Nandagopalan S Rajashree, Kuila Nivedita, Biswas Sutapa, Pattnayak Naresh Chandra, Biswas Gyanashyam, Chakraborty Soumen
Institute of Life Sciences, Bhubaneswar, Odisha, India.
Sparsh Hospital & Critical Care, Bhubaneswar, Odisha, India.
Indian J Med Res. 2016 May;143(Supplement):S136-S141. doi: 10.4103/0971-5916.191816.
BACKGROUND & OBJECTIVES: Chronic myeloid leukaemia is (CML) characterized by the presence of a hallmark chromosomal translocation, the Philadelphia chromosome. Although there are many reports available regarding the different variants of BCR-ABL in CML, we studied the co-expression of e13a2 and e14a2 transcripts and a few polymorphisms in CML patients.
Molecular genetics approach was adapted to screen for polymorphisms, mutation and translocation in BCR, ABL kinase domain and BCR-ABL breakpoint region in 73 CML patients.
All eight patients with dual transcripts were found to harbour an exonic polymorphism (c.2700 T>C) and an intronic polymorphism (g.109366A>G) that were earlier reported to be associated with co-expression of both the transcripts. We also observed c.763G>A mutation in ABL kinase domain and two polymorphisms, c.2387 A>G and c.2736A>G in the BCR gene.
INTERPRETATION & CONCLUSIONS: Though our data support the previous findings that co-expression of BCR-ABL transcripts is due to the occurrence of exonic and intronic polymorphisms in the BCR gene, it also shows that the intronic polymorphism can arise without the linked exonic polymorphism. The occurrence of ABL kinase domain mutation is less frequent in Indian population.
慢性髓性白血病（CML）的特征是存在标志性染色体易位——费城染色体。尽管有许多关于CML中BCR-ABL不同变体的报道，但我们研究了CML患者中e13a2和e14a2转录本的共表达以及一些多态性。
采用分子遗传学方法筛查73例CML患者的BCR、ABL激酶结构域和BCR-ABL断裂点区域的多态性、突变和易位。
所有8例具有双转录本的患者均存在一个外显子多态性（c.2700 T>C）和一个内含子多态性（g.109366A>G），此前报道这两个多态性与两种转录本的共表达有关。我们还在ABL激酶结构域中观察到c.763G>A突变，以及BCR基因中的两个多态性，即c.2387 A>G和c.2736A>G。
尽管我们的数据支持先前的发现，即BCR-ABL转录本的共表达是由于BCR基因中外显子和内含子多态性的出现，但也表明内含子多态性可以在没有相关外显子多态性的情况下出现。ABL激酶结构域突变在印度人群中的发生率较低。
