Pathology, Pathogens, and Genomics: towards value-free biology
February 22, 2011 Leave a comment
I was talking with Erin this weekend about how I didn’t agree with the rampant pathologizing of the human condition within medicine, particularly within the pharmaceutical industry. By this I mean I think it’s important to mind the line between description and normative declaration in medicine. Many ‘diseases’ (depression, scoliosis, cancer), were perhaps more precisely described as syndromes, or collections of syndromes. ‘Disease’ since the discovery of germs has implied a pathogenic agent. The pathogen of each of these examples (except for certain cases of cancer, as I’ll discuss below) has now been designated as the human body itself. This is the paradoxical result of an imprecise designation and a faulty logic.
Scoliosis might more traditionally be designated a deformity rather than a syndrome. But again this crosses the descriptive line into normative designation. Mutations (especially without mutagens such as radiation or viruses) are a critical component of each species’ genetic diversity. Mutations that are painful or debilitating can still acquire beneficial exaptive uses over time. A crucial feature of darwinian evolution is the expansion of the genomic substrate through the preservation of mutations, beneficial, neutral and deleterious. Exaptation (see Gould’s discussion of the concept) requires a broad substrate to effectively respond to different rules.
As mentioned above, there are cancers due to chemical or radioactive mutagens that differ from those I’m primarily indicating. Most cancers either involve a genome that produces malignantly reproducing cells or accumulated errors in DNA transcription or repair that generates the same. These mutations in DNA do not differ measurably from those that may produce beneficial hereditary effects (if they occur in gametes).
My overall assertion is that pathologizing aspects of the genome is tricky. Pathogens, mutagens, and parasites are entirely different cases than ‘diseases’ which are structural, so to speak. Even pathogens and parasites can develop a mutually beneficial symbiosis with their hosts. Pathologizing biology is also difficult. Senescence, for instance, could be viewed as a pathology, but has beneficially incorporated into numerous species. Individual dealth frees up resources for others of a species and can increase the genetic diversity of a deme by speeding up sexual reproduction.
None of this restricts the rights of patients or alleviates the obligations of doctors. The supposed need to identify what is ‘wrong’ is not a prerequisite to alleviating suffering, syndrome, disease, or otherwise.