotic; Twins, Monozygotic; Young Adult
PubMed: 31796140
DOI: 10.1017/thg.2019.110 -
Prenatal Diagnosis Aug 2021To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age.
OBJECTIVE
To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age.
METHODS
We reviewed all twin pregnancies undergoing first trimester screening (FTS) with nuchal translucency from April 2009 to December 2012 with sonographic determination of chorionicity. Cases were linked to newborn screening (NBS) results and zygosity estimated based on rates of fetal sex discordance. The ratio of DC to MC placentation by maternal age was calculated.
RESULTS
We identified 11,351 twin pregnancies with FTS and documented chorionicity. Among these, 7,861 (64.2%) had linked data on FTS and NBS to allow estimation of zygosity based on neonatal sex. Of these, 1,464 (18.6%) were MC and 6,406 (81.4%) DC. The MC twin rate remained constant while the DC twin rate increased with maternal age until 40y. At < 20y, 55% of twin pregnancies were monozygotic (MZ), as compared to 29% at ≥ 40y. Of MZ twins, 38% were DC at < 20y, while 53% were DC at ≥ 40y.
CONCLUSIONS
Our data suggest a relationship of both zygosity and chorionicity with maternal age. DZ twinning increased with maternal age, while among MZ twins, the proportion that were DC also increased with maternal age.
Topics: Chorion; Female; Gestational Age; Humans; Infant, Newborn; Maternal Age; Pregnancy; Pregnancy, Twin; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35280337
DOI: 10.1002/pd.5997 -
The Journal of Adolescent Health :... Aug 2022Parenting style has been associated with children's weight-related outcomes and health behaviors, but this relationship may be confounded by genetic influences. Using a...
PURPOSE
Parenting style has been associated with children's weight-related outcomes and health behaviors, but this relationship may be confounded by genetic influences. Using a twin design to better control for genetics and shared home environments, this study aimed to estimate the longitudinal parental effects on obesity, smoking, and drinking in children and adolescents.
METHODS
Data were retrieved from the first two waves of the German Twin Family Panel. A total of 631 pairs of same-sex monozygotic twins were analyzed, including three birth cohorts aged 5, 11, and 17 years. Self-reported parenting styles were measured in five dimensions: emotional warmth, psychological control, negative communication, monitoring, and inconsistent parenting. Outcome variables included children's body mass index z-score (BMIz) and smoking and alcohol drinking frequency. The differencing method was used to examine the relationship between within-monozygotic pair differences in parenting styles and health outcomes, controlling for differences at baseline, genetic influences, and other shared characteristics between twins.
RESULTS
Controlling for genetics, shared environmental effects, and body weight status at baseline, the twin who received harsher parenting in communication had lower BMI than their cotwin. Subgroup analyses found that negative communication had a stronger impact on the youngest cohort and female twins. Paternal parenting differentially relates to child weight compared to maternal parenting. No concurrent and long-lasting effects of paternal parenting on smoking and drinking were found.
DISCUSSION
The twin study design is a unique epidemiological tool to measure the contribution of genetics as opposed to the environment, to a given health trait. This study found that negative communication was associated with lower BMI in German twin families. However, it failed to identify strong evidence for the causal link between other parenting dimensions and child's weight status and alcohol and tobacco use. More twin studies with objective measurements are warranted to understand the critical role of parenting, especially family communication, in predicting children's BMIs and their health behaviors across cultures.
Topics: Adolescent; Child; Female; Humans; Male; Obesity; Parenting; Parents; Smoking; Twins, Monozygotic
PubMed: 35550332
DOI: 10.1016/j.jadohealth.2022.02.016 -
Twin Research and Human Genetics : the... Dec 2019The Boston University Twin Project (BUTP) uses a multimethod, longitudinal approach to study the role of genetic and environmental factors on the development of child... (Clinical Trial)
Clinical Trial
The Boston University Twin Project (BUTP) uses a multimethod, longitudinal approach to study the role of genetic and environmental factors on the development of child temperament and related behaviors in early childhood. There are two phases in this project. The first, described in the previous Twin Research and Human Genetics special issue on twin registries, focused on activity level and comprised over 300 twin pairs assessed in the home and laboratory at ages 2 and 3. In this article, we describe subject recruitment, sample characteristics, and study procedures and measures of the second phase of the BUTP. This recent study focuses more broadly on the development of multiple temperament dimensions and explores associations between temperament trajectories, parenting and child adjustment in a new cohort of approximately 300 twin pairs assessed at 3, 4 and 5 years of age.
Topics: Child; Female; Humans; Male; Temperament; Twins, Dizygotic; Twins, Monozygotic; Universities
PubMed: 31514760
DOI: 10.1017/thg.2019.58