Thrombotic thrombocytopenic purpura as a rare cause of anemia with thrombocytopenia in childhood: report of 2 cases

Thrombotic thrombocytopenic purpura (TTP) is a rare multisystem disorder characterized by single or recurrent episodes of thrombocytopenia, microangiopathic hemolytic anemia and widespread microvascular thrombosis, which causes significant morbidity and mortality unless promptly recognized and treated. The underlying pathogenesis is a defect in von Willebrand factor (vWF) cleaving protease, called "A Disintegrin and Metalloproteinase with Thrombospondin Type 1 Repeats 13 (ADAMTS-13)". There are 2 forms: congenital TTP (ADAMTS-13 gene mutations) and acquired TTP (autoantibodies and ADAMTS-13 deficiency). We presented two patients who initially presented with thrombotic microangiopathy and were later diagnosed with TTP upon demonstration of the deficiency in ADAMTS-13 activity

Amyloidosis in a Patient With Congenital Neutropenia Because of G6PC3 Deficiency

Glucose-6-phosphatase catalytic subunit 3 (G6PC3) deficiency is a recently identified form of congenital neutropenia associated with developmental anomalies. The severity of neutropenia and the clinical spectrum are highly variable. Aside from infectious complications and extrahematologic features, inflammatory bowel disease and autoinflammatory complications are less frequently observed manifestations. However, amyloidosis has never been reported in G6PC3 deficiency. Here, we present a 12-year-old patient with incidentally discovered neutropenia because of the p.E65A (c.194A>C) variant of the G6PC3 gene. He had recurrent aphthae and abdominal pain episodes, and developed nephrotic-range proteinuria, amyloidosis, and end-stage renal failure during follow-up

Prognostic gene alterations and clonal changes in childhood B-ALL

Genomic profiles of leukemia patients lead to characterization of variations that provide the molecular classification of risk groups, prediction of clinical outcome and therapeutic decisions. In this study, we examined the diagnostic (n = 77) and relapsed (n = 31) pediatric B-cell acute lymphoblastic leukemia (B-ALL) samples for the most common leukemia-associated gene variations CRLF2, JAK2, PAX5 and IL7R using deep sequencing and copy number alterations (CNAs) (CDKN2A/2B, PAX5, RB1, BTG1, ETV6, CSF2RA, IL3RA and CRLF2) by multiplex ligation proximity assay (MLPA), and evaluated for the clonal changes through relapse. Single nucleotide variations SNVs were detected in 19% of diagnostic 15.3% of relapse samples. The CNAs were detected in 55% of diagnosed patients; most common affected genes were CDKN2A/2B, PAX5, and CRLF2. Relapse samples did not accumulate a greater number of CNAs or SNVs than the cohort of diagnostic samples, but the clonal dynamics showed the accumulation/disappearance of specific gene variations explained the course of relapse. The CDKN2A/2B were most frequently altered in relapse samples and 32% of relapse samples carried at least one CNA. Moreover, CDKN2A/2B alterations and/or JAK2 variations were associated with decreased relapse-free survival. On the other hand, CRLF2 copy number alterations predicted a better survival rate in B-ALL

HighTUBB2Aexpression in childhood T-ALL is correlated with the clinical outcome

Introduction Microtubules are polymers that perform functions such as mitosis, intracellular transport, cell morphology, and ciliary and flagellar motility. Since microtubules are taking active part in cell division, they are among direct targets of several antimitotic drugs. Methods Expression levels of tubulin isotypes were analyzed in microarray data of childhood diagnostic T-ALL samples (n = 31) and healthy thymocytes (n = 7). Findings were validated with qPCR in separate T-ALL cohort (n = 48), and clinical correlation analyses were performed.TUBB2A's effects were tested with siRNA-mediated knockdown in MOLT4 cell line, and apoptosis assay was carried out at 24, 48, and 72 hours time points. Results In microarray data,TUBB2Awas found to be the only differentially expressed tubulin isotype (adj.Pvalue = .01), which was validated by qPCR (P = .02). Samples representing differentiation stages of T cell showed an increasing trend ofTUBB2Atoward mature T-cell stage.TUBB2Aexpression was significantly higher in high-risk group patients (P = .026) and in a group with WBC counts >100 (x10(9)cells/L) (P = .029). HighTUBB2Awas also found to be a predictor of shorter OS (P = .029) and RFS (P = .042). Conclusion Aberrant expression of TUBB isotypes can affect the balance of microtubules or microtubule-associated proteins, which might lead to drug resistance/relapse. Contribution of cytoskeleton proteins to drug resistance needs further investigation, and understanding aberrant expression and mode of action of microtubules will improve therapy strategies

Prognostic evidence of LEF1 isoforms in childhood acute lymphoblastic leukemia

Introduction The lymphoid enhancer factor 1 (LEF1) is a DNA-binding transcription factor that functions in the Wnt signaling pathway. Increased LEF1 activity is associated with progression of several types of cancer including leukemia. Here, we investigated LEF1 isoform expression and genomic variations in acute lymphoblastic leukemia (ALL)