Loeys-Dietz Syndrome (LDS)

Loeys-Dietz syndrome (LDS) is a disorder that affects the connective tissues of the body and increases the patient's risk of aneurysms in arteries such as the aorta. This condition is rare and was only recently identified as a condition in 2005. Because the condition is relatively recent, some physicians may not be aware of it and may not properly diagnose patients.

There are four types of LDS, labeled as types 1 to 4, and they are distinguished by their genetic cause.

Symptoms

LDS can vary in severity, and symptoms can become apparent in either adulthood or during childhood. The main symptom of the condition is an enlarged aorta. The aorta is the largest artery in the body. It rises from the heart's left ventricle (the major chamber that pumps blood out of the heart) and is filled with oxygen-rich blood that travels throughout the body. The aorta itself goes from the heart, through the diaphragm, and into the abdomen. Many smaller vessels branch off from it. These branches bring blood to the kidneys and organs of the digestive system. The aorta divides into the iliac arteries, a pair of arteries that branch off into each leg.

Enlargement can cause the aorta to weaken, which can result in additional symptoms such as:

Aneurysms and dissection can occur in other areas of the body, but in patients with LDS they are most commonly found in the aorta.

Other symptoms of LDS can include skeletal abnormalities such as:

  • Premature fusion of the skull bones (craniosynostosis)
  • Abnormal side-to-side curvature of the spine (scoliosis)
  • Sunken chest (pectus excavatum)
  • Protruding chest (pectus carinatum)
  • Inward- and upward-turning foot (clubfoot)
  • Flat feet (pes planus)
  • Elongated limbs with joint deformities called contractures that restrict the movement of certain joints
  • Disc degeneration
  • Joint inflammation (osteoarthritis) in the knees and the joints of the hands, wrists and spine

Additional symptoms of the condition include:

  • Bruising easily
  • Abnormal scarring after an injury
  • Translucent skin, with veins often visible beneath the skin
  • Stretch marks
  • Widely spaced eyes (hypertelorism)
  • Split in the soft flap of tissue that hangs from the back of the mouth (bifid uvula)
  • Opening in the roof of the mouth (cleft palate)
  • Food allergies
  • Asthma
  • Inflammatory disorders


Causes and Risk Factors

LDS is caused by a genetic mutation that can occur in one of four different genes depending on the type of LDS the patient has.

Diagnosis

Diagnosis of LDS is usually based on finding an enlarged aorta and getting the results of genetic testing. The physician may perform a physical examination to determine if the patient has other symptoms associated with LDS, and also examine the family medical history of the patient to see if there is LDS in the family. In many cases, the condition is identified when the patient is undergoing diagnosis of an aneurysm.

Imaging tests such as an MRI, CT scan or chest X-ray may be used to see if the aorta is enlarged or to determine if an aneurysm is present. If more detail is needed about the heart and its arteries, angiography may be used. This procedure provides a map of the heart and the blood vessels near it by injecting a special dye into the blood vessels that shows up on the X-rays. Echocardiography may also be used to create a moving picture of the heart while it works.

Treatments

Because LDS is genetic, there is no cure. Treatment for LDS will focus on reducing stress to the aorta and other arteries, managing skeletal and muscular difficulties and any pain associated with them, and managing immune system responses such as allergies.

For aneurysms associated with the condition, treatment will depend on the size of the aneurysm and will focus on keeping it from rupturing. For smaller aneurysms, observation and monitoring may be the best course of treatment. This will include an echocardiogram every six months and possible medication if the patient has high blood pressure or high cholesterol levels. This may include beta blockers to slow the heartbeat and to relax the heart muscle so that it can work more efficiently. Angiotensin II receptor blockers may also be prescribed to lower blood pressure.

In some cases, such as if the aneurysm is larger, surgery may be needed. The type of surgery performed will depend on the location of the aneurysm and the patient's overall health. Open chest surgery repairs the area weakened by the aneurysm by replacing it with a graft made of a synthetic tube. A timely operation should be performed in affected patients, as LDS represent one of the most aggressive connective-tissue disorders, frequently requiring lifesaving aortic operations in patients in their teens.

The knowledgeable and highly trained staff at the Cedars-Sinai Heart Institute will work with each patient to determine the best treatment option.