Prenatal ductal thrombosis presenting as cyanotic heart lesion

We present a case of a late-preterm infant admitted for suspected cyanotic heart disease who was found to have a thrombosed ductus arteriosus. maternal history was significant for heterozygosity for factor v leiden, treated with enoxaparin during her pregnancy, and congenital hearing loss. the neonate did not have a factor v leiden mutation detected, but was found to have a heterozygous mutation within the mfthr gene. he was treated with anticoagulation, with improving hemodynamics measured by echocardiogram. this case presents a rare disease, which is potentially fatal if diagnosis is delayed.