Loeys-Dietz syndrome
Synonyms and keywords: Furlong's syndrome

# Overview
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). It is characterized by numerous site of aneurysms in the aorta (outpouchings in the weakened areas) in children . These aneurysms are more prone to rupture at a smaller diameter, putting the children at risk for major internal bleeding or dying if they are not detected and treated in a timely manner.

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

# Classification
- LDS type I - Presence of craniofacial involvement
- LDS type II - Absence of craniofacial involvement

# Pathophysiology
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
- 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.

# Diagnosis

## Symptoms
The main clinical characteristics include:
- Widely spaced eyes (orbital hypertelorism)
- Cleft palate or bifid uvula (a split in the tissue that hangs down in the back of the throat)
- Aortic and arterial aneurysms/dissections with tortuosity (corkscrew structure) of the arteries.

## Physical Examination

### Skin
- Translucency of the skin with velvety texture

### Bones and Joints
- Scoliosis
- 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

### Heart
- Murmurs:
Systolic ejection murmur: Bicuspid Aortic valves
Machinery murmur: Congenital heart problems including patent ductus arteriosus (connection between the aorta and the lung circulation)
Early or mid-diastolic murmur: atrial septal defect (connection between heart's atrial chambers)
- Systolic ejection murmur: Bicuspid Aortic valves
- Machinery murmur: Congenital heart problems including patent ductus arteriosus (connection between the aorta and the lung circulation)
- Early or mid-diastolic murmur: atrial septal defect (connection between heart's atrial chambers)

### Neurological examination
- Abnormal junction of the brain and medulla (Arnold-Chiari malformation)

# 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 Loeys-Dietz patients.

# 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guideline Recommendations: Evaluation and Management of Acute Thoracic Aortic Disease (DO NOT EDIT)

## Aortic Imaging in Genetic Syndromes (DO NOT EDIT)

## Genetic Syndromes of Familial Thoracic Aortic Aneurysms and Dissections (DO NOT EDIT) 
Treatment Guideline: