by Penn State University. Samples were then shipped to the Virginia Institute for Psychiatric and Behavioral Genetics for genotyping. Genotyping was conducted using commercially available primer and probe sequences from TaqMan Assays-on-Demand (Applied Biosystems, Foster City, CA). Duplicate genotyping produced 100% concordance rates. For samples passing quality control (genotyping success rate > 80%), call rates for the 10 SNPs ranged from 87% to 99%. All SNPs were in Hardy-Weinberg equilibrium (minimum p > 0.2 for EAs and AAs). Of 439 EAs enrolled in Fast Track, 62% (n = 270) provided a DNA sample that was successfully genotyped at NR3C1 (intervention n = 129; control n = 141). Of 452 AAs, 62% (n = 282) were successfully genotyped (intervention n = 143; control n = 139). For EAs and AAs separately, attrition analyses comparing the genetic subsample to the complete sample on the severity-of-risk screen score found no significant differences for either intervention or control groups. Severity-of-risk screen score did not differ between control and intervention children within the genetic subsample.
