Primary amyloidosis (AL) in families.

We report the occurrence of immunoglobulin-related amyloidosis (AL) in three separate families, each family having two members affected. None of the six patients had evidence to suggest the presence of familial amyloidosis (AF). Previously, immunoglobulin-related amyloidosis (AL) was considered to be a sporadic disease process. Because of the occasional familial occurrence of other monoclonal gammopathies such as monoclonal gammopathy of undetermined significance, multiple myeloma, and macroglobulinemia of Waldenström, amyloidosis (AL) should be added to the list of immunopathies with a familial predisposition.