Evidence for functional redundancy in duplicated disease genes.

<p>Comparing with duplicated non-disease genes (ND) of similar duplication age (represented by branch length, see Methods), monogenic disease genes (MD) tend have A) higher co-expression co-efficient (p-value = 1.69×10⁻³, Hypergeometric Distribution test), C) higher sequence similarity (p-value = 1.66×10⁻³, Hypergeometric Distribution test). Results in A) can be repeated using another set of gene expression data (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003073#pcbi.1003073.s003" target="_blank">Figure S3</a>). P-values shown in the boxplots (B and D) were calculated using two-sample Wilcoxon Rank Sum Test; see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003073#s4" target="_blank">Materials and Methods</a> for more details regarding the statistical tests. Numbers shown next the boxplots are the numbers of valid samples (after removing samples with missing values).