A New Complex Karyotype Involving a KMT2A-r Variant Three-Way Translocation in a Rare Clinical Presentation of a Pediatric Patient with Acute Myeloid Leukemia

We describe the clinical and molecular features of a child who presented with a large abdominal mass, AML, and a new CK, involving chromosomes 11, 16, and 19 leading to aKMT2A-MLLT1 fusion and 2 extra copies of theELL gene, thus resulting in the concurrent overexpression ofMLLT1andELL. Molecular cytogenetic studies defined the karyotype as 47,XY,der(11)t(11;16)(q23.3;p11.2),der(16)t(16;19)(p11.2;p13.3),der(19)t(11;19)(q23.3;p13.3),+der(19)t(16;19)(16pter#x2192;p11.2::19p13.3#x2192;19q11::19p11#x2192;19p13.3::16p11.2#x2192;16pter). Array CGH revealed a gain of 30.5 Mb in the 16p13.3p11.2 region and a gain of 18.1 Mb in the 19p13.3p12 region. LDI-PCR demonstrated theKMT2A-MLLT1 fusion. Reverse sequence analysis showed that theMLLT1 gene was fused to the 16p11.2 region. RT-qPCR quantification revealed thatELL andMLLT1 were overexpressed (4- and 10-fold, respectively). In summary, this is a pediatric case of AML presenting a novel complex t(11;16;19) variant with overexpression ofELL andMLLT1.Cytogenet Genome Res
Source: Cytogenetic and Genome Research - Category: Genetics & Stem Cells Source Type: research