Analyses of red cell membrane proteins and red cell morphology in50 patients with myelodysplastic syndrome *
I hypothesize that, in part, the hemolysis in myelodysplastic syndrome（MDS） is the result of membrane protein disorders. I evaluated erythrocyte membrane protein and the shape of erythrocytes in 50 cases of MDS. All 50 MDS cases exhibited some changes in erythrocyte shape. Almost all of the cases（90%） had multiple changes in erythrocyte shape. There were nine cases（18%） with membrane protein disorders. Three of these nine cases showed a partial band 3 deficiency, one case showed a partial P4.1 deficiency, three cases showed a partial P4.2 deficiency, and two cases showed a partial band 7 deficiency. The shape of erythrocytes in the cases with a partial deficiency of band 3 and P4.1 was the same as that encountered in congenital erythrocyte membrane protein disorders. When we checked the band 3 gene of the three cases with band 3 partial deficiency, one case had a missense mutation that was supposed to be pathogenic. Some previous studies have reported the presence of elliptocytosis in some MDS cases with del（20q）. When we checked the chromosome, eight cases had del（20q）, and six of these eight（75%） showed elliptocytosis. However, 24 out of 38 cases（63.2%） without del（20q） also showed elliptocytosis. Therefore, it is suggested that del（20q） may not affect erythrocyte shape. (Accepted on October 29, 2008)
