Hypergammaglobulinemia is a medical condition with elevated levels of gamma globulin

Gamma globulin

Gamma globulins are a class of globulins, identified by their position after serum protein electrophoresis. The most significant gamma globulins are immunoglobulins , more commonly known as antibodies, although some Igs are not gamma globulins, and some gamma globulins are not Igs.-Use as medical...

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It is a type of immunoproliferative disorder.
Hypergammaglobulinemia is a condition that is characterized by the increased levels of a certain immunoglobulin in the blood serum. The name of the disorder refers to the position of the excess of proteins after serum protein electrophoresis (found in the gammaglobulin region).

Most hypergammaglobulinemias are caused by an excess of immunoglobulin M (IgM), because this is the default immunoglobulin type prior to class switching.