What are the other Names for this Condition? (Also known as/Synonyms)

• SAVI Syndrome
• TMEM173-AID

What is STING-Associated Vasculopathy with Onset in Infancy? (Definition/Background Information)

• STING-Associated Vasculopathy with Onset in Infancy (SAVI) is a genetic disorder that affects the blood vessels and causes inflammation and damage to the skin and internal organs. It is a rare disorder that affects young children, with most cases being diagnosed during infancy
• SAVI Syndrome is passed on with autosomal dominant inheritance. It is caused by mutations in the STING gene, which provides instructions for making a protein that helps the body respond to viral infections and cancer. The mutations lead to the overactivation of the protein, resulting in the associated signs and symptoms
• The signs and symptoms of STING-Associated Vasculopathy with Onset in Infancy vary depending on the severity of the disorder and the organs affected. Common symptoms include skin rashes and blisters, ulcers on the skin and mucous membranes, difficulty breathing, abdominal pain, high fever, among others
• STING-Associated Vasculopathy with Onset in Infancy is diagnosed through a combination of clinical examination, blood tests, imaging studies, and genetic testing. A biopsy of affected tissue may also be performed to confirm the diagnosis. If left untreated, it may result in complications that include organ damage, loss of mobility, scarring and disfigurement
• The treatment focuses on controlling inflammation and preventing organ damage through steroids, immunosuppressants, and supportive care to manage the symptoms. Presently, there are no available measures to prevent STING-Associated Vasculopathy with Onset in Infancy as it is a genetic disorder
• The prognosis of STING-Associated Vasculopathy with Onset in Infancy depends on its severity and the organs affected and can vary from one individual to another. Some individuals may have better outcomes with adequate treatment, while others may have severe organ damage and lifelong disability

Who gets STING-Associated Vasculopathy with Onset in Infancy? (Age and Sex Distribution)

• STING-Associated Vasculopathy with Onset in Infancy is an extremely rare disorder that affects infants and young children; most cases are diagnosed in the first year of life
• It is estimated to occur in 1 in every 10 million births
• The disorder affects males and females equally
• The ethnic/racial groups specifically affected are as yet unknown

What are the Risk Factors for STING-Associated Vasculopathy with Onset in Infancy? (Predisposing Factors)

• The risk factors for STING-Associated Vasculopathy with Onset in Infancy include a positive family history of the disorder or other mutations involving the TMTM173 gene

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of STING-Associated Vasculopathy with Onset in Infancy? (Etiology)

STING-Associated Vasculopathy with Onset in Infancy (SAVI) is caused by mutations in the STMEM173 gene, which provides instructions for making the STING protein that helps the body respond to viral infections and cancer. 

• SAVI Syndrome is characterized by the activation of the STING protein, which plays a critical role in the immune system’s response to viral infections and cancer. The mutations lead to the protein overactivation, causing inflammation and damage to the blood vessels and internal organs
• The disorder is inherited in an autosomal dominant manner

Note: STING is an acronym for STimulator of INterferon Genes or ST IN G.

Autosomal dominant mode of inheritance: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of STING-Associated Vasculopathy with Onset in Infancy?

The signs and symptoms of STING-Associated Vasculopathy with Onset in Infancy vary depending on the severity of the disorder and the organs affected. The common symptoms include:

• Skin rashes and blisters
• Ulcers on the skin and mucous membranes
• Swelling and inflammation of the hands and feet
• Difficulty breathing
• Abdominal pain
• Vomiting and diarrhea
• High fever
• Fatigue
• Anemia

How is STING-Associated Vasculopathy with Onset in Infancy Diagnosed?

• STING-Associated Vasculopathy with Onset in Infancy is diagnosed through a combination of the following:
  • Clinical examination and medical history evaluation
  • Assessment of one’s signs and symptoms
  • Blood tests
  • Imaging studies
  • Genetic testing
• A biopsy of affected tissue(s) may also be performed to confirm the diagnosis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of STING-Associated Vasculopathy with Onset in Infancy?

The complications of STING-Associated Vasculopathy with Onset in Infancy may include:

• Organ damage, particularly involving the lung
• Chronic inflammation
• Loss of mobility
• Scarring and disfigurement
• Gangrene of fingertips leading to auto-amputation or surgical amputation

How is STING-Associated Vasculopathy with Onset in Infancy Treated?

• The treatment for STING-Associated Vasculopathy with Onset in Infancy focuses on controlling inflammation and preventing organ damage
• This may include:
  • Steroids to reduce inflammation
  • Immunosuppressants to suppress the immune system
  • Antibiotics to prevent infections
  • Supportive care to manage symptoms

How can STING-Associated Vasculopathy with Onset in Infancy be Prevented?

• Currently, it is not possible to prevent STING-Associated Vasculopathy with Onset in Infancy (SAVI) as it is a genetic disorder
• Families with a history of SAVI Syndrome may be offered genetic counseling

What is the Prognosis of STING-Associated Vasculopathy with Onset in Infancy? (Outcomes/Resolutions)

• The prognosis for STING-Associated Vasculopathy with Onset in Infancy varies depending on the severity of the disorder and the organs affected
• Some individuals may have a good outcome with proper treatment, while others may have severe organ damage and lifelong disability.

Additional and Relevant Useful Information for STING-Associated Vasculopathy with Onset in Infancy:

The following link is a useful resource for further information on rare diseases and disorders:

https://www.dovemed.com/diseases-conditions/rare-disorders/