Twins Born in Guangzhou

Study Overview
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Brief Summary
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The 2-BIG is a twin birth cohort study located in Guangzhou, China.Its initial aim is to facilitate research on understanding the interplay between genes and environmental factors on disease etiology. Data are collected regarding environmental, family and lifestyle exposures on twins from birth to 18 years old. Biological samples including blood and tissue samples are also collected from the twins and their parents.

Detailed Description
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Twins share the same intrauterine environment and the early family environment. When conducting research of chronic disease etiology, twins cohort can be a good control of bias from age, gender, genetic and early environment. Twin-based designs provide an estimate of the relative contribution of genetic and non-genetic factors to a specific phenotype. Twins study has an advantage of calculating heritability of traits. Since heritability of traits is various from different populations. It is important to establish database to calculate the heritability of traits associated with chronic major diseases in Chinese population. Twins cohort is rare in China at present. Therefore, extensive information including physical characteristics, mental health, and behaviors is collected from both twins and their parents. Longitudinal follow-up and surveillance of common diseases are also to be conducted. The 2-BIG aims to explore epigenetic markers and genes related to health status, as well as gene-environment interactions on diseases, both in intrauterine and childhood stages, especially in Chinese population.

Official Title
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Twins Born in Guangzhou Cohort Study

Conditions
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Twin Diseases, Immune Development, Childhood Obesity, Host and Microbiome, Neurodevelopment

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Live twins delivered in Guangzhou Women and Children's Medical Center Permanent residents or families intended to remain in Guangzhou with their children for no less than 3 years Baseline information during pregnancy available

Ages Eligible for Study
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Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Identical Twins<br>Twins develop from one zygote with no intervention | Other: No intervention<br> <br> |
| Dizygotic Twins<br>Twins develop from two different zygote with no intervention | Other: No intervention<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neurodevelopment at early childhood | Including adaptive, gross motor, fine motor, language, and social function; assessed using Gesell Developmental Schedules. | At age of 1 year old | 
| Intelligence quotient | Assessed using the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition including 5 verbal and 3 performance subtests. Intelligence quotient ranges 40-160, in which under 70 is defined as mental retardation. The total score was calculated by an online system. | At age of 6 years old | 
| Change of gene expression during childhood | DNA methylation, histone acetylation etc. assessed by analyses of blood samples | Age at 1 year , 6 years, 12years and 18years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of intestinal flora during early childhood | Assessed by analyses of stool samples | Age at 6 weeks, 6 months, 1 year , 3 years,6 years, 12years and 18years | 
| Changes of body composition and bone density during early childhood | Body composition and bone density are assessed using Dual Energy X-Ray Absorptiometry | At birth, age of 6 weeks, 6 months, 1 year , 3 years,6 years, 12years and 18years | 
| Height in kilometer changes during childhood | Measured by nurses in clinic | At birth, age of 6 weeks, 6 months, 1 year, 3 years,6 years, 12years and 18year | 
| Weight in kilogram changes during childhood | Measured by nurses in clinic | At birth, age of 6 weeks, 6 months, 1 year, 3 years,6 years, 12years and 18year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Twin, Early Development, Cohort