Mayo Clinic Researchers Discover Genetic Glitch in Heart's Electrical System That Leads to Drowning.

(From AScribe)

ROCHESTER, Minn. -- Mayo Clinic researchers have identified defects in a second gene called RyR2 that causes malfunctions in the heart's electrical system and contributes to what were previously unexplained drownings.

Mayo researchers first discovered defects in a gene that causes the heart's electrical system to malfunction and described how it might cause a drowning of an otherwise healthy person and reported their findings in a study published in the New England Journal of Medicine in 1999. The newest findings are described in the current issue of Mayo Clinic Proceedings.

In the newest study, Mayo researchers conducted sleuthlike molecular autopsies or postmortem genetic testing on coroners' cases of unexplained and unexpected drownings that were referred to the Sudden Death Genomics Laboratory at Mayo Clinic in Rochester, Minn.

"Harnessing the power from the Human Genome Project, our research team has solved these inexplicable tragedies through direct genetic evidence," says Michael Ackerman, M.D., Ph.D., director of the Sudden Death Genomics Laboratory at Mayo Clinic in Rochester. "Swimming and genetic glitches in the heart's electrical system appear to be a bad combination, but we need further study to understand why and how this occurs."

In the Mayo Clinic Proceedings article, two cases were studied by Mayo Clinic researchers in which both individuals were proficient swimmers. A teenage girl died at swim team practice, after being found floating facedown in the swimming pool. She had just finished swimming four laps. Efforts to resuscitate her were unsuccessful. Another case involved a young boy who failed to surface immediately after diving in the water at a lake. Efforts to resuscitate him also were unsuccessful.

Akin to the investigators on the television show Crime Scene Investigation, senior research technologist David Tester is one of Dr. Ackerman's lead sudden death investigators who cracked the code and pinpointed the critical misspelling in the 3 billion base pair genetic code for these drowning victims.