Dr. Marion’s clinical and research interests include the natural history and genetic basis of multiple malformation syndromes, and recently, the genetic basis of autism spectrum disorders and inherited disorders of cardiac rhythm. The former chief of the Divisions of Genetic Medicine and Developmental Medicine and former director of genetics at Blythedale Children's Hospital, he was the founder of Montefiore’s Williams Syndrome Center, the Montefiore/Einstein Center for Cardiogenetics, and the Center for Congenital Disorders. He has published extensively in the medical literature in these areas, and, in addition, is the author of seven books including The Intern Blues, The Boy Who Felt No Pain (winner of a Christopher Award), Learning to Play God and Genetics Round: A Doctor’s Life in the Field that Revolutionized Medicine, which was published by Kaplan in October 2009.
His work as a clinician and medical educator has been widely recognized and he has been the recipient of numerous awards, including the Spirit of Achievement Award (presented by Einstein’s National Women’s Division), the Zella Bronfman Butler Change Agent Award (presented by the UJA/Federation of New York and the Butler Foundation), and Lifetime Teaching Awards from Einstein and Sarah Lawrence College.