Chunk #34 — Statistical Methodology for the Analysis of Association Trajectories — Identification of significant SNPs — Significant SNPs identified by thresholding p-values by false discovery rate
In the interest of condensation of information and ease of interpretation, as well as the expectation that meaningful biological processes must extend over more than the length of a year, results are provided for 7 overlapping 3 year age ranges extending from age 12 to 24. (Ranges of years of age: 12–15, 13.5–16.5, 15–18, 16.5–19.5, 18–21, 19.5–22.5, 21–24). Medians of p-values across the age-ranges and the four phenotype groups were calculated to provide coarse-grained results. The concentration of measure of the range of p-values introduced by use of the median was considerable, particularly in the range 0 < p < 10−2 and introduced a corresponding bias in the direct application of the Storey-Tibshirani algorithm. As a consequence, the false discovery proportion threshold derived from the calculation on the raw p-values was used to determine the appropriate threshold for the control of the false discovery rate in the median p-values. A similar strategy is used to identify SNPs which had significant differential effect between sexes.
