Matveeva Elena, Kazakova Anna, Olshanskaya Yulia, Tsaur Grigory, Shelikhova Larisa, Meyer Claus, Marschalek Rolf, Novichkova Galina, Maschan Michael, Maschan Aleksey
Federal Scientifc Clinical Centre of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.
Federal Scientifc Clinical Centre of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.
Cancer Genet. 2015 Apr;208(4):148-51. doi: 10.1016/j.cancergen.2015.03.001. Epub 2015 Mar 7.
The KMT2A gene (previously known as MLL) located at 11q23 is often involved in recurrent chromosomal translocations that lead to the development of acute leukemia, particularly in infants. Acute leukemias with KMT2A rearrangements have different prognoses, which depend on the partner gene involved in the translocation. The detection of all possible types of KMT2A gene rearrangements is of key importance for the identification of biological subgroups, which may differ in clinical outcome. In this report, we describe a case study of a 7-month-old boy who presented with AML-M4; however, no obvious 11q23 rearrangement was detected in the analyzed karyotype. Fluorescence in situ hybridization evaluation showed a nonstandard signal distribution in blast cells, corresponding to the presence of two KMT2A copies and one additional copy of 5'-KMT2A inserted into the long arm of the X chromosome (ins(X;11)(q28;q23q23)). Subsequent molecular analysis showed a novel variant form of the previously described KMT2A-FLNA fusion gene, in which the KMT2A intron 9 is fused to the FLNA exon 16.
位于11q23的KMT2A基因（以前称为MLL）经常参与导致急性白血病发生的复发性染色体易位，尤其是在婴儿中。伴有KMT2A重排的急性白血病具有不同的预后，这取决于易位中涉及的伙伴基因。检测所有可能类型的KMT2A基因重排对于识别生物学亚组至关重要，这些亚组在临床结果上可能有所不同。在本报告中，我们描述了一名7个月大男孩的病例研究，该男孩表现为AML-M4；然而，在分析的核型中未检测到明显的11q23重排。荧光原位杂交评估显示原始细胞中存在非标准信号分布，对应于两个KMT2A拷贝以及一个额外的5'-KMT2A拷贝插入到X染色体长臂（ins(X;11)(q28;q23q23)）。随后的分子分析显示了先前描述的KMT2A-FLNA融合基因的一种新型变异形式，其中KMT2A内含子9与FLNA外显子16融合。
