Replication in UKB is particularly reassuring considering the differences between the UKB and MVP cohorts. Presently the UKB has more analyzable subjects (~500,000) than the MVP, but the MVP is still recruiting towards a final sample size of at least 1,000,000. MVP, being a sample of US veterans, includes disproportionately many subjects with military-related illnesses (like PTSD) and therefore is highly informative for such traits; its subjects tend to be lower in socioeconomic status than the population-based UKB (a means test is applied to determine eligibility for VA care). Owing to its military origin, MVP has a strong male predominance. The MVP moreover has strong representation of non-European ancestry populations and therefore is a major resource for mapping in, especially, African-Americans.
