What is Arterial Tortuosity Syndrome?
Arterial Tortuosity Syndrome is a very rare type of disorder of connective tissues that are one of the major components of a human body. Connective tissues form several organs like vessels, joints, skeleton, and skin. They are characterized by their property of the presence in the cells consisted of the network of the extracellular matrix of many types of proteins, sugars. The complicated network of molecules provides the tissues with the strength they require and form. It also ensures the passage of factors and nutrients which control and are responsible for proliferation and the growth of cells.
Arteries are referred to as the blood vessels which carry oxygen-rich blood away from the heart. Arteries throughout the body get distorted, twisted and lengthened in the body of the person who is experiencing Arterial Tortuosity Syndrome. The arteries which are affected by the disorder are very vulnerable and may develop bulges on the walls of arteries which look alike balloons, known as aneurysms. It may tear the arteries; this condition is known as dissection. The syndrome can also cause the arteries to get narrow, known as stenosis. Aorta is the main artery in the human body and carries blood from the heart and throughout the body. Hence, if this artery is affected by Arterial Tortuosity Syndrome, the whole body can be affected. Narrowing of the pulmonary artery is a common condition in people who suffer from the syndrome.
During early childhood or infancy, the life-threatening situation can be faced by affected the child.
Population Affected by Arterial Tortuosity Syndrome
Both males and females are affected by Arterial Tortuosity Syndrome in equal numbers. Cases around 100 have already been reported. Finding the exact rate of prevalence and incidence is very difficult and is unknown until now. As most of the individuals who are affected by the disease have been misdiagnosed or left untreated, it is very difficult to find the exact number of people in the general population who have been affected with the Arterial Tortuosity Syndrome. It generally begins in early childhood or infancy.
Causes of Arterial Tortuosity Syndrome
A mutation in the gene named SLC2A10 is the main cause of Arterial Tortuosity Syndrome. The function of genes includes providing instructions to the body for creating proteins as they play a very crucial role in most of the functions of the body. When the genes get altered, the protein produced by the body can be not efficient, faulty, or may be absent. Due to this, many functions of many organs of the body may get hampered, depending on the function of the protein. This can have a very serious problem in the body and it may also affect the functioning of the brain.
There are 23 different types of mutations or alterations identified in the SLC2A10. SLC2A10 mutations can be inherited as an autosomal recessive trait. When abnormal genes are inherited by a person for the same trait from each of the parents, the condition caused is known as Recessive Genetic Disorder. There are also conditions in which a person receives an abnormal and normal gene. In this condition, the person gets the Arterial Tortuosity Syndrome but doesn’t reflect the symptoms.
There is a 25% risk in each pregnancy that the child is affected when there is a chance that both the carrier parents may pass the defective gene to the child. There is a 50% chance that the child will be a carrier like his/her parents. And there is only 25% of chance that the child doesn’t get any abnormal gene from the parents and is genetically normal for the particular trait. The chances of risks are the same in males and females.
A protein called Facilitative Glucose Transporter 10 (also known as GLU10) is created by the SLC2A10 gene. The function of the gene is to regulate the transport of dehydroascorbic acid or DAA (it is the oxidized form of Vitamin C) and sugar throughout the cellular membrane. The low levels of the protein GLU10 are caused by the mutations or alterations of SLC2A10 genes in patients suffering from Arterial Tortuosity Syndrome.
Signs and Symptoms of Arterial Tortuosity Syndrome
Arachnodactyly: It is also known as achromatic. Arachnodactyly is a condition in which the toes and fingers are slim and long abnormally as compared to the arch of the foot or the palm of the hand. The person may also have his/her thumbs pulled inwards towards the palm. It may be present in the child at the time of birth or can be caused later in the life of an individual.
Keratoconus: It is a type of eye disorder in which an individual faces the progressive thinning of the cornea. It can lead to sensitivity from light, blurred vision, nearsightedness, double vision or astigmatism. In most of the cases, both the eyes of the person are affected. In serious cases, a circle may appear within the cornea.
