5q- Syndrome

5q- Syndrome

Case 00-2

History/Physical Findings:

Patient is a 70 year old woman with a history of macrocytic anemia and thrombocytosis.

Physical Findings:

Physical exam was unremarkable with no evidence of lymphadenopathy or splenomegaly.

Laboratory Findings:

Peripheral Blood:

WBC

3.3 x 109/L

Neutrophils

42.8%

RBC

2.18 x 1012/L

Lymphocytes -

44.2%

HGB

81 g/L

Monocytes

4.8%

Hct

23.3 L/L

Eosinophils

5.9%

MCV

106.5 fL

Basophils

2.2%

MCH

37.1 pg

 

 

MCHC

348 g/L

 

 

RDW

16.2

 

 

PLT

589 x109/L

 

 

B12

2020 pg/mL (nl: 251-911 pg/mL)

Red Cell Folate

770.6 pg/mL (nl: >130 pg/mL )

Ferritin

182 ng/mL (nl: 9-204 ng/mL)

Bone Marrow Biopsy --

       00-02-3 00-02-2

Microscopic examination at 200X and 400X maginification demonstrates a normocellular marrow. There are numerous small megakaryocytes with hypolobated nuclei.

Cytogenetics --

00-02-1

Cytogenetic analysis reveals loss of a portion of the long arm of chromosome 5.

 


Diagnosis:

 

The findings of macrocytic anemia, thrombocytosis, numerous small hypolobated seen on bone marrow biopsy, and deletion of long arm of chromosome 5 are diagnostic of 5q- Syndrome. 

 


Discussion:

 

5q- Syndrome is classified as a myelodysplastic syndrome, and is generally associated with a good prognosis. This hematologic disorder is characterized by refractory anemia with a chromosome 5q deletion as the sole karyotypic abnormality of the bone marrow. 5q- syndrome is found predominantly in elderly women and consists of macrocytic anemia, thrombocytosis (50% of patients), erythroblastopenia and megakaryocyte hyperplasia with nuclear hypolobation. Most patients have a stable clinical course but are often transfusion dependent. Very few of these patients transform to an acute leukemia. Although the specific molecular abnormalities in 5q- myeloid disorders are unknown, inactivation of one or more genes in the 5q31q33 segment is critical. This 5q31q33 region includes the genes for the macrophage colony-stimulating factor-1 receptor (CSFIR), secreted protein, acidic, cysteine-rich (SPARC), and glutamate receptor (GR1A1). This region, critical to the 5q- syndrome, appears to be distinct from the other 5q regions associated with MDS and myeloid leukemia.


 

References:

  1. Practical Diagnosis of Hematologic Disorders, 3rd ed. Kjeldsberg, Carl, et al. 2000.

  2. Lewis S, et al: Hematological features of patients with myelodysplastic syndromes associated with a chromosome 5q deletion. American Journal of Hematology. 49:194-200, 1995.

  3. Jaju RJ, et al: Molecular cytogenetic delineation of the critical deleted region in the 5q- syndrome. Genes, Chomosomes and Cancer 22:251-256, 1998.

  4. Boultwood J et al: Transcription mapping of the 5q- syndrome critical region: cloning of two novel genes and sequencing, expression, and mapping of a further six novel cDNAs. Genomics 66(1):26-34, 2000.

Contributors:

James R. Mize, M.D.
Department of Pathology
University of Virginia Health Sciences Center

Donald J. Innes, Jr., M.D.
Department of Pathology
University of Virginia Health Sciences Center

Questions should be addressed to:

dji@Virginia.EDU