The MGS-C sample has been previously described in detail (Sanders et al. 2008; Shi et al. 2009; Sanders et al. 2010). In summary, Knowledge Networks, Inc., a survey research company, recruited self-identified non-Hispanic European-American and African-Americans from a nationwide panel of survey participants, which was assembled by random digit dialing except 772 of the African-Americans were recruited through a subcontract to Survey Sampling International by internet banner advertisement recruitment. The institutional review board approval was obtained at NorthShore University HealthSystem and participants completed an online consent with an identical hard-copy consent signed at venipuncture. Participants completed an online questionnaire, available at http://nimhgenetics.org, which included items on height and current weight. BMI was calculated from respondents' self-reported height and current weight. Participants were removed from data analysis if there were missing data on either height or weight or if calculated BMI was less than 15 or greater than 60 as values not in this range were likely data entry errors. There were 2,653 European-Americans and 973 African Americans included in the present study. Phenotypic details are displayed in Table 1 with full sample characteristics found in Sanders et al. (2010).
