<unk>  (SIgAD) is the most common primary immunodeficiency and is defined as "serum level of IgA equal or below 7mg/dl in the presence of normal level of other<unk> s in individuals older than four years of age and in which other causes of hypogammaglobulinemia have been excluded". The first cases with<unk>  were diagnosed in 1963-64, 10 years after<unk>  A was described in the serum by Graber and Williams. SIgAD is more prevalent in caucasians. It is classified based on either the laboratory values of B-cells subsets or the clinical phenotype of individuals with the condition. SIgAD has been attributed to an intrinsic B cell lymphocyte defect, T cell lymphocyte abnormalities and most recently an impairment in cytokine regulation indicating that it is a heterogenous dysfunction but the exact mechanism is still not clear. SIgAD may be genetically transferred but the inheritance pattern is variable. Several studies have reported SIgAD linkage with MHC and non MHC susceptibility genes that are also found in many autoimmune conditions which somewhat explains their association. Majority of patients with SIgAD are asymptomatic. Symptomatic patients may present with Infections such otitis media, sinopulmonary infections, gastrointestinal infections, allergies or autoimmune conditions. Diagnosis is usually based on serum level of<unk>  A. There is no specific treatment for<unk>  but there are several components of its management to prevent the progression and complications such as patient education, vaccination, use of antibiotics and<unk> s. The prognosis is generally very good but few cases may progress to common variable immunodeficiency that doesn't predict a favorable outcome.
Selective immunoglobulin A deficiency
Immunoglobulin M deficiency
Primary immunodeficiency
Hyper-IgE syndrome
IgG deficiency
X-linked agammaglobulinemia
Transient hypogammaglobulinemia of infancy
Combined immunodeficiency