Inclusion Criteria:

RC patients enrolled in this study are to meet the following

Inclusion Criteria:

- RC Patients with hypocellular BM normal karyotype included in the EWOG-MDS 2006
protocol who receive SCT from a MFD or a compatible (8/8) or one allelic mismatch UD

- Written informed consent by the caretakers and whenever possible the patient's
assent.

- Age less than 18 years The caretakers will have given their written informed consent
to participate in the study. Consent will be documented by the caretaker's dated
signature which will be also signed and dated by the investigator in the
participating center. If the patient is able to understand the meaning and
consequences of the study and its procedures his/her written informed assent is also
needed. Written informed consent has to be obtained prior to enrollment into the
study.

Exclusion Criteria:

Patients who do not fulfill the Inclusion Criteria may not be included into study.
Specific Exclusion Criteria are:

•Transplanted with a preparative regimen other than thiotepa, fludarabine