中文摘要：

目的：研究分子遗传学标记JAK2V617F突变在141例慢性骨髓增殖性疾病（cMPD）患者中发生率、突变类型及其与血液学特征的相关性。方法：应用等位基因特异性PCR（AS-PCR）技术进行JAK2V617F点突变的检测，采用PCR-限制性片断长度多态性（RFLP）方法检测JAK2V617F（＋）者的突变类型，然后DNA测序验证。结合临床资料进一步分析。结果：经AS-PCR发现141例cMPD中有73例为JAK2V617F突变阳性样本，其中21例BCR-ABL阳性的CML中未发现突变样本。JAK2V617F（＋）的病例中19例为纯和型突变，54例为杂和型突变。经酶切及测序验证结果相符。结合临床资料进行分析，JAK2V617F突变阳性患者外周血细胞分析中白细胞数和血红蛋白的量较野生型高，而血小板计数较野生型差异无统计学意义。JAK2V617F纯和型突变患者外周血细胞计数中血红蛋白的量较杂合型高，而血小板计数较杂合型低，白细胞计数差异无统计学意义。结论：JAK2V617F点突变可以作为BCR—ABL阴性的MPD诊断的一个参考依据。在突变类型中纯和型突变较为少见。突变类型对血液学特征有一定的影响。

英文摘要：

Objective：To investigate JAK2V617F gene point mutation and evaluate its clinical significance in patients with chronic Myeloproliferative Disease（cMPD）. Method： Genomic DNA from bone marrow or peripheral blood mononuclear cells were extracted from 141 patients with cMPD. AS-PCR （alleles specific polymerase chain reaction） was used to amplify the exon 12 of JAK2 gene which habours V617F mutation. JAK2V617F mutations and the mutation status were analyzed by PCR-RFLP. The results were identified by DNA sequencing. In the present study, we aimed to asses the JAK2 mutational load and its impact on phenotype through the clinical data. Result：In the first part of the study, we evaluated 141 patients with MPD：61 patients with PV, 42 with ET, 12 with IMF, 15 with HES, and 21 with CML. We identified positive JAK2V617F point mutation： 41 in patients with PV （41/61）, 24 in patients with ET （24/42） and 6 in patients with IMF （6/12）, 2 in patients with HES （2/ 5）, respectively. In the second part of study, we found homozygous JAK2V617F mutation.. 18 in patients with PV （18/41）, 3 in ET （3/24）. Patients with JAK2V617F point mutation had higher counts of white blood cell and hemoglobin in peripheral blood than those patients without JAK2V617F point mutation, but there was no significant difference in platelet count. Patients with homozygous JAK2V617F mutation had higher counts of hemoglobin and lower counts of platelets compared with heterozygous patients. There was no significant difference in white blood cell between them. Conclusion：JAK2V617F could be a new diagnostic criteria in MPD which negative BCRABL gene. Most of JAK2 V617F mutations were in heterozygous status. The mutation status can affect the hematologic features.