Daniel MacArthur points out that 23andMe seems to be testing people for rare variants associated with Parkinson's disease and he wonders why those results (the company noted recently that it hasn't found anyone with those variations) haven't been reported back to the customers. He's guessing that they are concerned about the reliability of the results. "Screening for extremely rare variants is tricky for two reasons: firstly, since there are very few individuals around who carry the mutation, obtaining positive controls is difficult; and secondly, screening accuracy needs to be extremely high to keep down the rate of false positives," he writes. He adds that this is a sign that 23andMe is interested in moving into the clinical arena.
In other personal genomics news, if you've been suspecting you have warrior ancestry, Warrior Roots would be glad to take your money (if you're male, that is -- the test looks at the Y chromosome) and tell you what warrior clan you come from.