Loeys-Dietz Syndrome (cont.)

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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In this Article

• What is Loeys-Dietz syndrome?
• What are the signs and symptoms of Loeys-Dietz syndrome?
• Is Loeys-Dietz syndrome inherited?
• What causes Loeys-Dietz syndrome?
• How is Loeys-Dietz syndrome diagnosed?
• How is Loeys-Dietz syndrome treated?
• Loeys-Dietz At A Glance
• Loeys-Dietz Syndrome Index

Loeys-Dietz syndrome is inherited, meaning that it is a genetic syndrome that tends to run in families. The mutated abnormal gene that causes Loeys-Dietz syndrome is dominant, and only one parent needs pass the gene to a child in order for the syndrome to develop. (This is in contrast to recessive syndromes in which each parent must pass the gene to a child in order for the syndrome to develop.) A report published in the New England Journal of Medicine in August, 2006, reported that 52 affected families (with a total of 90 affected individuals) had been identified.

The cause of Loeys-Dietz syndrome has been determined recently. TGF-beta is a signaling molecule produced in the body that influences the growth, movement, and activity of cells as well as the death of cells by changing the way many genes within the cells are expressed. TGF-beta brings about the changes within cells by binding to receptors on the surfaces of the cells. . Loeys-Dietz syndrome is known to be a result of mutations in the TGF-beta-receptor I (TGFBR1) or II (TGFBR2) genes. The genetic mutations in Loeys-Dietz causes a change in the receptor that prevents TGF-beta from working on the cells. A test is available that can detect the genetic mutation associated with the syndrome; however, the test is not available in most laboratories.

The diagnosis of aortic aneurysms, including those seen in the Loeys-Dietz syndrome, usually is made by injecting a dye that is visible by X-ray, computerized tomography (CT), or magnetic resonance imaging (MRI) into the blood vessels. X-rays or scans by CT or MRI then are done that show the arteries and aneurysms (because the aneurysms are filled with dye-containing blood). Although aortic aneurysms are the hallmark of Loeys-Dietz Syndrome and the characteristic facial features may suggest the diagnosis, the definitive diagnosis of Loeys-Dietz Syndrome can only be established by the genetic test (described above).