Immunoglobulin A Deficiency 1

**Semantic type:** Disease or Syndrome

**Definition:** Decreased or absent levels of serum immunoglobulin A, with normal serum levels of immunoglobulin G and immunoglobulin M in a patient who is older than 4 years of age and in whom all other causes of hypogammaglobulinemia have been excluded. Affected individuals may be asymptomatic or have frequent infections, allergic reactions, or autoimmune disorders.

**Synonyms:** - IGAD1