Cohort Profile: ZOE 2.0—A Community-Based Genetic Epidemiologic Study of Early Childhood Oral Health

Early childhood caries (ECC) is an aggressive form of dental caries occurring in the first five years of life. Despite its prevalence and consequences, little progress has been made in its prevention and even less is known about individuals’ susceptibility or genomic risk factors. The genome-wide association study (GWAS) of ECC (“ZOE 2.0”) is a community-based, multi-ethnic, cross-sectional, genetic epidemiologic study seeking to address this knowledge gap. This paper describes the study’s design, the cohort’s demographic profile, data domains, and key oral health outcomes. Between 2016 and 2019, the study enrolled 8059 3–5-year-old children attending public preschools in North Carolina, United States. Participants resided in 86 of the state’s 100 counties and racial/ethnic minorities predominated—for example, 48% (n = 3872) were African American, 22% white, and 20% (n = 1611) were Hispanic/Latino. Seventy-nine percent (n = 6404) of participants underwent clinical dental examinations yielding ECC outcome measures—ECC (defined at the established caries lesion threshold) prevalence was 54% and the mean number of decayed, missing, filled surfaces due to caries was eight. Nearly all (98%) examined children provided sufficient DNA from saliva for genotyping. The cohort’s community-based nature and rich data offer excellent opportunities for addressing important clinical, epidemiologic, and biological questions in early childhood.

Database of Families with Twins and Higher Order Multiples in Japanese Twins Mothers Clubs

It is desirable for twin researchers to be aware of the needs and concerns of families of multiples and provide participants with appropriate and useful feedback and advice based on scientific evidence. Our most recent database on families with twins throughout Japan is based on a questionnaire survey conducted in 2016. Mailed questionnaires, consisting of over 500 items, were used to collect the basic data. The response rate was 38% (566/1478). This is part of a nationwide study designed to assess the long-term effect of perinatal conditions on mothers of multiples. Its aim was to study the growth and development of multiples in childhood, and for the creation of a multifetal mother and child health handbook, and to conduct a genetic epidemiologic study to test the developmental origin of health and disease hypothesis. One of the ultimate aims of this research was to provide evidence-based information on parenting of multiples for families with multiples.

A powerful test for ordinal trait genetic association analysis

Response selective sampling design is commonly adopted in genetic epidemiologic study because it can substantially reduce time cost and increase power of identifying deleterious genetic variants predispose to human complex disease comparing with prospective design. The proportional odds model (POM) can be used to fit data obtained by this design. Unlike the logistic regression model, the estimated genetic effect based on POM by taking data as being enrolled prospectively is inconsistent. So the power of resulted Wald test is not satisfactory. The modified POM is suitable to fit this type of data, however, the corresponding Wald test is not optimal when the genetic effect is small. Here, we propose a new association test to handle this issue. Simulation studies show that the proposed test can control the type I error rate correctly and is more powerful than two existing methods. Finally, we applied three tests to Anticyclic Citrullinated Protein Antibody data from Genetic Workshop 16.

Japanese Database of Families with Twins and Higher-Order Multiples

To gain widespread participation, epidemiologic studies of twins from pregnancy through the childhood period are expected to reflect the needs and concerns of families and provide participants with appropriate and useful feedback based on scientific evidence. Our most recent database on families with twins throughout Japan is based on a questionnaire survey conducted from January 2010 to August 2011. Mailed or hand-delivered questionnaires, consisting of over 550 items were used to collect the basic data. The response rate was 40% (956/2,401). This is part of a nation-wide study designed to assess the long-term effect of perinatal conditions on mothers of multiples. Its aim was to study the growth and development of multiples in childhood, and to conduct a genetic epidemiologic study to test the developmental origin of health and disease hypothesis. One of the ultimate aims of this research was to provide evidence-based information on parenting multiples from pregnancy through childhood to families with multiples.