In the early 1950’s, a 66-year-old woman, sick with colon cancer, received a blood transfusion. Then, unexpectedly, she suffered a severe rejection of the transfused blood. Reporting on her case, the French medical journal Revue D’Hématologie identified her as, simply, “Patient Vel.” After a previous transfusion, it turns out, Mrs. Vel had developed a potent antibody against some unknown molecule found on the red blood cells of most people in the world—but not found on her own red blood cells. But what was this molecule? Nobody could find it. A blood mystery began, and, from her case, a new blood type, “Vel-negative,” was described in 1952. Soon it was discovered that Mrs. Vel was not alone. Though rare, it is estimated now that over 200,000 people in Europe and a similar number in North America are Vel-negative, about 1 in 2,500. For these people, successive blood transfusions could easily turn to kidney failure and death. So, for sixty years, doctors and researchers have hunted—unsuccessfully—for the underlying cause of this blood type. But now a team of scientists from the University of Vermont (UVM) and France has found the missing molecule—a tiny protein called SMIM1—and the mystery is solved. Reporting in the journal EMBO Molecular Medicine, UVM’s Dr. Bryan Ballif, Dr. Lionel Arnaud of the French National Institute of Blood Transfusion, and their colleagues explain how they uncovered the biochemical and genetic basis of Vel-negative blood. “Our findings promise to provide immediate assistance to health-care professionals should they encounter this rare but vexing blood type,” says Dr. Ballif. The pre-publication results were presented online on March 18, 2013, and the finalized report will be published, as an open-access article, in the next edition of the journal. Last year, Drs.Login Or Register To Read Full Story