At least 415 gene variants now have different interpretations that could sway a medical decision, such as whether to have healthy breasts or ovaries removed to lower the risk of cancer, or to get a medical device such as an implanted defibrillator to cut the risk of sudden cardiac death.
"The magnitude of this problem is bigger than most people thought," said Michael Watson, executive director of the American College of Medical Genetics and Genomics, one of the study's authors and a partner in the data pooling project.
And it can harm patients. Rehm described a woman who had genetic testing and wrongly was told she did not have elevated risks for breast cancer. She later developed the disease but could have had preventive surgery had the right gene analyses been done.
The confusion of a staff member is measured by the length of his memos. -- New York Times, Jan. 20, 1981