Loey's Dietz syndrome

Loeys-Dietz syndrome is a recently-discovered autosomal dominant genetic syndrome which has many features similar to Marfan syndrome, but which is caused by mutations in the genes encoding transforming growth factor beta receptor 1 (TGFBR1) or 2 (TGFBR2).^[1][2][3]

It was identified and characterized by American physician Harry C. Dietz and Belgian physician Bart L. Loeys, for whom it is named.

There are currently two forms of Loeys-Dietz syndrome which are further subdivided into another two forms based upon the genetic abnormality as shown in the table below:

• Congenital heart diseases including patent ductus arteriosus (connection between the aorta and the lung circulation) and atrial septal defect (connection between heart chambers)
• Abnormal junction of the brain and medulla (Arnold-Chiari malformation)
• Bicuspid aortic valves

Many of the physical findings typical in Loeys-Dietz syndrome are also found in Marfan syndrome cases, including increased risk of ascending aortic aneurysm and aortic dissection, abnormally long limbs and fingers, and dural ectasia (a gradual stretching and weakening of the dura mater that can cause abdominal and leg pain). However, it also has some additional traits not typical of Marfan patients, including widely spaced eyes, a split uvula in the back of the throat, and skin findings such as easy bruising or abnormal scars.

• Scoliosis

• Translucency of the skin with velvety texture

• Widely spaced eyes (orbital hypertelorism)
• Cleft palate or bifid uvula (a split in the tissue that hangs down in the back of the throat)

• Indented or protruding chest wall (pectus excavatum or pectus carinatum)

• Contractures of fingers and toes (camptodactyly)
• Long fingers and lax joints
• Club foot
• Premature fusion of the skull bones (craniosynostosis)
• Joint hypermobility

Aortic and arterial aneurysms/dissections with tortuosity (corkscrew structure) of the arteries.

As there is no known cure, Loeys-Dietz syndrome is a lifelong condition. Due to the high risk of death from aortic aneurysm rupture, patients should be followed closely to monitor aneurysm formation, which can then be corrected with vascular surgery.

Previous research in laboratory mice has suggested that the angiotensin II receptor antagonist losartan, which appears to block TGF-beta activity, can slow or halt the formation of aortic aneurysms in Marfan syndrome. A large clinical trial sponsored by the National Institutes of Health is currently underway to explore the use of losartan to prevent aneurysms in Marfan syndrome patients. Both Marfan syndrome and Loeys-Dietz syndrome are associated with increased TGF-beta signaling in the vessel wall. Therefore, losartan also holds promise for the treatment of Loeys-Dietz syndrome.

• List of cutaneous conditions

• Loeys-Dietz Syndrome Foundation
• orphan.net LDS-Syndrome
• GeneReview/NIH/UW entry on Loeys-Dietz Syndrome
• Loeys-Dietz Syndrome Canada

Categor:Cariology id:Sindrom Loeys-Dietz