Semaphorin 3d signaling defects are associated with anomalous pulmonary venous connections

Abnormalities in how pulmonary veins connect to the heart underlie a type of congenital heart disease. Jonathan Epstein and his colleagues show that this condition, termed anomalous pulmonary venous connections, can be caused by mutation of the gene encoding the guidance protein semaphorin 3d and show how this protein acts in the embryo to pattern the developing pulmonary veins.