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Digestive Diseases and Sciences Jun 2022Twin studies have long been used to infer heritability. Within the 'omics era, twin cohorts have even greater research potential. This study describes the formation of...
BACKGROUND AND AIMS
Twin studies have long been used to infer heritability. Within the 'omics era, twin cohorts have even greater research potential. This study describes the formation of the UK IBD Twin Registry and analysis of concordance and environmental factors.
METHOD
Twin pairs with IBD were recruited by advertising via IBD charities and social media, re-tracing a dormant IBD database and clinician referral. Details of zygosity, concordance, disease history and environmental factors were assessed. Pair concordance was calculated, and environmental factors were analysed with logistic regression models adjusted for zygosity and concordance.
RESULTS
Ninety-one twin pairs were included in the analysis; forty-two with CD and forty-nine with UC. More MZ twin pairs with CD were concordant compared with DZ pairs, thus inferring heritability (Chi-sq. 15.6. P < 0.001). In UC, MZ concordance was also numerically greater. Cigarette smoking was predictive of CD (OR 2.66, 95% CI 1.16 to 6.07 P = 0.02); there may be an independent association with cannabis smoking (OR 2.59 95% CI 0.89 to 7.55 P = 0.08). Breastfeeding was protective against UC (OR 0.48, 95% CI 0.25-0.93, P = 0.03), but not CD. Self-reports of less occurrences of gastroenteritis than peers were protective against future UC onset (OR 0.33 95% CI 0.15 to 0.74, P = 0.01). Method of delivery, parental attitudes towards hygiene and recall of diet did not impact future IBD concordance.
CONCLUSIONS
This study supports the heritability of IBD. Twin study analysis was able to elucidate environmental factors associated with IBD.
Topics: Diseases in Twins; Humans; Inflammatory Bowel Diseases; Registries; Risk Factors; Twins, Dizygotic; Twins, Monozygotic; United Kingdom
PubMed: 34097167
DOI: 10.1007/s10620-021-07080-5 -
Frontiers in Cellular and Infection... 2021The objectives are to estimate the vertical transmission rate in twins relative to singleton pregnancies, to evaluate whether discordance within twin pairs is rare, and...
OBJECTIVE
The objectives are to estimate the vertical transmission rate in twins relative to singleton pregnancies, to evaluate whether discordance within twin pairs is rare, and to characterize concordance within monozygotic and dizygotic twin pairs in relation to hereditability.
METHODS
We first sought to estimate the vertical transmission rate of congenital CMV infection in twins by gathering cohort-based studies of congenital CMV in which vertical transmission in both singleton and twin pregnancies was reported. This also allowed us to compare singleton and twin infection rates. From the above studies and other large cohorts of congenitally infected infants, the percentage of discordantly infected twin pairs determined whether this is a rare phenomenon. Theorizing discordance is not rare, we then analyzed data from cases with twin outcomes for congenital CMV infection, according to whether the twins were monozygotic or dizygotic, and calculated their corresponding concordance rates to estimate the broad-sense heritability. Lastly, we described other factors that might affect vertical transmission.
RESULTS
From five articles following at-risk pregnancies, the rate of vertical transmission in twin pregnancies is 58.7% (95% CI 43.3-72.3%) whereas in singleton pregnancies it is 31.4% (95% CI: 29.0-34.0%) = 0.0002. Of ten studies of larger cohorts of infants with congenital CMV infection, 21 of 42 twin pairs with at least one twin infected were discordant for congenital CMV (50.0%, 95% CI: 34.4-65.6%) indicating discordance of congenital CMV infection in twin pairs is not rare. Of 28 studies covering 37 twin pairs where at least one twin had congenital CMV, and zygosity was known, eleven of thirteen monozygotic twin pairs (84.6%; 95% CI: 53.7-97.3%) were concordant for CMV infection, and nine of twenty-four dizygotic twin pairs (37.5%; 95% CI: 19.6-59.2%) were concordant for infection giving an estimated hereditability of 94.2%. Within these 37 twin pairs, factors such as primary or recurrent maternal infection, prematurity, growth discordance, and sex are described; however, in many of these cases these factors are unknown.
