Arterial Tortuosity Syndrome (ATS)
What is Arterial Tortuosity syndrome?
Arterial Tortuosity Syndrome (ATS) is a rare connective tissue disorder that results from a defect in a glucose transporter in the cells. The defect in the glucose transporter 10 (GLUT10) results in a change in the transforming growth factor-ß (TGF- ß) pathway, which leads to abnormalities in the arterial wall. Disruption of the elastic fibers in the middle layer of the arterial wall results in tortuosity, elongation, stenosis and aneurysms in major arteries. Manifestations of ATS can include, but are not limited to, the following:
- Heart and major blood vessels
- Skeletal system
- Skin and soft tissues
Arterial Tortuosity syndrome has only been recently described, and only approximately 100 cases have been reported worldwide. So, it is uncertain how often it occurs.
What causes Arterial Tortuosity syndrome?
Arterial Tortuosity syndrome is caused by a defect in the SCL2A10 gene on chromosome 20, which encodes for glucose transporter 10 (GLUT10). It is thought that mutations in this gene cause decreased glucose to signal other proteins in the TGF-ß pathway. This pathway has been implicated in causing aneurysms in Marfan syndrome, Loeys-Dietz syndrome and some cutis laxa (loose skin) syndromes.
Arterial Tortuosity syndrome is inherited in an autosomal recessive pattern of inheritance. This mean that when a person has ATS, they have two mutated (altered) copies of the SCL2A10 gene. A person with ATS usually has unaffected parents who each carry a single copy of the mutated gene (and are referred to as carriers). Autosomal recessive disorders are typically not seen in every generation of an affected family. There is equal occurrence in males and females. When a couple has one child with ATS, their risk, per pregnancy of having another child with ATS, is 25%.
Why is Arterial Tortuosity syndrome a concern?
Children with ATS are at risk for serious problems involving the cardiovascular system, including the following:
- Arterial aneurysms. Weakening of the layers of the wall of the arteries, which leads to an increase in size. As the artery enlarges, the layers of the wall can separate (dissection), or tear completely through (rupture). Either of these conditions are life-threatening medical emergencies.
- Aortic aneurysms. Aneurysms of the aorta are common in Loeys-Dietz syndrome. The aorta is the large artery that carries blood out of the heart.
- Other arterial aneurysms. Aneurysms may occur in other arteries, such as those in the head and neck. Aneurysms in these areas can result in strokes.
- Arterial tortuosity. The arteries may become twisted, often looking like a corkscrew, which can compromise the arterial wall function.
What are the symptoms of Arterial Tortuosity syndrome?
Abnormal function of the glucose transporter 10 affects changes in TGF-ß. The change in TGF-ß creates the abnormalities in organs and body structures that may be seen with ATS. A large number of abnormalities can occur with the disorder and are listed below. Each child may experience symptoms differently. Symptoms may include:
Heart and blood vessels
- Enlargement of the aorta
- Tortuous arteries
- Tears in the aorta (aortic dissection)
- Stenosis of the arteries
- Aberrant (abnormal) origin of the arteries coming from the aorta
- Elongated face
- Macrocephaly (large head)
- Blepharophimosis (horizontal narrowing of the eye slits)
- Downslanting eyes
- “Beaked” nose
- Highly arched palate
- Micrognathia (small chin)
- Arachnodactyly (long fingers)
- Pectus deformities (chest wall pokes in or curves out)
- Joint hyperflexibility (subluxations may be recurrent)
- Joint contractures
- Scoliosis (curvature of the spine)
- Cutis laxa (loose skin)
- Soft of thin skin
- Diaphragmatic or hiatal hernia
- Bladder diverticuli
How is Arterial Tortuosity syndrome diagnosed?
In addition to a complete medical history and physical examination, your child's health care provider may complete a family medical history to look for other family members with known Arterial Tortuosity syndrome or some of the characteristics of the disease.
Other diagnostic tests for ATS may include the following:
- Electrocardiogram (ECG or EKG). A test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and detects heart muscle damage.
- Echocardiography (echo). A procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves.
- Magnetic Resonance Imaging (MRI). A procedure that evaluates the structure of the arteries of the body using high-powered magnets to produce pictures of the vessels, as well as the heart.
- X-ray. A diagnostic test that uses invisible X-ray beams to produce images of internal tissues, bones, and organs onto film.
- DNA studies. A blood sample sent to the genetics lab can analyze the SCL2A10 gene to determine whether a mutation is present.
Because enlargement of the aorta, or some of the other findings may become more obvious over time, in order to be diagnosed with ATS, DNA studies must show an abnormalitiy.
Treatment for Arterial Tortuosity syndrome
Currently, the only treatment that likely to improve life-expectancy in patients with ATS is surgery to repair aortic aneurysms before they tear. At the present time, there is no cure for the disorder. Treatment is based on which organ systems are affected and managing the problems that arise.
Long-term outlook for a child with Arterial Tortuosity syndrome
The natural history of aneurysm, dissection and stenosis in ATS is not well established but is of high concern. Some individuals present to medical care because of acute respiratory symptoms (caused by stenosis of pulmonary branches) or vascular dissection and for others, these findings are incidentally found upon imaging for other reasons. However, routine imaging follow-up including echocardiograms, MRAs or CTAs is recommended for all individuals diagnosed with ATS. This should be “tailored” to an individual depending on imaging findings and family history of aneurysm growth. Surgical intervention may be indicated.
Pulmonary artery stenosis may cause severe right ventricular hypertension and require surgical repair. The stenosis causes the right ventricle of the heart to pump harder and the muscle to become hypertrophied (larger).
There are successful reports of surgical intervention for ATS, for both aneurysms and stenosis in the aorta and arteries, including the pulmonary artery. Surgery often requires complex strategies that take into account the abnormal vascular anatomy.
Death in individuals with ATS has been attributed to heart failure secondary to pulmonary artery stenosis, pulmonary hypertension or systemic hypertension. Arterial rupture can also account for premature death.
Successful pregnancy with Cesarean delivery has been reported in ATS. Pregnancy is considered high-risk in patients with the disorder.
Online Medical Reviewer:
Last Review Date: 01/01/0001