Publications by authors named "Myoung Ja Park"

Transient abnormal myelopoiesis (TAM) is a unique clonal myeloproliferation characterized by immature megakaryoblasts that occurs in 5-10% of neonates with Down syndrome (DS). Although TAM regresses spontaneously in most patients, approximately 20% of TAM cases result in early death, and approximately 20% of survivors develop acute megakaryoblastic leukemia (AMKL). We retrospectively reviewed records of 35 DS patients with TAM to determine the correlation between clinical characteristics and blast percentage.

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  • Human herpesvirus-6 (HHV-6) is a common virus usually contracted in infancy, associated with a childhood illness called exanthema subitum, and can exist in a chromosomally integrated form known as iciHHV-6 in some individuals.
  • In patients with primary immunodeficiency disease (PID), like XIAP deficiency, which causes severe complications including recurrent hemophagocytic lymphohistiocytosis (HLH), there is potential for HHV-6 to reactivate, though typically it is considered nonpathogenic.
  • A specific case of a patient with XIAP deficiency undergoing allogeneic bone marrow transplantation (BMT) showed no reactivation of iciHHV-6 despite recurrent
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  • * In a study involving 16 cases of ALL and 1 lymphoma, a total of 2.4% exhibited fusion genes, with typical characteristics including a specific immunophenotype and altered gene expression patterns.
  • * Patients with these fusion genes tended to be older, showed poor treatment outcomes with a high relapse rate, and stem cell transplants did not effectively improve results, highlighting the need for better understanding and treatment strategies for this unique subgroup.
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High PRDM16 (also known as MEL1) expression is a representative marker of acute myeloid leukemia (AML) with NUP98-NSD1 and is a significant predictive marker for poor prognosis in pediatric AML. However, the clinical features of adult AML with PRDM16 expression remain unclear. PRDM16 is highly homologous to MDS1/EVI1, which is an alternatively spliced transcript of MECOM (also known as EVI1).

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ASXL2 is an epigenetic regulator involved in polycomb repressive complex regulation or recruitment. Clinical features of pediatric acute myeloid leukemia (AML) patients with ASXL2 mutations remain unclear. Thus, we investigated frequencies of ASXL1 and ASXL2 mutations, clinical features of patients with these mutations, correlations of these mutations with other genetic alterations including BCOR/BCORL1 and cohesin complex component genes, and prognostic impact of these mutations in 369 pediatric patients with de novo AML (0-17 years).

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Pediatric acute megakaryoblastic leukemia in non-Down syndrome (AMKL) is a unique subtype of acute myeloid leukemia (AML). Novel CBFA2T3-GLIS2 and NUP98-KDM5A fusions recurrently found in AMKL were recently reported as poor prognostic factors. However, their detailed clinical and molecular characteristics in patients treated with recent improved therapies remain uncertain.

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Acute myeloid leukaemia (AML) is a molecularly and clinically heterogeneous disease. Targeted sequencing efforts have identified several mutations with diagnostic and prognostic values in KIT, NPM1, CEBPA and FLT3 in both adult and paediatric AML. In addition, massively parallel sequencing enabled the discovery of recurrent mutations (i.

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Recent reports described the NUP98-NSD1 fusion as an adverse prognostic marker for acute myeloid leukaemia (AML) and PRDM16 (also known as MEL1) as the representative overexpressed gene in patients harbouring NUP98-NSD1 fusion. PRDM16 gene expression levels were measured via real-time polymerase chain reaction in 369 paediatric patients with de novo AML, of whom 84 (23%) exhibited PRDM16 overexpression (PRDM16/ABL1 ratio ≥0·010). The frequencies of patients with high or low PRDM16 expression differed widely with respect to each genetic alteration, as follows: t(8;21), 4% vs.

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Mutations in the colony-stimulating factor 3 receptor (CSF3R) and calreticulin (CALR) genes have been reported in a proportion of adults with myeloproliferative disease. However, little is known about CSF3R or CALR mutations in paediatric myeloid disorders. We analysed CSF3R exons 14 and 17, and CALR exon 9, using direct sequencing in samples of paediatric acute myeloid leukaemia (AML; n = 521), juvenile myelomonocytic leukaemia (JMML; n = 40), myelodysplastic syndrome (MDS; n = 20) and essential thrombocythaemia (ET; n = 21).

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Pleuropulmonary blastoma (PPB) is a rare pediatric malignancy whose pathogens are poorly understood. Recent reports suggest that germline mutations in the microRNA-processing enzyme DICER1 may contribute to PPB development. To investigate the genetic basis of this cancer, we performed whole-exome sequencing or targeted deep sequencing of multiple cases of PPB.

