Working at Columbia with Dr. Merritt, the preeminent academic neurologist of the day, influenced Dr. Duvoisin to what would fast become a passion for knowledge about Parkinson’s disease. While there, Dr. Duvoisin contributed to the discovery of the role that vitamin B6 plays in reversing the benefits of L-dopa therapy. He also became intrigued by observations of three patients, each of whom had an identical twin who was unaffected by the disease. This suggested that Parkinson’s is not inherited. Dr. Duvoisin continued to pursue additional studies of twins with Parkinson’s when, as full professor, he moved to Mount Sinai School of Medicine in 1973. Many Unanswered Questions about Parkinson’s A s of then, there was no consensus about the cause of Parkinson’s disease. Some felt it was the result of a variety of viruses. Others believed it was caused by environmental toxins. One theory proposed that Parkinson’s was an epidemic and would disappear eventually. When Dr. Duvoisin was approached by the National Institutes of Health (NIH) to join with Roswell Eldridge, MD, on an additional twin study, his insatiable curiosity and need for answers fueled the partnership. He and Dr. Eldridge collected and studied 65 pairs of identical twins, each with a single affected individual. The results, however, were inconclusive. The answer to the great riddle that was Parkinson’s was as elusive as ever. But Dr. Duvoisin was not deterred. Although genetics was not Dr. Duvoisin’s field of study, he had publicly lobbied the belief that Parkinson’s disease was not inherited. Nevertheless, when he began to see more patients who had other family members with the disease, he realized that he needed to continue pursuing the possibility of a genetic involvement. By the time he was appointed chair, Department of Neurology, at Rutgers Medical School in 1979, Dr. Duvoisin was on a mission with a single focus. In 1990, he hired Alice Lazzarini, PhD, clinical assistant professor of neurology, to become part of the newly endowed William Dow Lovett Center for Neurogenetics team. She remembers clearly the challenge Dr. Duvoisin posed to her: “Alice, I want you to prove that Parkinson’s disease is genetic.” Lawrence Golbe, MD, professor of neurology, was Dr. Duvoisin’s junior colleague. Together, the team set an agenda. 20 Robert Wood Johnson I MEDICINE