Coverage (and corresponding number of samples) for fixed budget of $300,000. (a) Effective sample size in sequencing-based GWAS as function of number of samples and resulting coverage. Cost assumptions: $30 per sample preparation cost, $133 per 1x sequencing cost (see main text).(b) Ratio of expected association statistic (effective sample size) in sequencing-based GWAS vs. array-based GWAS at $400/sample, as a function of sample preparation and sequencing costs. Expected association statistics for sequencing-based GWAS are based on optimum coverage and number of samples (assuming arbitrarily large number of samples available) subject to budget constraint. The optimum coverage and number of samples varies at different points on the graph (not shown). Black dot denotes $30 sample preparation cost and $133 per 1x.