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  • * A study of 25 DS-TAM patients found that 16% (4 patients) died before 6 months, with two of those deaths linked to liver failure.
  • * Elevated D-bilirubin (D-Bil) levels were common in all DS patients, suggesting a potential risk for liver disease regardless of symptoms; ongoing monitoring of D-Bil levels is recommended for early detection of liver problems.
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  • Transient abnormal myelopoiesis (TAM) primarily affects infants with Down syndrome and can sometimes progress to a more serious condition known as Down syndrome-related acute megakaryoblastic leukemia (DS-AMKL).
  • TAM is usually self-limiting and is associated with GATA1 mutations and trisomy 21, the extra chromosome present in Down syndrome.
  • Genomic analysis shows that DS-AMKL develops from TAM due to further mutations in various genes and pathways, indicating a complex evolution from a pre-existing condition.
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Mutations in Wilms tumor 1 (WT1) have been reported in 10-22 % of patients with cytogenetically normal acute myeloid leukemia (CN-AML), but the prognostic implications of these abnormalities have not been clarified in either adults or children. One hundred and fifty-seven pediatric AML patients were analyzed for WT1 mutations around hotspots at exons 7 and 9; however, amplification of the WT1 gene by the reverse transcriptase-polymerase chain reaction was not completed in four cases (2.5 %).

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Background: Mutations in the ATP6V1B1 and the ATP6V0A4 genes cause primary autosomal-recessive distal renal tubular acidosis (dRTA). Large deletions of either gene in patients with dRTA have not been described.

Methods: The ATP6V1B1 and ATP6V0A4 genes were directly sequenced in 11 Japanese patients with primary dRTA from nine unrelated kindreds.

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The cryptic t(5;11)(q35;p15.5) creates a fusion gene between the NUP98 and NSD1 genes. To ascertain the significance of this gene fusion, we explored its frequency, clinical impact, and gene expression pattern using DNA microarray in pediatric acute myeloid leukemia (AML) patients.

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  • - Kasabach-Merritt phenomenon (KMP) is a rare condition with unclear optimal treatments, particularly for those unresponsive to standard therapies; 11 cases from a 13-year review were analyzed.
  • - Most patients received steroids as their initial treatment, but eight needed additional therapies, including interferon, radiotherapy, and chemotherapy, with chemotherapy showing notable effectiveness.
  • - The findings suggest that chemotherapy is particularly beneficial for cases of KMP that do not respond to steroids, especially in patients older than one year who remained dependent on therapy.
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Recently, bone marrow transplantation from an unrelated donor has been recommended as an option for the treatment of very severe aplastic anemia (vSAA) refractory to immunosuppressive therapy (IST) in the absence of a human leukocyte antigen-matched related donor (MRD). For SAA patients with complications such as bacterial infections, prompt transplantation using either a mismatched related donor or cord blood (CB) becomes necessary. However, the former option is associated with graft-versus-host disease, whereas the latter option is associated with a more significant risk of graft failure.

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Chronic mucocutaneous candidiasis (CMC) is a heterogeneous group of primary immunodeficiency diseases characterized by chronic and recurrent Candida infections of the skin, nails, and oropharynx. Gain-of-function mutations in STAT1 were very recently shown to be responsible for autosomal-dominant or sporadic cases of CMC. The reported mutations have been exclusively localized in the coiled-coil domain, resulting in impaired dephosphorylation of STAT1.

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Mutations in RAS are frequent in acute myeloid leukemia (AML), and are thought to contribute to leukemogenesis in a subset of patients; however, their prognostic significance has not been firmly established. One hundred and fifty-seven pediatric patients with AML were analyzed for NRAS and KRAS mutations around hot spots at codons 12, 13, and 61. Twenty-nine patients (18.

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Trib1 has been identified as a myeloid oncogene in a murine leukemia model. Here we identified a TRIB1 somatic mutation in a human case of Down syndrome-related acute megakaryocytic leukemia. The mutation was observed at well-conserved arginine 107 residue in the pseudokinase domain.

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Familial platelet disorder with a propensity to develop acute myeloid leukemia (FPD/AML) is a rare autosomal dominant disease characterized by thrombocytopenia, abnormal platelet function, and a propensity to develop myelodysplastic syndrome (MDS) and AML. So far, > 20 affected families have been reported. Recently, a second RUNX1 alteration has been reported; however, no additional molecular abnormalities have been found so far.

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