By studying an animal model for persistent truncus arteriosus, he has learned that with this defect, the weakened heart muscle never works correctly. That's why we are trying to look at the genes responsible for the first heartbeat. Some key steps already are known in the process that initiates the heartbeat. PAX3 is a master gene that switches on other genes that give rise to the beating heart. One of these is a gene that enables calcium to enter heart cells.
Calcium comes into the heart cell, builds up and that cell contracts.
If a lot of cells contract in unison, that is the heartbeat. He thinks the culprit in persistent truncus arteriosus may be the genes expressed sometime after PAX 3 and before the calcium channel gene. In fact, the animals die in what is the human equivalent of the end of the first trimester. In humans, doctors believe that serious heart problems, such as persistent truncus arteriosus, may be a factor in up to 20 percent of spontaneous miscarriages and 10 percent of stillbirths. His goal is for persistent truncus arteriosus to be identified during the first trimester using sophisticated ultrasonography.