Figure 1. Q-Q Plot of Observed versus Expected P-values Comparing the Burden of Novel Variants in Protein-Coding Genes in Familial Pulmonary Fibrosis Cases and Controls.
Novel variants in European 78 pulmonary fibrosis probands and 2,816 controls were identified and their frequencies compared by Fisher’s exact test. The distribution of observed P-values for each gene was compared to the distribution of expected P-values. (a) Analysis of novel variants that are either damaging or missense at positions that are highly conserved across phylogeny. (b) Analysis of novel damaging variants. The distribution of observed P-values generally follows the expected distribution for damaging plus conserved missense variants, while for damaging mutations only, many P-values are lower than expected due to a paucity of variants. The damaging plus missense set shows two genes (RTEL1 and PARN) with P-values at or near genome-wide significance, while the damaging variant set shows one gene, PARN, with an observed P-value well outside the expected distribution.