Myeloid Leukemia

Diagnosis of CBFB-MYH11-Positive AML 163
10
Diagnosis and Monitoring of CBFB-MYH11-Positive
Acute Myeloid Leukemia by Qualitative
and Quantitative RT-PCR
Bert A. van der Reijden and Joop H. Jansen
Summary
During the last decade, many mutations present in myeloid leukemias have been molecularly
characterized. Several of these mutations have clear prognostic impact. The molecular
screening of these mutations has now become an essential part in several risk-adapted international
clinical trials. Here we describe protocols for the qualitative and quantitative detection of
leukemic cells that are characterized by a CBFB-MYH11 gene fusion.
Key Words: CBFB-MYH11; inv(16); t(16;16); M4Eo; qualitative RT-PCR; quantitative
RT-PCR; minimal residual disease; control gene.
1. Introduction
The CBFB-MYH11 gene fusion is frequently found in adult patients with de
novo acute myeloid leukemia. The incidence is approx 10% (1). Approximately
one-half of the CBFB-MYH11-positive patients exhibit FAB morphology
M4Eo, whereas various other FAB morphologies are observed in the remaining
50%. Thus, FAB morphology is not a good predictor for the presence of the
CBFB-MYH11 gene fusion. In most CBFB-MYH11-positive cases, the fusion
can be cytogenetically observed as an inversion on chromosome 16,
inv(16)(p13q22), or, less frequently, as a translocation between the two chromosomes
16—t(16;16)(p13;q22). However, CBFB-MYH11-positive cases are
known that do not show any cytogenetically visible chromosome 16 abnormalities
(2). Because patients with the CBFB-MYH11 fusion have a relatively
favorable prognosis and may require adapted treatment, reliable tools are
required for its detection. At present, qualitative CBFB-MYH11 PCR is one of
the most powerful methods to identify CBFB-MYH11-positive cases. Because
the CBFB-MYH11 gene fusion is tumor cell specific, it is also possible to quan-
From: Methods in Molecular Medicine, Vol. 125: Myeloid Leukemia: Methods and Protocols
Edited by: H. Iland, M. Hertzberg, and P. Marlton © Humana Press Inc., Totowa, NJ
163