Frequency of JAK2 V617F mutation in patients with Philadelphia positive Chronic Myeloid Leukemia in Pakistan

A 68-Year-Old Man with a Cytogenetic Diagnosis of Chronic Myeloid Leukemia and Bone Marrow Findings of Philadelphia Chromosome Translocation Between the Long Arm of Chromosomes 9 and 22, Leading to the BCR-ABL1 Fusion Gene and V617F Mutation in the JAK2 Gene

BACKGROUND Breakpoint cluster region (BCR)-Abelson murine leukemia (ABL1) and Janus Kinase-2 (JAK2) mutations have been thought to be mutually exclusive in myeloproliferative neoplasms (MNPs), but recent data suggest that they can occur together. CASE REPORT A 68-year-old man was referred to the hematology clinic because of an elevated white blood cell count. His medical history included type II diabetes mellitus, hypertension, and retinal hemorrhage. Fluorescence in situ hybridization analysis of the bone marrow was positive for BCR-ABL1 in 66/100 cells. Conventional cytogenetics was positive for the Philadelphia chromosome in 16/20 counted cells. The percentage of BCR-ABL1 was 12%. Considering the patient's age and medical comorbidities, he was started on imatinib 400 mg once daily. Further tests showed JAK2 V617F mutation positivity and absence of acquired von Willebrand disease. He was then started on aspirin 81 mg and hydroxyurea 500 mg once daily, which was later increased to 1000 mg daily. The patient achieved a major molecular response after 6 months of treatment, with undetectable BCR-ABL1 levels. CONCLUSIONS BCR-ABL1 and JAK2 mutations can co-existence in MNPs. Physicians must suspect the presence of one of the MPNs in chronic myeloid leukemia (CML) patients with persistent or increased thrombocytosis, an atypical course of the disease, or hematological abnormalities despite evidence of response or remission of CML. Therefore, testing for JAK2 should be performed accordingly. Combining cytoreductive therapy with tyrosine kinase inhibitors (TKIs) is a therapeutic option when both mutations are present, and TKI alone is not sufficient to control peripheral blood cell counts.

TET2, DNMT3A, IDH1, and JAK2 Mutation in Myeloproliferative Neoplasms in southern Iran

BACKGROUND

Five epigenetic regulator mutations are considered in myeloproliferative neoplasms (MPN) that have prognostic and therapeutic values.

OBJECTIVE

We aimed to evaluate these mutations in MPNs among the Iranian population.

METHODS

We selected 5 mutations in 4 epigenetic regulatory genes [TET2, DNMT3A, IDH1 (rs147001633&rs121913499), and JAK2)] and evaluated 130 patients with MPNs including 78 Philadelphia chromosome negative (49 ETs, 20 PVs, and 9 PMFs) and 52 Philadelphia chromosome-positive patients as well as 51 healthy controls.

RESULTS

Eight patients (6.5%) carried the DNMT3A mutation, 35 (27%) were positive for TET2 mutation and 64 (49.3%) had the JAK2V617F mutation. In the healthy controls, 16 (31.4%) cases had the TET2 mutation (15 Heterozygote + 1 Homozygote) and one had heterozygote JAK2 mutation. There was no statistically significant difference between patient groups for any of these mutations, except for JAK2. The JAK2 mutation rate was 18 (90%), 25 (51%), 7 (77.8%), 14 (26.9%) in polycythemia vera, essential thrombocythemia, primary myelofibrosis, and chronic myelocytic leukemia, respectively. Patients aged 60 and older were more likely to carry the TET2 mutation (23% vs. 39% in younger and older than 60 years old individuals, p=0.025). IDH1 was not detected at all and PV had the highest TET2 mutation 7(35%). Two PMF patients had a history of bone marrow transplantation that were negative for IDH1and DNMT3A and one was positive for TET2 mutation.

CONCLUSION

In the normal Iranian population, the heterozygote form of TET2 mutation is significant, especially in the elderly. No association was found between JAK2 and TET2 mutations. Both of them are more prevalent in the age group of 60 years and older. DNMT3A mutation has a low prevalence and occurs in both positive and negative MPNs.

Concurrent JAK2-Positive Myeloproliferative Disorder and Chronic Myelogenous Leukemia: A Novel Entity? A Case Report With Review of the Literature

JAK2 V617F mutation and BCR-ABL translocation have been considered to be mutually exclusive. However, many cases where both hits coexisted have been reported. We have personally managed a case too. We believe this hybrid entity is underdiagnosed. Thus, we decided to shed light on this "double hit" disease to improve its diagnosis and optimize its treatment. We reviewed the English literature in PubMed since JAK2 discovery. We found 33 cases reported so far. We summarized patient characteristics and analyzed possible interactions between JAK2 and BCR-ABL clones.

Emergence of BCR-ABL1 Chronic Myeloid Leukemia in a JAK2-V617F Polycythemia Vera

Emergence of a new chronic myeloid neoplasm in the setting of a previous one, or their concomitant appearance seems to be a rare event, but plenty of cases have been reported. We describe the case of a patient with JAK2-V617F polycythemia vera, which looses JAK2 clone and develops overt BCR-ABL1 chronic myeloid leukemia after 6 years. Once treatment with tyrosine kinase inhibitors controls BCR-ABL1 clone, JAK2 clone arises again. In this report, we review the literature and discuss the clonal relationship of this event in light of the new molecular data.

Molecular analysis of V617F mutation in Janus kinase 2 gene of breast cancer patients

BACKGROUND

Breast cancer is a multifactorial disease with the highest frequency in females. Genetic and environmental factors can cause mutation in several genes like tyrosine kinase, JAK2 gene which may initiate cancer. Molecular analysis of mutations in the JAK2 gene along with determination of environmental, clinical and haematological risk factors associated with breast cancer patients is need of hour to improve patient's healthcare. Somatic JAK2 valine-to-phenylalanine (617 codon) mutation is one of the widely prevalent mutations.

METHODS

Blood was collected from seventy breast cancer patients after their consent. The questionnaire included risk factors, age group, locality, number of children, tumor type, family history, time of initial diagnosis, no of cycles/month, water conditions and exposure to radiations. Molecular analysis were carried out from genomic DNA using Sanger sequencing and allele-specific PCR to check the V617F point mutation.

RESULTS

The breast cancer risk factors includes unfiltered water (68.57%), urban (58.57%), menopause (55.71%), family history of cancer (18.57%), tumor grades (II, 37.14% and III, 35.71%), consanguineous marriages (44.28%) and having more than 3-4 children (45.71%). Prevalence of breast cancer was higher after the age of 35 and maximum at 35-50. In allele-specific PCR of 70 patients, 25 patients were wild type (229 bp), 25 patients were with partially deleted gene (200 bp), and 20 patient had shown no or less than 40 bp size fragments. In Sanger's sequencing of 70 BC cases, 18% were found to be positive for V617F point mutation, including 6 homozygous (T/T) and 7 heterozygous (G/T) mutations at nucleotide position 1849 in exon 14 of the JAK2 gene.

CONCLUSIONS

Environmental and clinical risk factors were associated with breast cancer which can be overcome by improving awareness of associated risks, health facilities and reducing stress.