IgG deficiency is believed to be connected to genetic factors, although the exact cause for it is unknown, according to Johns Hopkins Medicine. IgG deficiency may also be related to having a deficiency of other immunoglobulins.
IgG deficiency typically presents in patients with relatives who have either IgG deficiency or common variable immunodeficiency, states the National Institutes of Health. IgG deficiency also occurs in people with family members who have diseases such as diabetes mellitus and systemic lupus erythematosus. However, some cases of IgG deficiency are the result of gene deletion. Additionally, a person with a deficiency of immunoglobulin's A and M has an increased likelihood of having a deficiency of immunoglobulin G, explains Johns Hopkins Medicine.
IgG deficiency occurs as a result of the body’s inability to produce an adequate amount, and increases a person’s risk of contracting illnesses such as respiratory, ear and sinus infections, reports Johns Hopkins Medicine. Having an IgG deficiency also increases the risk of getting pneumonia, bronchitis and, in some cases, lethal infections.
Appropriate treatment for IgG deficiency depends upon the severity of the illness, states John Hopkins Medicine. Some infections can be treated with the regular use of antibiotics. However, in some cases of IgG deficiency, a person may need to improve his immune function with immunoglobulin replacement therapy.