Aortic Insufficiency: It is also known as aortic regurgitation. It is a state in which the aortic valve of the heart starts leaking leading the reverse flow of the blood during ventricular diastole, into the left ventricle from the aorta valve. Due to this, the cardiac muscles are forced to work harder than they usually have to do.
Blepharophimosis: It is a type of congenital condition. The characteristic of blepharophimosis is the horizontally narrowed palpebral fissure. Blepharophimosis syndrome is a disorder of which blepharophimosis is a part of. It is also called as epicanthus inversus syndrome or ptosis syndrome. In this condition, the person suffering from it faces bilateral ptosis with reduced size of the lid, both vertically and horizontally. The vertical and horizontal eyelid openings or palpebral fissures are shortened. The eyes get more spaced and widely apart than they normally are and should be the condition is also called as the telecanthus. The two types of blepharophimosis are known as type 1 and type 2.
*The symptoms and signs of the Arterial Tortuosity Syndrome may vary from person to person.
Diagnosis of Arterial Tortuosity Syndrome
The diagnosis of Arterial Tortuosity Syndrome can usually be done with genetic testing as the main cause of the syndrome is the mutation of a gene called SLC2A10. The diagnosis may be followed by the following tests:
- Physical Exam (may vary according to the symptoms and from person to person)
- MRI Test
- CT Scan
*The doctor treating the patient may advise some more test according to his/her condition, health, symptoms, and signs, etc.
Treatment of Arterial Tortuosity Syndrome
The treatment a person may need to cure the Arterial Tortuosity Syndrome may vary according to the symptoms he/she is facing. All the specialists have to coordinate in order to treat the person. The specialists may include surgeons, neurologists, dermatologists, ophthalmologists, cardiologists, and other specialists also. The team of specialists has to coordinate with each other in order to plan the patient’s treatment comprehensively and systematically. Genetic counseling may be beneficial for the patient and his/her family to tackle the situations well.
According to the medical science, usually many complications are not faced by the patient during or after cardiovascular surgery. The risk of fatal incidents is very similar to the general population.
There are also other treatments available to treat the syndrome. They are supportive and symptomatic and may consist of surgeries to treat the conditions of intestinal diverticula, skeletal malformations, or hernia.
The follow-up of the treatment may include the ECG (electrocardiography) and other tests also to evaluate the condition of the person and take the next steps accordingly.
The prognosis of Arterial Tortuosity Syndrome has about a 12% mortality rate.
Arterial Tortuosity Syndrome is a disorder of connective tissues. Connective tissues form several organs like vessels, joints, skeleton, and skin. So, disorders related to the connective tissues can cause serious damage to a person’s body. Arteries throughout the body get distorted, twisted and lengthened in the body of the person who is experiencing Arterial Tortuosity Syndrome.
The signs and symptoms of Arterial Tortuosity Syndrome may vary from person to person. Some of the common symptoms among the patients of ATS include mental dysfunction, keratoconus, arachnodactyly, and blepharophimosis.
The main cause of the Arterial Tortuosity Syndrome is the mutation of the gene called SLC2A10. This gene instructs the body to create the protein. So, alteration in this gene can cause defects in the protein produced by the body and many organs may start to malfunction, including the brain.
The diagnosis may include several tests depending on the condition of the patient. Some of the tests are MRI scan, CT scan, and ECG test.
- Moceri, P., Albuisson, J., Saint-Faust, M., Casagrande, F., Giuliano, F., & Devos, C. et al. Arterial Tortuosity Syndrome. Journal Of The American College Of Cardiology, (2013). 783. doi: 10.1016/j.jacc.2012.06.070
- Ritelli, M., Drera, B., Vicchio, M., Puppini, G., Biban, P., & Pilati, M. et al. Arterial tortuosity syndrome in two Italian paediatric patients. Orphanet Journal Of Rare Diseases, (2009). 20. doi: 10.1186/1750-1172-4-20