The effects of electronic medical record phenotyping details on genetic association studies: HDL-C as a case study.

Background: Biorepositories linked to de-identified electronic medical records (EMRs) have the potential to complement traditional epidemiologic studies in genotype-phenotype studies of complex human diseases and traits. A major challenge in meeting this potential is the use of EMR-derived data to extract phenotypes and covariates for genetic association studies. Unlike traditional epidemiologic data, EMR-derived data are collected for clinical care and are therefore highly variable across patients.

Genetic variants associated with warfarin dose in African-American individuals: a genome-wide association study.

Background: VKORC1 and CYP2C9 are important contributors to warfarin dose variability, but explain less variability for individuals of African descent than for those of European or Asian descent. We aimed to identify additional variants contributing to warfarin dose requirements in African Americans.

Methods: We did a genome-wide association study of discovery and replication cohorts.