“The results of this study hopefully will bring researchers closer to determining the genetic causes of BPD and may have important implications for treatment programs in the future,” said Timothy Trull, professor of psychology in the MU College of Arts and Science. “Localizing and identifying the genes that influence the development of BPD will not only be important for scientific purposes, but will also have clinical implications.”

First, it’s important to point out IMO that research based on genetic linkage analysis has never produced a therapy for any illness, whether that illness be a simple genetic disease (ie one mutated gene causes the disease) like Huntington disease or cystic fibrosis, or something more complex (ie many genes plus the environment are involved), like cancer. All modern treatments and even ongoing cutting edge clinical research for these diseases, are based on other molecular biological studies, not linkage analysis.

Second, the only medical use of the results of genetic linkage studies so far is to identify and diagnose people. Most of the time, such “genetic testing” can only indicate a probability of having a disease (with the exception of simple genetic diseases).

Third, diagnosing people in the absence of a treatment has questionable value. Historically it’s pretty much always been problematic and often morally questionable–in the early 20th century, people were diagnosed as “feeble-minded” and put into institutions. Typically the one thing they did have in common is that they were poor or non-white. This practice (called eugenics–the use of biology to segregate people deemed genetically unfit) continued in some form until the 1940s.

Modern diagnosis for untreatable conditions is typically performed in the prenatal setting with the goal of terminating the pregnancy. In terms of parental choice and abortion rights I personally believe that this is fair and helpful, but I want to point out that it is not what anybody would consider a medical treatment to help somebody with a disease. So the article’s argument that genetic linkage studies “may have important implications for treatment programs in the future” (and there have been thousands of such news articles saying exactly the same thing) is completely unsupportable, IMO, by any past or current evidence.

Nature vs. Nurture?