Genetic testing company 23andMe is facing a class action lawsuit alleging that the Silicon Valley startup misled customers with advertising for its personalized DNA test kit. The test is marketed as a tool to help users predict their risk of developing various diseases. The lawsuit was filed in U.S. district court of California last week. It came days after the Food and Drug Administration ordered 23andMe to halt sales of its personalized test, saying the company has failed to show that the technology is supported by science. 23andMe sells its $99 test online. Customers receive a small tube in the mail, which they return to the company with a saliva sample for DNA analysis.