To further investigate whether our approach to selecting the 47 genes is efficient, we compared the results with a similar analysis of top-ranked genes based on p values in COGA GWAS. We assigned the smallest p value of the marker mapped to a gene to represent gene-wise association significance. Then, we selected the most significant 47 genes. No functional term was significant in GO term analysis. Of note, our results were not corrected for gene length bias, a potential problem in gene-based association studies [25]. This comparison suggested that our cross-species gene ranking method may be more useful in extracting biological meaning from gene lists.