CONCLUSION
The rate of vertical transmission of congenital CMV is higher for twins than singletons. Discordance of congenital CMV in twins is not rare and suggests a possible genetic susceptibility to congenital CMV.
Topics: Cytomegalovirus; Diseases in Twins; Female; Humans; Pregnancy; Pregnancy, Twin; Twins, Dizygotic; Twins, Monozygotic
PubMed: 34350131
DOI: 10.3389/fcimb.2021.676988 -
Prenatal Diagnosis Jun 2020Monochorionic diamniotic twins occur in about 1 in 300 pregnancies. Compared with dichorionic twins, they face increased risks because of the shared circulation. In... (Review)
Review
Monochorionic diamniotic twins occur in about 1 in 300 pregnancies. Compared with dichorionic twins, they face increased risks because of the shared circulation. In about 15%, an imbalance in blood exchange occurs, such as twin-twin transfusion syndrome and twin anemia polycythemia sequence. In this review, we summarize the latest evidence on the management of monochorionic diamniotic twin pregnancies and their specific complications, with a focus on information that is relevant for prospective parents.
Topics: Female; Fetofetal Transfusion; Humans; Male; Parents; Patient Education as Topic; Pregnancy; Pregnancy Complications; Pregnancy, Twin; Truth Disclosure; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32279339
DOI: 10.1002/pd.5705 -
Twin Research and Human Genetics : the... Dec 2019The Netherlands Twin Register (NTR) is a national register in which twins, multiples and their parents, siblings, spouses and other family members participate. Here we...
The Netherlands Twin Register (NTR) is a national register in which twins, multiples and their parents, siblings, spouses and other family members participate. Here we describe the NTR resources that were created from more than 30 years of data collections; the development and maintenance of the newly developed database systems, and the possibilities these resources create for future research. Since the early 1980s, the NTR has enrolled around 120,000 twins and a roughly equal number of their relatives. The majority of twin families have participated in survey studies, and subsamples took part in biomaterial collection (e.g., DNA) and dedicated projects, for example, for neuropsychological, biomarker and behavioral traits. The recruitment into the NTR is all inclusive without any restrictions on enrollment. These resources - the longitudinal phenotyping, the extended pedigree structures and the multigeneration genotyping - allow for future twin-family research that will contribute to gene discovery, causality modeling, and studies of genetic and cultural inheritance.
Topics: Adolescent; Biological Specimen Banks; Biomarkers; Child; Child, Preschool; Databases, Factual; Diseases in Twins; Family; Female; Follow-Up Studies; Health Status; Humans; Infant; Infant, Newborn; Longitudinal Studies; Male; Netherlands; Neuropsychological Tests; Pedigree; Phenotype; Registries; Research Design; Surveys and Questionnaires; Twins, Dizygotic; Twins, Monozygotic
PubMed: 31666148
DOI: 10.1017/thg.2019.93 -
Twin Research and Human Genetics : the... Apr 2022It is widely recognized that dizygotic twinning (DZT) runs in families, but estimates of heritability from twin and family data are remarkably scarce and vary...
It is widely recognized that dizygotic twinning (DZT) runs in families, but estimates of heritability from twin and family data are remarkably scarce and vary considerably. Here, we traced seven large, sometimes historical, multigeneration pedigrees from West Africans, fin de siècle French Jews, Canadians (two pedigrees), and the French royal family, in which twin births were recorded. We estimated heritability of twinning (of all types) as zygosity information was not available, diluting the true DZT heritability by a third or so. The estimates in the range 8-20% are remarkably consistent across time (8-19 generations) and ethnicities and also consistent with twin and family estimates.
Topics: Canada; Humans; Pedigree; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35593089
DOI: 10.1017/thg.2022.14 -
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 -
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 -
Ultrasound in Obstetrics & Gynecology :... Feb 2024To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons.
OBJECTIVE
To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons.
