Wiktionary
dysgammaglobulinemia
n. An immune disorder characterized by a reduction in some (but not all) types of gamma globulins.
Wikipedia
Dysgammaglobulinemia
Dysgammaglobulinemia is a type of immune disorder characterized by a reduction in some types of gamma globulins.
It is distinguished from hypogammaglobulinemia, which is a reduction in all types of gamma globulins.
Hyper IgM syndrome can be considered a form of dysgammaglobulinemia, because it results from a failure of transformation from IgM production to production of other antibodies, and so the condition can be interpreted as a reduction of the other types.