Objective: To investigate the frequency and mutational status of JAK2V617F mutation in Chinese patients with chronic myeloproliferative disorders (CMPD) and to study the relative quantification of mutated JAK2 mRNA and the clinical significance.
Methods: JAK2V617F mutation and the mutational status were screened with amplification-refractory mutation system polymerase chain reaction (ARMS-PCR), the relative quantification of mutated JAK2 mRNA was studied by using capillary electrophoresis.
Results: A higher prevalence of JAK2V617F in either the heterozygote or homozygote status in essential thrombocythemia (ET) was observed in elderly patients with ET (P < 0.05). The presence of JAK2V617F was found to be significantly correlated with the age at diagnosis (P < 0.05); patients with age > or = 60 years showed significantly higher JAK2 mutated RNA levels than those with age < 60 years (P < 0.05); the presence of JAK2V617F in polycythemia vera (PV) and ET was found to be significantly associated with higher hemoglobin level and higher leukocyte count (P < 0.05). In addition, higher leukocyte count was observed in homozygous ET patients than in heterozygous ET patients (P < 0.05). The frequency of JAK2V617F mutation and the prevalence of homozygote in PV patients were higher than those in ET patients (P < 0.05). The differences of JAK2V617F mRNA levels among PV, ET and chronic idiopathic myelofibrosis (IMF) were not significant.
Conclusions: ARMS-PCR technique can be used to detect the frequency and mutational status of JAK2V617F mutation owing to its sensitivity and along with capillary electrophoresis, quantitative assay for mutated JAK2 mRNA, diagnosis of CMPD and judgement of prognosis become possible.