Table 2 lists the 16 diseases associated with the most genes, using an association threshold of 0.05. (Disease-gene profile overlaps have scores ranging from 0 to 24.5 with a mean of 0.04). Figure 5 shows the distribution of the number of genes using this threshold. Cancers tend to have the largest number of candidate genes, with the highest value of 197 genes for lung cancer. Next ranking are well studied common diseases such as asthma, hypertension, inflammation, obesity, Alzheimer's disease, epilepsy, atherosclerosis and deafness. The number of genes associated with a particular disease primarily reflects the complexity of phenotype, but may also partly reflect the current state of knowledge. Not surprisingly, nominally monogenic diseases tend to have the least number of candidate genes. However, these are often not monogenic in this analysis. For example, Phenylketonuria (PKU) has 14 associated genes. As expected, in this case the primary disease gene (PAH – phenylalanine hydroxylase) has a very high linkage to the disease, with a score of 23, while all other genes have scores less than 0.5. The web resource provides a ranked list of candidate genes for each disease.
