Abstract
For the participants in the Netherlands Twin Register (NTR) we constructed the extended pedigrees which specify all relations among nuclear and larger twin families in the register. A total of 253,015 subjects from 58,645 families were linked to each other, to the degree that we had information on the relations among participants. We describe the algorithm that was applied to construct the pedigrees. For > 30,000 adolescent and adult NTR participants data were available on harmonized neuroticism scores. We analyzed these data in the Mendel software package (Lange et al., Bioinformatics 29(12):1568–1570, 2013) to estimate the contributions of additive and non-additive genetic factors. In contrast to much of the earlier work based on twin data rather than on extended pedigrees, we could also estimate the contribution of shared household effects in the presence of non-additive genetic factors. The estimated broad-sense heritability of neuroticism was 47%, with almost equal contributions of additive and non-additive (dominance) genetic factors. A shared household effect explained 13% and unique environmental factors explained the remaining 40% of the variance in neuroticism.
Highlights
Like many large twin registries worldwide, The Netherlands Twin Register (NTR) recruits twins, and their family members, including parents, siblings, spouses and offspring of twins
We analyzed a large dataset on neuroticism from twins, their biological relatives and nonbiological family members, including spouses (N > 30,000 subjects), after constructing the extended pedigrees, that link all nuclear families from the Netherlands Twin Register to each other within larger pedigrees
For the genetic analyses of neuroticism in Mendel a total of 36,639 individuals were present in a trimmed pedigree of which 31,152 were phenotyped
Summary
Like many large twin registries worldwide, The Netherlands Twin Register (NTR) recruits twins, and their family members, including parents, siblings, spouses and offspring of twins. Van den Berg et al (2014) applied IRT to neuroticism data from a large number of international cohorts with twin data (total N = 29,496 twin pairs from six cohorts) and estimated the heritability of neuroticism at 48% with roughly equal contributions of additive and non-additive genetic factors. This estimate closely resembled the estimate of 42% from a large meta-analysis of behavior genetic studies on personality including over 100,000 subjects (Vukasović and Bratko 2015). We used the Mendel software package (https://www.genetics.ucla.edu/ software/Mendel_current_doc.pdf) for the genetic analysis of neuroticism, specifying models that included variance components due to additive and non-additive genetic factors as well as to shared household
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
