Mr. C's doctors became suspicious that they had the wrong diagnosis when he showed nearly no significant signs of the disorder in later life, according to the full report and decision from Martin, the public services ombudsman.
"We are deeply sorry for the anxiety and distress caused to Mr. C and his family and we would like to publicly apologize to them," Melanie Hornett, nurse director of Lothian National Health Service, said in a statement. "This was an exceptional case and we have accepted and implemented the recommendations of the report to to prevent a repeat of a similar incident."
The incident may be a rare one but, Martin said, it has spurred the National Health System that serves Edinburgh to have a solid policy on genetic testing.
"It shouldn't be down to the individual to know that science has moved on, it should be down to the health care provider to let them know," Martin said. "Their clinical choice was impacting his life."
Indeed, Mr. C's false diagnosis also limited his financial decisions. Mr. C couldn't get life insurance because of his diagnosis and therefore couldn't get a decent mortgage, Martin said.
Until 2008, with the passage of the Genetic Information Nondiscrimination Act (GINA), people diagnosed with Huntington's in the United States would face even more challenges than Mr. C. Before GINA, people in the United States with Huntington's disease found it nearly impossible to buy their own health insurance. They also had no protection from being fired because of their genetic mutation, said Joan Scott, director of the Genetics and Public Policy Center at Johns Hopkins University in Baltimore.
"Those concerns are why people with Huntington's disease have wanted to remain anonymous," said Fred Taubman of the Huntington's Disease Society of America.
And for privacy reasons, as well as psychological ones, Taubman said, very few people who know Huntington's runs in the family decide to get genetic testing.
Taubman said the National Institutes of Health estimates that 10,000 Americans have symptomatic Huntington's disease and another 250,000 are at risk for having the gene.
"Our best estimate is that probably less than 7 percent of people who know they're at risk actually go for the testing," he said. "Very low percentage."
Johns Hopkins' Scott, who is also a certified genetic counselor, said doctors take the emotional impact of testing for such devastating mutations quite seriously.
But "there's no consensus really in the U.S. in how to deal with potentially re-contacting individuals if a new and better test becomes available."