split uvula, and skin findings such as easy bruising or abnormal scars may distinguish Loeys–Dietz from Marfan syndrome. Affected individuals often develop immune system related problems such as allergies to food, asthma, hay fever, and inflammatory disorders such as eczema or inflammatory bowel disease. Findings of Loeys–Dietz syndrome may include: Skeletal/spinal malformations: craniosynostosis, Scoliosis, spinal instability and spondylolisthesis, Kyphosis Sternal abnormalities: pectus excavatum, pectus carinatum Contractures of fingers and toes (camptodactyly) Long fingers and lax joints Weakened or missing eye muscles (strabismus) Club foot Premature fusion of the skull bones (craniosynostosis) Joint hypermobility Congenital heart problems including patent ductus arteriosus (connection between the aorta and the lung circulation) and atrial septal defect (connection between heart chambers) Translucency of the skin with velvety texture Abnormal junction of the brain and medulla (Arnold–Chiari malformation) Bicuspid aortic valves Criss-crossed pulmonary arteries Cause Types (old nomenclature) Several genetic causes of Loeys–Dietz syndrome have been identified. A de novo mutation in TGFB3, a ligand of the TGF β pathway, was identified in an individual with a syndrome presenting partially overlapping symptoms with Marfan Syndrome and Loeys–Dietz Syndrome. Diagnosis Diagnosis involves consideration of physical features and genetic testing. Presence of split uvula is a differentiating characteristic from Marfan Syndrome, as well as the severity of the heart defects. Loeys–Dietz Syndrome patients have more severe heart involvement and it is advised that they be treated for enlarged aorta earlier due to the increased risk of early rupture in Loeys–Dietz patients. Because different people express different combinations of symptoms and the syndrome was first identified in 2005, many doctors may not be aware of its existence. Treatment 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. In those patients in which