Normally, a newborn's immunoglobulins come from the mother during pregnancy and wane after birth until 3-6 months of age, when the infant begins to start to produce their own IgG. However, in<unk> , the IgG synthesis is delayed, and the<unk>  is prolonged beyond age 6 months.
Transient hypogammaglobulinemia of infancy
Selective immunoglobulin A deficiency
Adult-onset immunodeficiency syndrome
X-linked agammaglobulinemia
Primary immunodeficiency
Isolated primary immunoglobulin M deficiency
Combined immunodeficiencies
Severe combined immunodeficiency