However, we note that many of the SNPs are in plausible candidate genes, including 19 genes in which mutations were previously associated with Drosophila sleep (Additional file13), and 10 genes for which the human ortholog has been associated with sleep and sleep disorders in humans, nine of which are not in LD with other genes (CG31646, dnc, Dscam, eya, l(3)82Fd, nudE, ppan, and trbl) and one (Lar) that is in LD with other potential candidate genes (Table 2). This evidence concerns the gene PTPRF and sleep disorder.