[Familial occurrence of myelodysplastic syndrome concomitant with monoclonal gammapathy]

Myelodysplastic syndrome (MDS) combined with monoclonal gammopathy or multiple myeloma has rarely been reported. In this article, two siblings, a brother and his sister who showed simultaneous occurrence of MDS and monoclonal gammopathy are reported. The first case, a 73-year-old male, was admitted to our hospital in November, 1987. Analysis of peripheral blood revealed pancytopenia without blast cells. Bone marrow was hypocellular with 14.9% of myeloblasts and 2.8% of plasma cells characterized by 2 to 4 nuclei. Serum IgA level was 635 mg/dl and serum immunoelectrophoresis revealed a monoclonal IgA lambda band. The second case, a 70-year-old female, younger sister of the first case, was admitted to our hospital in January, 1988. Bone marrow was normocellular with 23% of peroxidase-negative myeloblasts and 12.8% of atypical plasma cells. Serum IgG level was 1,901 mg/dl with monoclonal IgG kappa band. Hematological findings have remained unchanged for 12 months. The first case was regarded as hypoplastic MDS with monoclonal gammopathy and the second case was MDS with smoldering myeloma. These cases were very similar with in respect to age, time of onset, clinical course, hematological findings and especially, association with M-protein. There are no reports concerning the familial incidence of MDS with M-protein. These findings supported the hypothesis that an initial event selects a clone of stem cells which retain the capability to differentiate into mature myeloid and lymphoid cells, in these cases B-cells.