KMT2A amplification in leukemia detected by cytogenetics

2023-06-05   Roberta Maria da Silva Oliveira Safranauskas, BSc , Maria Gabriella Cordeiro, BSc , Gilmara Sousa e Silva  , Elvira D R P Velloso  

1.Hospital Israelita Albert Einstein

Abstract

A 70 years old with newly de novo acute myelomonocytic leukemia (AML). G-band karyotyping shows the presence of deletion 5q and a ring (r) of chromosome 11 with a homogeneously staining region (hsr) (Figure 1) in all metaphases. Fluorescence in situ hybridization (Figure 2) using KMT2A probe Dual Color, break apart (Metasystems, Germany) shows KMT2A amplification. Metaphase FISH confirmed the KMT2A amplification in the ring chromosome (Figure 3).\nIntrachromosomal regions are hallmarks of genetic amplification in cancer. Ring chromosomes are also vehicles of genes amplification. Although they are often found in solid neoplasm, they are rare in leukemia, been detected in less than 1% of AML with abnormal karyotype and mostly associated with AML with myelodysplastic-related changes and therapy-related AML, older age, complex karyotype and poor prognosis. They could also be detected in myelodysplastic syndromes, chronic myelomonocytic leukemia and chronic myeloid leukemia in blast-phase at diagnosis or during the course of the disease.

Keywords
Amplification,cytogenetics,haematologic,FISH,Ring,KMT2A,11q23,homogeneously staining regions

Clinics and Pathology

Disease

AML

Brief description

Acute myelomonocytic leucemia

Etiology

De novo

Cytology

Bone marrow aspirate shows 63.2% of blast cells (myeloblast and monoblasts)

Phenotype

Abnormal cells (82.5%) phenotype: CD11c+/CD13++/, CD15+/CD33++/CD34++/ CD38+/ CD64+, CD71++/ CD117++/CD123+/CD135+/HLA-DR+/ cyMPO+



Treatment

Still not started.

Prognosis

According to the European Leukemia Net 2022 classification, this is an adverse AML.

Cytogenetics

Cytogenetics morphological

G-band karyotyping shows the presence of deletion 5q and a ring (r) of chromosome 11 with a homogeneously staining region (hsr) (Figure 1) in all metaphases.

Figure 1: 


Cytogenetics molecular

Fluorescence in situ hybridization (figure 2) using KMT2A probe Dual Color, Break apart shows KMT2A amplification. In metaphasic (figure 3) FISH confirmed a amplification in ring.

Figure 2: 


Figure 3:


Result of the Chromosomal Anomaly

Hybrid gene

KMT2A amplification

Bibliography

No bibliography items were found for this article.

Citation

Roberta Maria da Silva Oliveira Safranauskas, BSc ; Maria Gabriella Cordeiro, BSc ; Gilmara Sousa e Silva ; Elvira D R P Velloso

KMT2A amplification in leukemia detected by cytogenetics

Atlas Genet Cytogenet Oncol Haematol. 2023-06-05

Online version: http://atlasgeneticsoncology.org/haematological/209166/files/1685970955_FH23%20366.0010.jpg