Unfortunately the full exchange between 23andme and the FDA isn't public so we don't know what they FDA specifically asked from 23andme.
You know that you could have checked Google, right? X-/
There were 100 of emails going back and forth and dozens of face to face meetings over five years. Then the FDA said concluded that this isn't working and sent that letter.
Reading the letter it's interesting that the letter doesn't even forbid 23andMe from diagnosing people. It forbids them from marketing that they are diagnosing people.
The letter for example says:
...The Office of In Vitro Diagnostics and Radiological Health (OIR) has a long history of working with companies to help them come into compliance with the FD&C Act. Since July of 2009, we ha
This is prompted by Scott's excellent article, Meditations on Moloch.
I might caricature (grossly unfairly) his post like this: