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

• Adenosine Deaminase 2 Deficiency Disorder
• Childhood-Onset Polyarteritis Nodosa
• Sneddon Syndrome

What is Deficiency of Adenosine Deaminase 2? (Definition/Background Information)

• Deficiency of Adenosine Deaminase 2 (DADA2) is a rare genetic disorder that affects the immune system. It is caused by a mutation in the ADA2 gene and results in a lack of the enzyme adenosine deaminase 2 (ADA2)
• This leads to abnormal maturation in some immune system cells, causing generalized inflammation and damage to blood vessels. This disorder is typically diagnosed in early childhood and can cause a wide range of signs and symptoms, including fever, skin rashes, muscle weakness, joint pain, and recurrent infections
• Deficiency of Adenosine Deaminase 2 is inherited in an autosomal recessive pattern. The risk factors include having a family history of DADA2 and inheriting two copies of the mutated ADA2 gene, one from each parent, that results in development of the disorder
• Deficiency of Adenosine Deaminase 2 is typically diagnosed based on a combination of clinical examination, genetic testing, and blood tests to measure the levels of ADA2 enzyme. The treatment typically includes immunosuppressive medications to reduce inflammation and prevent blood vessel damage, including antibiotics to prevent and treat infections
• The prognosis varies depending on the severity of Deficiency of Adenosine Deaminase 2 and treatment effectiveness. With proper treatment, most patients can have an improved quality of life. The disorder can lead to progressive organ damage, and cause disabilities and functional limitations if left untreated

Who gets Deficiency of Adenosine Deaminase 2? (Age and Sex Distribution)

• Deficiency of Adenosine Deaminase 2 is a rare disorder that is manifested at birth (congenitally)
• The disorder affects both males and females

What are the Risk Factors for Deficiency of Adenosine Deaminase 2? (Predisposing Factors)

The risk factors for Deficiency of Adenosine Deaminase 2 include:

• Having a family history of the disorder
• Inheriting two copies of the mutated ADA2 gene, one from each parent, resulting in development of the disorder

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 Deficiency of Adenosine Deaminase 2? (Etiology)

• Deficiency of Adenosine Deaminase 2 is caused by mutations in the ADA2 gene, leading to a lack of the enzyme adenosine deaminase 2 (ADA2)
• It results in abnormal maturation in certain immune system cells, causing generalized inflammation and damage to blood vessels
• The disorder is inherited in an autosomal recessive manner

Autosomal recessive mode of inheritance: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Deficiency of Adenosine Deaminase 2?

The most common signs and symptoms of Deficiency of Adenosine Deaminase 2 include:

• Recurrent fever
• Skin rashes
• Recurrent infections
• Inflammation and damage to blood vessels
• Fatigue, muscle weakness, and joint pain

How is Deficiency of Adenosine Deaminase 2 Diagnosed?

Deficiency of Adenosine Deaminase 2 is typically diagnosed based on a combination of the following:

• Clinical examination and medical history evaluation
• Assessment of the presenting signs and symptoms
• Tests to measure the levels of ADA2 enzyme
• Imaging studies
• Genetic testing

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 Deficiency of Adenosine Deaminase 2?

The complications of Deficiency of Adenosine Deaminase 2 may include:

• Fatigue, muscle weakness, and joint pain
• Progressive organ damage

How is Deficiency of Adenosine Deaminase 2 Treated?

A treatment for Deficiency of Adenosine Deaminase 2 may typically include:

• Immunosuppressive drugs to reduce inflammation and prevent damage to blood vessels
• Antibiotics to prevent and treat infections

How can Deficiency of Adenosine Deaminase 2 be Prevented?

• Currently, there are no known methods to prevent Deficiency of Adenosine Deaminase 2 as the cause is a genetic mutation
• Genetic counselling and testing may be recommended for individuals with a family history of the disorder and for couples planning to have children

What is the Prognosis of Deficiency of Adenosine Deaminase 2? (Outcomes/Resolutions)

The prognosis for Deficiency of Adenosine Deaminase 2 (DADA2) varies depending on the severity of the disorder and the effectiveness of the treatment. 

• With proper treatment, most patients with DADA2 can have a good quality of life.
• However, the disorder can cause disabilities and functional limitations if left untreated

Additional and Relevant Useful Information for Deficiency of Adenosine Deaminase 2:

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

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