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

• C2D Disorder 

What is Complement Component 2 Deficiency Disorder? (Definition/Background Information)

• Complement Component 2 Deficiency (C2D) Disorder is a genetic condition that affects the immune system
• Signs and symptoms include recurrent bacterial infections and risk for a variety of autoimmune conditions
• Infections can be very serious and are common in early life. They become less frequent during the teen and adult years
• The most frequent autoimmune conditions associated with C2D Disorder are lupus (10-20%) and vasculitis
• Complement Component 2 Deficiency Disorder is caused by mutations in the C2 gene and is inherited in an autosomal recessive fashion

(Source: Complement Component 2 Deficiency Disorder; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Complement Component 2 Deficiency Disorder? (Age and Sex Distribution)

• Complement Component 2 Deficiency Disorder is a rare disorder
• The presentation of symptoms may occur during childhood (usually), or later infrequently in teenage or adulthood
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Complement Component 2 Deficiency Disorder? (Predisposing Factors)

• A positive family history may be an important risk factor, since Complement Component 2 Deficiency Disorder can be inherited

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 Complement Component 2 Deficiency Disorder? (Etiology)

• The most frequent autoimmune conditions associated with C2D Disorder are lupus (10-20%) and vasculitis

(Source: Complement Component 2 Deficiency Disorder; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Autosomal recessive: 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 Complement Component 2 Deficiency Disorder?

The signs and symptoms of Syndromic Complement Component 2 Deficiency Disorder may include:

• Purpura
• Bacterial infections
• Associations with the following autoimmune conditions may be noted
  • Systemic lupus erythematosus (SLE) in 10-20% of the cases
  • Vasculitis

(Source: Complement Component 2 Deficiency Disorder; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Complement Component 2 Deficiency Disorder Diagnosed?

Complement Component 2 Deficiency Disorder is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

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 Complement Component 2 Deficiency Disorder?

The complications of Complement Component 2 Deficiency Disorder may include:

• Recurrent infections
• Severe infections

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Complement Component 2 Deficiency Disorder Treated?

There is no cure for Complement Component 2 Deficiency Disorder, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complications that develops.

How can Complement Component 2 Deficiency Disorder be Prevented?

Currently, Complement Component 2 Deficiency Disorder may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Complement Component 2 Deficiency Disorder? (Outcomes/Resolutions) 

• The prognosis of Complement Component 2 Deficiency Disorder is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Complement Component 2 Deficiency Disorder:

The following DoveMed website link is a useful resource for additional information:

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