Browsing by Subject "DISEQUILIBRIUM"

Sort by: Order: Results:

Now showing items 1-3 of 3
  • Within-family Consortium; 23andMe Res Team; Brumpton, Ben; Sanderson, Eleanor; Heilbron, Karl; Kaprio, Jaakko; Davies, Neil M. (2020)
    Estimates from Mendelian randomization studies of unrelated individuals can be biased due to uncontrolled confounding from familial effects. Here we describe methods for within-family Mendelian randomization analyses and use simulation studies to show that family-based analyses can reduce such biases. We illustrate empirically how familial effects can affect estimates using data from 61,008 siblings from the Nord-TrOndelag Health Study and UK Biobank and replicated our findings using 222,368 siblings from 23andMe. Both Mendelian randomization estimates using unrelated individuals and within family methods reproduced established effects of lower BMI reducing risk of diabetes and high blood pressure. However, while Mendelian randomization estimates from samples of unrelated individuals suggested that taller height and lower BMI increase educational attainment, these effects were strongly attenuated in within-family Mendelian randomization analyses. Our findings indicate the necessity of controlling for population structure and familial effects in Mendelian randomization studies. Family-based study designs have been applied to resolve confounding by population stratification, dynastic effects and assortative mating in genetic association analyses. Here, Brumpton et al. describe theory and simulations for overcoming such biases in Mendelian randomization through within-family studies.
  • Haataja, Ritva; Karjalainen, Minna K.; Luukkonen, Aino; Teramo, Kari; Puttonen, Hilkka; Ojaniemi, Marja; Varilo, Teppo; Chaudhari, Bimal P.; Plunkett, Jevon; Murray, Jeffrey C.; McCarroll, Steven A.; Peltonen, Leena; Muglia, Louis J.; Palotie, Aarno; Hallman, Mikko (2011)
  • Suksi, Juhani; Tullborg, Eva-Lena; Pidchenko, Ivan; Krall, Lindsay; Sandström, Björn; Kaksonen, Kai; Vitova, Tonya; Kvashnina, Kristina O.; Göttlicher, Jörg (2021)
    Unusually high uranium (U) concentrations (up to 175 mu g/L) have been measured in groundwater at depths between 400 and 650 m at the Forsmark site, eastern Sweden. Since it is unlikely that such high concentrations formed under the stagnant and low redox groundwater conditions that currently prevail, this study employs Useries isotopes to understand how the recent evolution (