Genetic Alterations in Essential Thrombocythemia Progression to Acute Myeloid Leukemia: A Case Series and Review of the Literature.

The genetic events associated with transformation of myeloproliferative neoplasms (MPNs) to secondary acute myeloid leukemia (sAML), particularly in the subgroup of essential thrombocythemia (ET) patients, remain incompletely understood. Deep studies using high-throughput methods might lead to a better understanding of genetic landscape of ET patients who transformed to sAML. We performed array-based comparative genomic hybridization (aCGH) and whole exome sequencing (WES) to analyze paired samples from ET and sAML phases. We investigated five patients with previous history of MPN, which four had initial diagnosis of ET (one case harboring JAK2 p.Val617Phe and the remaining three CALR type II p.Lys385fs*47), and one was diagnosed with MPN/myelodysplastic syndrome with thrombocytosis (SF3B1 p.Lys700Glu). All were homogeneously treated with hydroxyurea, but subsequently transformed to sAML (mean time of 6 years/median of 4 years to transformation). Two of them have chromosomal abnormalities, and both acquire 2p gain and 5q deletion at sAML stage. The molecular mechanisms associated with leukemic progression in MPN patients are not clear. Our WES data showed TP53 alterations recurrently observed as mutations (missense and frameshift) and monoallelic loss. On the other hand, aCGH showed novel chromosome abnormalities (+2p and del5q) potentially associated with disease progression. The results reported here add valuable information to the still fragmented molecular basis of ET to sAML evolution. Further studies are necessary to identify minimal deleted/amplified region and genes relevant to sAML transformation.

Familial Myelodysplastic/Acute Leukemia Syndromes-Myeloid Neoplasms with Germline Predisposition.

Although most cases of myeloid neoplasms are sporadic, a small subset has been associated with germline mutations. The 2016 revision of the World Health Organization classification included these cases in a myeloid neoplasm group with a predisposing germline mutational background. These patients must have a different management and their families should get genetic counseling. Cases identification and outline of the major known syndromes characteristics will be discussed in this text.

An unusual long-term outcome of a child with primary myelofibrosis harboring a JAK2 mutation.

We report an extremely rare case of a female child who presented the onset of primary myelofibrosis (PMF) harboring JAK2 (Janus Kinase 2 gene) mutation (JAK2V617F) when she was 15 months old. She was monitored over 25 years, a period in which she was treated with spleen radiotherapy and recombinant interferon α. She also underwent splenectomy when she was 13 years old, due to massive splenomegaly, anemia and various infection disease episodes. The longstanding evolution of the patient enabled us to verify that there were no complications related to post-splenectomy events and/or blast transformation. To the best of our knowledge, this is the first reported case of severe PMF with JAK2 mutation in a child. We provide evidence that a better quality of life and long survival in pediatric PMF may be provided by splenectomy.

JAK2V617F mutation in patients with splanchnic vein thrombosis.

BACKGROUND: Splanchnic vein thrombosis can be the presenting manifestation of myeloproliferative neoplasms. However, the diagnosis of a myeloproliferative neoplasm in these patients is often problematic, and more objective criteria are needed. AIM: To determine the frequency of the mutation JAK2V617F in patients with splanchnic vein thromboses. METHODS: A consecutive series of 108 adult patients with portal vein thrombosis (n = 77) and Budd-Chiari syndrome (n = 31) referred for hemostasis evaluation was retrospectively studied, with a median follow-up of 51 months (1-104). RESULTS: One or more prothrombotic risk factors were present in 63% of the patients. Twenty-four (22%) out of the 108 patients presented the JAK2V617F, including 2 cirrhotic patients. Most had a low mutated allele burden (median 16.5%). JAK2V617F was present in all four patients with a previous diagnosis of a myeloproliferative neoplasm. In nine JAK2V617F-positive patients, the diagnosis of a myeloproliferative neoplasm was made at the thrombosis work-up, during follow-up or after JAK2V617F detection. Among the other 11 patients carrying the mutation, 2 patients have died, 4 had no evidence suggesting a myeloproliferative neoplasm, 1 had a normal bone marrow biopsy, and the other 4 could not be persuaded to undergo a biopsy. Among the patients without an overt myeloproliferative neoplasm, 15 out of 99 (15%) presented the JAK2V617F mutation. None of the JAK2V617F-negative patients have developed signs of a myeloproliferative neoplasm during follow-up. CONCLUSIONS: Our findings suggest that JAK2V617F occurs in a high proportion of patients with splanchnic vein thrombosis, and reinforces the diagnostic utility of JAK2V617F testing in this setting.

Use of V H, D and J H immunoglobulin gene segments in Brazilian patients with chronic lymphocytic leukaemia (CLL)

Chronic lymphocytic leukaemia (CLL) is a haematological malignancy for which reliable prognostic markers are needed in view of its clinical heterogeneity. In approximately 50 percent of CLL patients, immunoglobulin (Ig) rearrangements are modified by somatic hypermutation (SHM), a process that represents a reliable prognostic indicator of favourable progression. In this study, we investigated SHM in 37 Brazilian CLL patients and identified the preferential involvement of specific immunoglobulin gene families and segments through PCR-amplified fragments or subcloned fragments. Forty-one rearrangements were observed and 37 of them were functional. A 98 percent homology cut-off with germinal sequences showed 18 patients (48.7 percent) with SHM. Unmutated cases showed a poorer clinical outcome. V H3 was the most frequent V H family, followed by V H4. The V H4-39 segment was the most frequently used, mainly in unmutated cases, while the V H3 family was predominant in mutated cases. The D3 and J H4/J H6 families were the most frequently observed.