The investigators' primary objective is to study prevalences of myocardial iron overload, defined as a cardiac T2*< 20 ms, in 3 populations of multiply transfused patients, affected with thalassemia, sickle cell disease, and myelodysplasia.

The inevestigators' primary objective is to study prevalences of myocardial iron overload, defined as a cardiac T2*< 20 ms, in 3 populations of multiply transfused patients, affected with thalassemia, sickle cell disease, and myelodysplasia.

The investigators will record concomitantly parameters which, according to literature data, may influence the occurrence of this complication, and will look for correlations with these parameters and iron overload (secondary objectives), in each of the 3 cohorts.

14 centres are involved and enrol patients with thalassemia, or sickle cell disease, or myelodysplasia having received in the past year > 8 erythrocyte concentrates, and having had a cardiac MRI. Patients files register the type of the disease, age at the beginning of transfusion and chelation, chelator type and dosage, liver and cardiac T2*.

Inclusion Criteria:

• Thalassemia, sickle cell disease, myelodysplasia
• having received in the past year > 8 erythrocyte concentrates
• > 6 years of age

Exclusion Criteria:

• preexisting cardiac disease

patients affected with thalassemia, SCD, and myelodysplasia