Familial immunopathies: report of nine families and survey of literature.

Nineteen individuals are reported who represent nine familial instances of various immunopathies. Multiple myeloma was diagnosed in 10 members of five families, lanthanic (idiopathic) paraproteinemia in five members of two families and either myeloma or lanthanic paraproteinemia in four members of the remaining two families. The parent-child relationship occurred in three instances, siblings were affected in three, and first cousins in three families. Immunochemical studies revealed IgG paraprotein in nine cases; IgA in three; IgMl type in three subjects belonging to the same family; Bence-Jones protein in one case and biclonal paraproteinemia, IgGk plus IgAl in one. Three individual cases of lanthanic paraproteinemia, discovered in a prospective study of 76 relatives of subjects with immunopathies, suggest that there may be a higher frequency of immunopathies among family members than observed in the general population of comparable age. The published reports on familial paraproteinemias are reviewed..