a 78-year - old woman presented with weakness , fatigue and hemoglobin of 8.3 g / dl , to another clinic in september , 2009 , and she was given erythrocyte suspension replacement . she had regression in her existing complaints with blood replacement therapy , but after one month , same complaints reappeared with a low hemoglobin value and she was referred for further investigation to the outpatient clinic of hematology of our university faculty of medicine . her hematologic parameters ar that time were as follows : white blood cell count of 6390/mm , neutrophils 3785/mm , hemoglobin 8.1 g / dl , mean corpuscular volume ( mcv ) 95 fl , and platelets 211.000/mm . with the provisional diagnosis of myelodysplastic syndrome due to an isolated anemia unrelated to nutritional status , bone marrow aspiration biopsy was performed . her bone marrow aspiration showed normal cellularity ; and biopsy revealed increase in the number of megakaryocytes , signs of dismegakaryopoiesis , minimal dysplasia in erythroid series , and normal morphology in myeloid series . upon conventional cytogenetical studies she had been lost - to - follow up for approximately a year and during that time she had received a total of 4 units of erythrocyte suspension , and erythropoietin treatment was started . however , erythropoietin treatment discontinued because she did not respond to the maximum dose of 10.000 iu three times a week . she did not attend to her follow - up visits regularly and in the mean time she had transfusions monthly at another clinic . since her transfusion dependency increased , she was considered for lenalidomide treatment in april , 2013 . after 10 days of treatment , her liver enzymes increased more than 3 times of normal values and she had thrombocytopenia ( platelet count : 38.000/mm ) then her treatment was postponed for two weeks she restarted lenalidomide treatment at daily doses of 5 mg after liver enzymes and platelet counts returned to normal . during further follow - up , increase in liver enzymes and severe thrombocytopenia were not detected ; her hemoglobin value increased and transfusion dependency was not observed ( figure 1 ) . in myelodysplastic syndrome , interstitial deletion in the long arm of chromosome 5 is a common cytogenetical abnormality seen in 16 - 28% of the patients . it is characterized by hypoproliferative anemia and normal megakaryocytes with hypolobated nuclei or increased dysplastic megakaryocytes in bone marrow [ 7 , 8 ] . most of the patients are transfusion - dependent because endogen erythropoietin production is usually increased . one of the major problems during the progression of the disease in transfusion - dependent mds patients is the iron overload secondary to transfusion and the dependency for chelation therapy to treat iron overload . the immunomodulatory drug lenalidomide that has additional benefits in the regulation of erythropoiesis , inhibition of angiogenesis , and reorganization of erythroid production , targets the mds clone directly [ 9 , 10 ] . this syndrome is rarely seen ; therefore , there is not enough data about isolated 5q - syndrome as well as lenalidomide therapy in our country . isolated 5q - syndrome presents with normal or increased thrombocyte counts in peripheral blood and anemia with frequent transfusion replacement dependency . in clinical studies lenalidomide provided long term blood transfusion independency and erythroid response in patients with low- risk del(5q ) and without del(5q ) . in a phase ii study of low- risk del(5q ) patients ; after 24 weeks , evaluation of erythrocyte response showed that 67% of the patients with 5q deletion who were treated with lenalidomide became transfusion independent . in low- risk 5q deletion mds patients , daily doses of 10 mg for 21 days are used , and repeated with 28 day - intervals that can be modified if needed . in order to evaluate the response , adverse events can be easily overcome with dose modifications . in clinical studies , thrombocytopenia and leukopenia are frequently observed but these adverse reactions usually appear during the first 8 weeks of treatment . therefore , weekly clinical follow - up at the beginning of the therapy is recommended . less often adverse events of fatigue , rash and diarrhea can be noted . in conclusion , in isolated 5q - syndrome which is a mds subgroup and characterized by transfusion dependency ; lenalidomide can decrease transfusion dependency with a tolerable adverse event profile that can be overcome with dose modifications . assessment of all prevalent cases in our country will be helpful to reveal the efficacy and adverse event profile of lenalidomide .
5q - syndrome is a special subgroup of myelodysplastic syndrome in terms of follow - up and treatment . 
 lenalidomide is an immunomodulatory drug that is frequently used in the treatment of multiple myeloma . 
 some clinical studies have shown that lenalidomide treatment is effective in 5q syndrome and significantly decreases the transfusion dependency in these patients . in this paper 
 , we would like to share a dramatic response of lowered transfusion dependency after treatment with low - dose lenalidomide in a patient who received myelodysplastic syndrome diagnosis and isolated 5q anomaly in our clinic .