[Multiple myeloma in siblings].

We encountered 2 patients with multiple myeloma in a family with 11 siblings, suggesting that the occurrence of the disease may be associated with genetic factors. Patient 1: The second daughter (age 79) was given a diagnosis of multiple myeloma and admitted to our hospital in December 1997 for treatment. IgG-lambda type M protein was detected by serum immunoelectrophoresis, punched out lesions (+) by X ray examination, and atypical plasma cells (14% of total) by bone marrow examination. Patient 2: The fifth daughter (age 68) received a diagnosis of multiple myeloma and was admitted to our hospital in May 1997 for treatment. Bence Jones-kappa type and IgA-kappa type M protein were detected by serum immunoelectrophoresis, punched out lesions (+) by X ray examination, and atypical plasma cells (90% of total) by bone marrow examination. It was noted that the sixth daughter had leukemia; hence, 3 of the 11 siblings had blood disorders. For this reason, HLA studies were performed and detected A31, B39, B51, and Cw7 in patient 1 and A31, B51, B62, and Cw4 in patient 2. Further case studies will hopefully reveal more details concerning the relationship between myeloma and HLA.