Arterial tortuosity syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Arterial tortuosity syndrome is a disorder that affects connective tissue. Connective tissue provides strength and flexibility to structures throughout the body, including blood vessels, skin, joints, and the gastrointestinal tract.

As its name suggests, arterial tortuosity syndrome is characterized by blood vessel abnormalities, particularly abnormal twists and turns (tortuosity) of the blood vessels that carry blood from the heart to the rest of the body (the arteries). Tortuosity arises from abnormal elongation of the arteries; since the end points of the arteries are fixed, the extra length twists and curves. Other blood vessel abnormalities that may occur in this disorder include constriction (stenosis) and abnormal bulging (aneurysm) of vessels, as well as small clusters of enlarged blood vessels just under the skin (telangiectasia).

Complications resulting from the abnormal arteries can be life-threatening. Rupture of an aneurysm or sudden tearing (dissection) of the layers in an arterial wall can result in massive loss of blood from the circulatory system. Blockage of blood flow to vital organs such as the heart, lungs, or brain can lead to heart attacks, respiratory problems, and strokes. Stenosis of the arteries forces the heart to work harder to pump blood and may lead to heart failure. As a result of these complications, arterial tortuosity syndrome is often fatal in childhood, although some individuals with mild cases of the disorder live into adulthood.

Features of arterial tortuosity syndrome outside the circulatory system are caused by abnormal connective tissue in other parts of the body. These features include joints that are either loose and very flexible (hypermobile) or that have deformities limiting movement (contractures), and unusually soft and stretchable skin. Some affected individuals have long, slender fingers and toes (arachnodactyly); curvature of the spine (scoliosis); or a chest that is either sunken (pectus excavatum) or protruding (pectus carinatum). They may have protrusion of organs through gaps in muscles (hernias), elongation of the intestines, or pouches called diverticula in the intestinal walls.

People with arterial tortuosity syndrome often look older than their age and have distinctive facial features including a long, narrow face with droopy cheeks; eye openings that are narrowed (blepharophimosis) with outside corners that point downward (downslanting palpebral fissures); a beaked nose with soft cartilage; a high, arched roof of the mouth (palate); a small lower jaw (micrognathia); and large ears. The cornea, which is the clear front covering of the eye, may be cone-shaped and abnormally thin (keratoconus).

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Arterial tortuosity syndrome is caused by mutations in the SLC2A10 gene. This gene provides instructions for making a protein called GLUT10. The level of GLUT10 appears to be involved in the regulation of a process called the transforming growth factor-beta (TGF-β) signaling pathway. This pathway is involved in cell growth and division (proliferation) and the process by which cells mature to carry out special functions (differentiation). The TGF-β signaling pathway is also involved in bone and blood vessel development and the formation of the extracellular matrix, an intricate lattice of proteins and other molecules that forms in the spaces between cells and defines the structure and properties of connective tissues.

SLC2A10 gene mutations that cause arterial tortuosity syndrome reduce or eliminate GLUT10 function. By mechanisms that are not well understood, a lack (deficiency) of functional GLUT10 protein leads to overactivity (upregulation) of TGF-β signaling. Excessive growth signaling results in elongation of the arteries, leading to tortuosity. Overactive TGF-β signaling also interferes with normal formation of the connective tissues in other parts of the body, leading to the additional signs and symptoms of arterial tortuosity syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Arterial tortuosity syndrome is a rare disorder; its prevalence is unknown. About 100 cases have been reported in the medical literature.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormality of the carotid arteries · Very frequent (99-80%)

Any structural abnormality of the carotid arteries, including the common carotid artery and its' arterial branches.

Aortic aneurysm · Very frequent (99-80%)

Aortic dilatation refers to a dimension that is greater than the 95th percentile for the normal person age, sex and body size. In contrast, an aneurysm is defined as a localized dilation of the aorta that is more than 150 percent of predicted (ratio of observed to expected diameter 1.5 or more). Aneurysm should be distinguished from ectasia, which represents a diffuse dilation of the aorta less than 50 percent of normal aorta diameter.

Aortic root aneurysm · Very frequent (99-80%)

An abnormal localized widening (dilatation) of the aortic root.

Arterial stenosis · Very frequent (99-80%)

Narrowing or constriction of the inner surface (lumen) of an artery.

Congestive heart failure · Very frequent (99-80%)

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

Dilatation · Very frequent (99-80%)

An abnormal increase in the diameter of an artery or vein, either as a diffuse dilatation or as a localized, sac-like outpouching of the vessel wall (aneurysm).

Telangiectasia of the skin · Very frequent (99-80%)

Presence of small, permanently dilated blood vessels near the surface of the skin, visible as small focal red lesions.

Abnormal zygomatic bone morphology · Frequent (79-30%)

An abnormality of the zygomatic bone.

Other findings in the same source

From: Orphanet

Additional reported features include Aortic dissection (Frequent (79-30%)); Craniosynostosis (Frequent (79-30%)); Fatigue (Frequent (79-30%)); Femoral hernia (Frequent (79-30%)); Hyperextensible skin (Frequent (79-30%)); Hypertelorism (Frequent (79-30%)); Inguinal hernia (Frequent (79-30%)); Joint hypermobility (Frequent (79-30%)); Long face (Frequent (79-30%)); Macrotia (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Arterial tortuosity syndrome is Vascular Medicine, with a vascular specialist / vascular surgeon as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which part of the circulation needs assessment?
• What changes in pain, swelling, colour or limb function require prompt reassessment?
• Would observation, a medical approach or a procedure be considered in this case?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Arterial tortuosity syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.