Are there Human-Specific Diseases?

Comparative medicine has a long and strong tradition, in which studies of naturally occurring diseases in other animals has shed much light on the origins and pathophysiology of human ailments. Less attention has been paid to the flip side of the coin, i.e., are there diseases that are preferentially or uniquely human? In our studies of the comparative biology of humans and other hominids (the so-called "great apes”), we have encountered several surprising examples in which common human diseases appear to be either absent in these closest living evolutionary cousins, or manifest in a rather modified form. Conversely, examples exist of diseases apparently not common in humans but prominent in other hominids. Given the close genetic similarity of all these species, it is worth investigating these differences, with the goal of better understanding the pathological processes involved, for the benefit of both humans and “great apes." This talk will present a summary of available information on this topic, mentioning genetic and molecular explanations to date and related aspects of sialic acid biology differences between humans and other hominids.