Loeys-Dietz Syndrome

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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Loeys-Dietz syndrome is a recently-described connective tissue disorder with features similar to those of Marfan syndrome, and the vascular type of Ehlers-Danlos syndrome. Loeys-Dietz syndrome is primarily characterized by aortic aneurysms (weakened outpouchings of the aorta, the main artery in the body) in children. In Loeys-Dietz syndrome, the aortic aneurysms are prone to rupture at a smaller size than other aneurysms, putting children with Loeys-Dietz at great risk for dying if the aneurysm is not identified and treated early.

The syndrome is named for pediatric geneticist Harry Dietz, director of the William S. Smilow Center for Marfan Syndrome Research at Johns Hopkins University and his colleague, Bart Loeys, who characterized the genetic and physical markers of the syndrome together with Dr. Dietz.

Aortic aneurysms and abnormal organization of blood vessels (widespread tortuosity of the arteries in locations other than the aorta) are the hallmarks of Loeys-Dietz syndrome, but many affected children have characteristic physical and facial features that may be the first abnormality to be recognized. Recently, LDS has been subdivided into two types, LDS type I (LDSI) and type II (LDSII), signaling the presence or the absence of cranio-facial involvement, respectively.

The craniofacial characteristics of Loeys-Dietz syndrome include early fusion of the skull bones (known as craniosynostosis), widely spaced eyes (hypertelorism), and cleft palate or split uvula. In some individuals with Loeys-Dietz syndrome, other physical abnormalities have been noted, including defects at birth in the heart and brain, osteoporosis (weak bones), skin changes (such as translucent skin and/or easy bruising), and defects of the spine or chest. It is important to note that the severity of the visible physical characteristics varies widely among affected individuals, but the danger of rupture of aneurysms remains the same no matter how severe or mild the physical characteristics are.

In many cases pediatricians may be able to recognize the characteristic facial features of Loeys-Dietz syndrome, and on this basis suggest further evaluation for the presence of aortic aneurysms and vascular irregularities. Other people with the syndrome are recognized when they seek medical assistance for other reasons, such as heart murmurs or a family history of Marfan syndrome or another condition that may cause aortic aneurysms.