header
 

Myelodsyplastic syndrome (MDS)Profile

EGR1 -5 / del 5q, CEP 7 -7/del 7q31, +8, del 20q12

F MDS

Test Synonym:

Myelodsyplastic syndrome

Associations:

Myelodsyplasia

CPT Code:

88367x6 – Morphometric analysis, in situ hybridization, automated
88368x6 – Morphometric analysis, in situ hybridization, manual

Turnaround Time:

3 days

Methodology:

Fluorescence in situ Hybridization (FISH)

Specimen Requirements:

  • 2.0 ml (min. 1.0 ml) peripheral blood in sodium heparin preferred, EDTA accepted
  • 1.0 ml (min. 0.5 ml) bone marrow in sodium heparin preferred, EDTA accepted
  • 5 mm3 fresh tissue in MPLN RPMI media
  • 3.0 ml (min. 2.0ml) FNA in MPLN RPMI media
  • 10% neutral buffered formalin fixed paraffin embedded tissue

    • Causes for Rejection:

    Clotted specimen; specimens exposed to extreme temperature; anticoagulant toxic to cells; insufficient number of cells; improper fixative

    Specimen Stability:

  • Peripheral blood and bone marrow stable at 18-25°C for 72 hours
  • Fresh tissue or FNA stable at 2-8°C for 72 hours

    • Storage and Handling:

    • Whole blood and bone marrow ship ambient

    • Fresh tissue, FNA or paraffin embedded tissue ship in a Styrofoam container with an ice pack (do not allow ice pack to directly contact sample)

    Reference Range:

    See report

    Indication:

    Myelodysplastic syndrome (MDS) refers to a group of clonal disorders characterized by trilineage defects in hematopoiesis, including the erythrocytic, granulocytic, and megakaryocytic lineages. It is sometimes considered a premalignant condition that often progresses to acute myeloid leukemia (AML) when additional genetic abnormalities are acquired. MDS often develops following autologous bone marrow transplantation, affecting 20% of patients with non-Hodgkin lymphomas who received bone marrow transplants.

    Clonal chromosomal abnormalities are observed in bone marrow cells from 30% to 50% of de novo MDS cases and 80% of secondary MDS patients. Common cytogenetic abnormalities in MDS include loss of chromosome 7 or partial deletions of chromosome arms 5q, 20q, 11q, or 7q. Deletion of chromosome 5 is the most common structural abnormality in MDS and AML. The CEP 8 probe detects trisomy 8, the most common numerical abnormality in MDS and AML.

    Complex karyotypes involving 3 or more of these chromosomes occur in approximately 5% of cases and will also be detected by this panel of probes.  Detection of abnormalities involving 5, 7, 8, and 20 are important prognostic indicators in MDS and AML.  In general, patients with complex karyotypes and abnormalities of chromosome 7 have a poor prognosis compared to patients with a normal karyotype or with deletions of chromosome 5 or 20 occurring as isolated chromosome changes. FISH for these chromosome abnormalities can be performed on interphase or metaphase cells.

    FISH can detect these abnormalities in either interphase or metaphase cells.

    References:

    1. Look A.T. (2005) Molecular Pathogenesis of MDS. Hematology 1:156

    2. Hofmann WK et al (1996). Myelodysplastic syndromes: clinical features. Semin Hematol 33(3):177

    3. Flandrin G: Classification of myelodysplastic syndromes. Atlas Genet Cytogenet Oncol Haematol. May 2002