+ Low risk myelodysplastic syndrome (refractory anemia) diagnosed 32 months before (December, 2009).

-

-

76 yrs

F

-

-

-

-

2.7

8.5

146

0

5 Global normocellularity, with erythroid and megakaryocytic hyperplasia and megakaryocytic dysplasia (no-lobated megakaryocytes suggestive of 5q- Syndrome), less than 5% of myeloblasts and 23% of ring sideroblasts.

Myelodysplastic Syndrome - Refractory anemia with ring sideroblasts (FAB classification).

Myelodysplastic Syndrome - Refractory citopenia with multilineage dysplasia and ringed sideroblasts (WHO classification).

08-2012

Erythropoietin

-

-

-

A

09-2012

1 month from the cytogenetic abnormality detection, 30 months from the MDS diagnosis.

Bone marrow

24 and 48 hours without stimulating agents

GTG

46,XX,del(5)(q13q31)[1]/46,X,t(X;20)(q13;q13.3),del(5(q13q31))[11]/46,XX[8]

not done

The band Xq13 is frequently involved in rearrangements seen in hematological malignancy. The structural rearrangement idic(X)(q13) is associate with the myelodysplastic syndrome with ringed sideroblasts and this region is difficult for mapping because is rich in complex repeats with subregional inversions and high concentration of LINE repeats (boosters of X-inactivation). The chromosome 20q interstitial deletions are well established nonrandom abnormalities in myeloid disorders, particularly in polycythemia vera and myelodysplasia. Very few cases of translocations involving chromosome 20 have been reported in hematological malignancy. The band 20q13 is rich in cancer genes and translocation involving this region has been reported in cases of acute myeloid leukemia. One study shows that breakpoints of X chromosomes associated with myelodysplasia were located in a region of 450 kb next to the gene XIST (Xq13). Another study demonstrated that a critical event in myelodysplasia is loss of tumor suppressor genes present on the long arm of chromosome 20. This suppression can occur when a potential cryptic deletion is associated with a translocation. This phenomenon generates a second mechanism causing inactivation of the X chromosome and derivative 20 resulting loss of function of tumor suppressor genes. Seven cases of t(X;20)(q13;q13) were described in literature; all affecting women over the age of 57 with myeloid disorders. We report the detection, by conventional cytogenetic methods, the t(X;20)(q13;q13.3) in one female patient with myelodysplastic syndrome subtype Refractory citopenia with multilineage dysplasia and ringed sideroblasts (classification WHO). Although this translocation was described as a primary clonal chromosome abnormality, in this case the t(X;20) seems to be a secondary chromosome abnormality following a deletion 5q.