METHODS
Gestational-age- and chorionicity-specific reference distributions for singleton percentiles and EFW were fitted to data on 4391 twin pregnancies with two liveborn fetuses from four European centers, including 3323 dichorionic (DC) and 1068 monochorionic diamniotic (MCDA) twin pregnancies. Gestational age was derived using the larger of the two crown-rump length measurements obtained during the first trimester of pregnancy. EFW was obtained from ultrasound measurements of head circumference, abdominal circumference and femur length using the Hadlock formula. Singleton percentiles were obtained using the Fetal Medicine Foundation population weight charts for singleton pregnancies. Hierarchical models were fitted to singleton Z-scores with autoregressive terms for serial correlations within the same fetus and between twins from the same pregnancy. Separate models were fitted for DC and MCDA twins.
RESULTS
Fetuses from twin pregnancies tended to be smaller than singletons at the earliest gestational ages (16 weeks for MCDA and 20 weeks for DC twins). This was followed by a period of catch-up growth until around 24 weeks. After that, both DC and MCDA twins showed reduced growth. In DC twins, the EFW corresponding to the 50 percentile was at the 50 percentile of singleton pregnancies at 23 weeks, the 43 percentile at 28 weeks, the 32 percentile at 32 weeks and the 22 percentile at 36 weeks. In MCDA twins, the EFW corresponding to the 50 percentile was at the 36 percentile of singleton pregnancies at 24 weeks, the 29 percentile at 28 weeks, the 19 percentile at 32 weeks and the 12 percentile at 36 weeks.
CONCLUSIONS
In DC and, to a greater extent, MCDA twin pregnancies, fetal growth is reduced compared with that observed in singleton pregnancies. Furthermore, after 24 weeks, the divergence in growth trajectories between twin and singleton pregnancies becomes more pronounced as gestational age increases. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Pregnancy; Female; Humans; Perinatology; Fetal Development; Pregnancy, Twin; Gestational Age; Fetal Weight; Twins, Dizygotic; Retrospective Studies; Ultrasonography, Prenatal; Fetal Growth Retardation
PubMed: 37842873
DOI: 10.1002/uog.27514 -
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 -
The Journal of Maternal-fetal &... Jul 2021This study aimed to compare obstetrical complications and neonatal outcomes between monochorionic and dichorionic discordant twin pregnancies.
OBJECTIVES
This study aimed to compare obstetrical complications and neonatal outcomes between monochorionic and dichorionic discordant twin pregnancies.
STUDY DESIGN
We enrolled 296 patients with twin pregnancy who delivered at Busan Paik Hospital between January 2014 and December 2017. The prevalence of obstetrical complications, neonatal mortality between monochorionic and dichorionic twins was compared. We also investigated whether there is a difference in neonatal outcome and neonatal morbidity between monochorionic discordant twins without monochorionic-specific complications and dichorionic discordant twins.
RESULTS
The risk of fetal death (13.2 versus 5.2%, = .025) and inter twin birth weight discordance (35.1 versus 20.8%, = .031) is increased in monochorionic twins than in dichorionic twins. However, no difference was noted in obstetrical complication and neonatal mortality and morbidity between two groups. Among twin pregnancies with intertwin birth weight discordance, after excluding fetal death and monochorionic specific complication, there was no difference in obstetrical complication and neonatal mortality and morbidity according to chorionicity. There was no difference in neonatal morbidity between monochorionic twins and dichorionic twins when comparing larger neonates and smaller neonates of each group.
CONCLUSIONS
Risk of birth weight discordance is higher in monochorionic twin but no significant difference was observed in maternal outcomes, neonatal mortality and morbidity between noncomplicated monochorionic and dichorionic discordant twins.
Topics: Birth Weight; Chorion; Female; Humans; Infant Mortality; Infant, Newborn; Pregnancy; Pregnancy Outcome; Pregnancy, Twin; Twins, Dizygotic; Twins, Monozygotic
PubMed: 31416367
DOI: 10.1080/14767058.2019.1657085