Playing the genome card

In the 1990s, prominent biologists and journalists predicted that by 2020 each of us would carry a genome card, which would allow physicians to access our entire genome sequence and routinely use this information to diagnose and treat common and debilitating conditions. This is not yet the case. Why not? Common and debilitating diseases are rarely caused by single-gene mutations, and this was recognized before these genome card predictions had been made. Debilitating conditions, including common psychiatric disorders, are typically caused either by rare mutations or by complex interactions of many genes, each having a small effect, and epigenetic, environmental, and microbial factors. In such cases, having a complete genome sequence may have limited utility in diagnosis and treatment. Genome sequencing technologies have transformed biological research in many ways, but had a much smaller effect than expected on treatments of common diseases. Thus, early proponents of genome sequencing effectively "mis-promised" its benefits. One reason may be that there are incentives for both biologists and journalists to tell simple stories, including the idea of relatively simple genetic causation of common, debilitating diseases. These incentives may have led to misleading predictions, which to some extent continue today. Although the Human Genome Project has facilitated biological research generally, the mis-promising of medical benefits, at least for treating common and debilitating disorders, could undermine support for scientific research over the long term.