Functional pathway analysis using MSigDB yielded top pathways related to regulation of vacuolar transport, regulation of skeletal muscle contraction and cellular processes relevant for cell division, however none of the pathways demonstrated an empirically significant result. Table D in S2 File in the supplementary data lists the top ten pathways, with the empirical P-value for the pathway. We examined the expression patterns of some of the top genes, using GTEx Portal (www.gtexportal.org). The gene CCDC42 is the top gene in the association analysis as well as in the gene-based analysis; expression patterns show that it is primarily expressed in the testes with no observable expression levels in any other tissue. The gene BRSK2 is expressed in several parts of the brain, with expression levels being highest in cerebellum tissues, followed by somewhat lower expression in the hippocampus and the hypothalamus. According to the database, there is some expression in the pancreas and the pituitary. Finally, ARHGEF10 shows expression mainly in tissues derived from the tibial nerve and the lung with smaller amounts of expression in a range of other tissues, including the brain.
