Abstract
Loeys-Dietz syndrome is a rare autosomal dominant connective tissue disorder with a genetic predisposition to aneurysm formation and congenital cardiofacial defects through genetic mutation affecting the transforming growth factor-beta (TGFβ) signaling pathway. We present a case of a 6-year-old female patient with Loeys-Dietz syndrome who developed an annular aortic valve abscess and ascending aortic dissection due to Staphylococcus aureus endocarditis. Within this case, multiple complications from Loeys-Dietz syndrome were identified, including prosthetic valve infection, aneurysm formation and dissection, septic embolism, and aspiration pneumonia. The clinical presentation, pathologic findings, and pathophysiology will be discussed.