After working at Theranos Inc. for eight months, Tyler Shultz decided he had seen enough. On April 11, 2014, he emailed company founder Elizabeth Holmes to complain that Theranos had doctored research and ignored failed quality-control checks.

The reply was withering. Ms. Holmes forwarded the email to Theranos President Sunny Balwani, who belittled Mr. Shultz’s grasp of basic mathematics and his knowledge of laboratory science, and then took a swipe at his relationship with George Shultz, the former secretary of state and a Theranos director.

“The only reason I have taken so much time away from work to address this personally is because you are Mr. Shultz’s grandson,” wrote Mr. Balwani to his employee in an email, a copy of which was reviewed by The Wall Street Journal. Read More