DNA sequencing is increasingly becoming the go-to test to uncover the causes of rare genetic disorders, writes Gina Kolata at the New York Times. While parents seeking such a test for their children have high expectations, experts note that genetic mutations are only found in about a quarter of cases, and the test leads to better treatment plans in only about 3 percent of cases and improvement in about 1 percent of cases. "We give the impression that we can do these things because we only publish our successes," William Gahl from the National Institutes of Health says. He adds that, when seeing patients, "we try to make expectations realistic."
"It seems this is a floor in terms of the results outcome for these children, as some of them may receive better or more effective treatments in the future, because the specific nature of their disease is already known," Razib Khan at the Gene Expression blog notes. "Since most medical treatments today are marginal in effect these outcomes don't surprise or depress me, and the price point is sure to come down."
Kolata also points out that having a diagnosis can also help patients and their families access special education services as well as ease the medical claims process.