IS case 522: Loeys-Dietz syndrome

Shandon Hatch, MD

University of Rochester

Imaging Sciences URMC 2010
Publication Date: 2010-09-10


Patient is a 2-year-old male with an aortic aneurysm.


Aortic aneurysm with or without dissection. Various heart, skeletal or brain defects depending on phenotype.


Loeys-Dietz syndrome


Loeys-Dietz syndrome is an autosomal dominant syndrome with aortic aneurysms as the dominant feature. It is similar to connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome. The disease is caused by heterozygous mutations in the genes encoding transforming growth factor beta (TGR-β) receptors. It was named after Dr. Bart Loeys and Dr. Harry Dietz, experts on Marfan syndrome, who characterized the genetic and physical features of the syndrome. The disease is characterized by aortic aneurysms that are prone to rupture and dissection. Hypertelorism with bifid uvula or cleft palate are common associated phenotypes. Other craniofacial and skeletal abnormalities such as craniosynostosis, malar hypoplasia, blue sclerae, joint laxity, arachnodactyly, and pectus deformity may be present.

This patient had a large descending aortic aneurysm with dissection. He also had a bileaflet aortic valve and enlarged aortic root. He had a genetics evaluation and was found to have hypertelorism, unilateral club foot, and arachnodactyly. He tested positive for a TGFBR2 mutation.


  1. Loeys BL, Schwarze U, Holm T, et al. Aneurysm syndromes caused by mutations in the TGF-beta receptor. N Engl J Med. 2006 Aug 24;355(8):788-98. PMID: 16928994

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