Association of the GGCX (CAA)16/17 repeat polymorphism with higher warfarin dose requirements in African Americans.

Objective: Little is known about genetic contributors to higher than usual warfarin dose requirements, particularly for African Americans. This study tested the hypothesis that the γ-glutamyl carboxylase (GGCX) genotype contributes to warfarin dose requirements greater than 7.5 mg/day in an African American population.