O'Connor H E, Butler T A, Clark R, Swanton S, Harrison C J, Secker-Walker L M, Foroni L
Department of Hematology and Cytogenetics, The Royal Free Hospital and School of Medicine, London, UK.
Leukemia. 1998 Jul;12(7):1099-106. doi: 10.1038/sj.leu.2401070.
Involvement of the ETV6 gene, located at 12p13, has been investigated in 20 patients with an abnormality of the short arm of chromosome 12 (abn 12p) detected cytogenetically. Patients in the study had c/pre-B acute lymphoblastic leukemia (ALL) (nine children and three adults), T-ALL (three adults), acute myeloid leukemia (AML) (two adults), biphenotypic acute leukemia (Bip-L) (one adult), myelodysplasia (MDS) (one adult) and chronic myelomonocytic leukemia (CMML) (one child). Abnormalities of 12p comprised deleted (del)(12p) alone (seven cases), add(12p) alone (seven cases), del(12p) and add(12p) (one case) and balanced translocations of 12p to 1p13, 1q31, 10q11, 14q11 and 15q15 (one case of each). A novel, exon-specific RT-PCR assay identified breakpoints in ETV6 in nine of 19 cases, and showed breakpoints in intron 5 (seven cases of children with c-ALL), in intron 4 (in one adult with Bip-L) and in intron 2 (in one adult with AML). RT-PCR for the ETV6/AMLI fusion (tested in 19 cases) was positive using standard primers in five cases (four of which had shown rearrangements in intron 5) and occurred as a variant fusion in a sixth case (also positive for a rearrangement in intron 5) using 3' RACE PCR. Southern blotting confirmed rearrangements in intron 5 in the five cases available for analysis and revealed a rearrangement in intron 5 in one of 10 cases with no evidence of intron 5 involvement by RT-PCR. Rearrangements in intron 5 of ETV6 were found in eight of nine cases of children with c-ALL of which six carried the ETV6/AMLI fusion. Heterozygosity within intron 5 (revealed by the genomic probe B1) was found in seven of 11 cases tested. Deletion of one allele was indicated in three cases with del(12p) and one case with add(12p). This study, using a combination of ETV6 exon-specific RT-PCR, RT-PCR for ETV6/AMLI and Southern blotting has shown that rearrangement and/or deletion of ETV6 may occur in up to 70% of patients with abn 12p. Furthermore, 90% of children in this study with an abn 12p and c-ALL, carried a rearrangement of ETV6 in intron 5.
对20例经细胞遗传学检测发现12号染色体短臂异常（abn 12p）的患者，研究了位于12p13的ETV6基因的受累情况。研究中的患者有普通型/前体B淋巴细胞白血病（ALL）（9名儿童和3名成人）、T淋巴细胞白血病（T-ALL）（3名成人）、急性髓系白血病（AML）（2名成人）、双表型急性白血病（Bip-L）（1名成人）、骨髓增生异常综合征（MDS）（1名成人）和慢性粒单核细胞白血病（CMML）（1名儿童）。12p异常包括单独的缺失（del）（12p）（7例）、单独的附加（add）（12p）（7例）、del（12p）和add（12p）（1例）以及12p与1p13、1q31、10q11、14q11和15q15的平衡易位（各1例）。一种新的外显子特异性逆转录聚合酶链反应（RT-PCR）检测方法在19例中的9例中鉴定出ETV6中的断点，并且显示在第5内含子中有断点（7例c-ALL儿童）、在第4内含子中有断点（1例Bip-L成人）以及在第2内含子中有断点（1例AML成人）。使用标准引物对ETV6/AMLI融合进行的RT-PCR（在19例中检测）在5例中呈阳性（其中4例在第5内含子中显示有重排），并且在第6例中作为变异融合出现（第5内含子中的重排也呈阳性），使用3'端快速扩增cDNA末端（3' RACE）PCR。Southern印迹证实了可用于分析的5例中第5内含子的重排，并且在10例中未通过RT-PCR显示第5内含子受累证据的1例中揭示了第5内含子的重排。在9例c-ALL儿童中的8例中发现ETV6第5内含子的重排，其中6例携带ETV6/AMLI融合。在检测的11例中的7例中发现第5内含子内的杂合性（由基因组探针B1揭示）。在3例del（12p）和1例add（12p）中表明一个等位基因缺失。本研究使用ETV6外显子特异性RT-PCR、ETV6/AMLI的RT-PCR和Southern印迹的组合，表明ETV6的重排和/或缺失可能发生在高达70%的abn 12p患者中。此外，本研究中90%的具有abn 12p和c-ALL的儿童在第5内含子中有ETV6的重排。
