Search

Background Myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a new disease entity in the current WHO classification. Genetically, 60%–90% of cases have mutations in SF3B1 , strongly associated with RS, and more than half of them cooccur with JAK2 V617F. This report describes the rare case of MDS/MPN-RS-T with SF3B1 mutation cooccurring with an MPL mutation. Methods We report a 79-year-old man who was referred because of generalized edema. Peripheral blood testing showed macrocytic anemia and thrombocytosis, and bone marrow analysis demonstrated dyserythropoiesis with RS and increased megakaryocytes. A molecular study was performed to detect SF3B1 mutations and recurrent mutations in MPN disease (JAK2 V617F/exon 12, CALR gene exon 9, and MPL gene exon 10 mutations). Results The molecular study revealed SF3B1 K666T and MPL W515R mutations, while BCR - ABL1 or JAK2 V617F/exon 12 and CALR mutations were all negative. Conclusion This is a rare case of concomitant SF3B1 and MPL mutations in MDS/MPN-RS-T. [ABSTRACT FROM AUTHOR]

Inhibitor development is the most serious complication in patients with hemophilia. We investigated association of HLA genotypes with inhibitor development in Korean patients with severe hemophilia A (HA). HLA genotyping was done in 100 patients with severe HA including 27 patients with inhibitors. The allele frequencies between inhibitor-positive and inhibitor-negative patients were compared. HLA class I alleles were not associated with the inhibitor status. In HLA class II, DRB1*15 [n = 100, odds ratio (OR) 0.217, P = 0.028] and DPB1*05:01 [OR 0.461, P = 0.026] were negatively associated with inhibitor development. In a subgroup of patients with intron 22 inversion, C*07:02 was positively associated with inhibitor development [n = 30, OR 5.500, P = 0.043]. In the subgroup of patients without intron 22 inversion, the negative association between DPB1*05:01 and inhibitor development was reinforced [n = 70, OR 0.327, P = 0.010], and positive association of DRB1*13:02 and DPB1*04:01 with inhibitor development was identified [OR 3.059, P = 0.037 for both]. Previously reported risk alleles were not consistently associated with inhibitor risk in our series. This study demonstrated the profile of HLA alleles associated with inhibitor risk in Korean patients with severe HA was different from that in patients of other ethnicities, which needs to be considered in risk assessment and management. [ABSTRACT FROM AUTHOR]

The article presents a case study which focused on a 47-year-old female patient with metastatic acral melanoma (AM) of the breast. Topics discussed include the presence of activated KIT gene mutations in AM, results of the physical examination, staging computed tomography, and positron emission tomography scans performed, and the administration of biochemotherapy, whole-brain radiation therapy, and medications such as cisplatin and vinblastine.

Most cases of erythrocytosis occur secondary to chronic tissue hypoxia or as a clonal disease such as polycythemia vera with somatic mutations in the Janus kinase 2 ( JAK2) gene. Rarely, erythrocytosis is caused by hereditary gene mutations. This study investigated hereditary gene mutations in 38 unrelated Korean patients with isolated erythrocytosis without (1) JAK2 mutation and (2) secondary causes of erythrocytosis other than smoking history. Direct sequencing analyses were performed on six genes associated with hereditary erythrocytosis [ HBB, exon 2 and exon 3 of HBA2, VHL, EGLN1 (previously PHD2), exon 12 of EPAS1 (previously HIF2A), and exons 5-8 of EPOR]. As a result, mutations were detected in five patients (three never smokers and two current smokers) out of 38 patients (13.2 %). The mutations detected in those five patients were EPOR:p.W439*, EPOR:p.G212C, HBB:p.H98Q (or conventionally H97Q, Hb Malmö [β 97(FG4) His > Gln]), HBB:p.V138M (V137M), and EGLN1:p.L279Tfs43*, all in heterozygous state. No patient had mutations in HBA2, VHL, or in EPAS1. This study indicates that workup for hereditary gene mutations is needed for isolated erythrocytosis with or without smoking history. [ABSTRACT FROM AUTHOR]

Genetic alterations implicated in the leukemogenesis of T cell acute lymphoblastic leukemia (T-ALL) have been identified in recent years. In this study, we investigated gene mutation profiles and prognostic implications in a series of Korean T-ALL patients. The study patients were 29 Korean patients with T-ALL; 13 adults (45 %) and 16 children (55 %; male-to-female ratio, 25:4). Clinical, hematologic, and cytogenetic findings were reviewed. We performed mutation analyses for NOTCH1, FBXW7, PHF6, and IL7R genes and survival analyses according to the mutational status. Gene mutations were identified in 66 % of the patients in our series (19/29). Eighteen patients (62 %) had NOTCH1/ FBXW7 mutations. Sixteen patients (55 %) had NOTCH1 mutations including nine novel mutations, and eight patients (28 %) had known FBXW7 mutations. Eight patients (28 %; six males and two females) had PHF6 mutations including four novel mutations. Three patients (10 %) had IL7R mutations, which were all novel in-frame insertion or deletion-insertions. The gene mutation profile combined with cytogenetics and FISH study for the p16 gene detected genetic aberrations in 90 % of patients (26/29). There was no significant difference in the frequency of gene mutations between the pediatric and adult patients with T-ALL. Survival analyses suggested a favorable prognostic implication of NOTCH1 mutations in adult T-ALL. Gene mutation studies for NOTCH1, FBXW7, PHF6, and IL7R could detect genetic alterations in a majority of Korean T-ALL patients with novel mutations. We observed similar mutation profiles between adult and pediatric T-ALL, and a favorable prognostic implication of NOTCH1 mutations in adult T-ALL. [ABSTRACT FROM AUTHOR]

Familial hemophagocytic lymphohistiocytosis (familial HLH or FHL) is a potentially fatal autosomal recessive disorder. Our previous study demonstrated that UNC13D mutations (FHL3) account for ∼90 % of FHL in Korea with recurrent splicing mutation c.754-1G>C (IVS9-1G>C). Notably, half of the FHL3 patients had a monoallelic mutation of UNC13D. Deep intronic mutations in UNC13D were recently reported in patients of European descent. In this study, we performed targeted mutation analyses for deep intronic mutations and investigated on the founder effect in FHL3 in Korean patients. The study patients were 72 children with HLH including those with FHL3 previously reported to have a monoallelic UNC13D mutation. All patients were recruited from the Korean Registry of Hemophagocytic Lymphohistiocytosis. In addition to conventional sequencing of FHL2-4, targeted tests for c.118-308C>T and large intronic rearrangement mutations of UNC13D were performed. Haplotype analysis was performed for founder effects using polymorphic markers in the FHL3 locus. FHL mutations were detected in 20 patients (28 %). Seventeen patients had UNC13D mutations (FHL3, 85 %) and three had PRF1 mutations (FHL2, 15 %). UNC13D:c.118-308C>T was detected in ten patients, accounting for 38 % of all mutant alleles of UNC13D, followed by c.754-1G>C (26 %). Haplotype analyses revealed significantly shared haplotypes in both c.118-308C>T and c.754-1G>C, indicating the presence of founder effects. The deep intronic mutation UNC13D:c.118-308C>T accounts for the majority of previously missing mutations and is the most frequent mutation in FHL3 in Korea. Founder effects of two recurrent intronic mutations of UNC13D explain the unusual predominance of FHL3 in Korea. [ABSTRACT FROM AUTHOR]

Core binding factor (CBF)-positive acute myeloid leukemia (AML) presents a favorable prognosis, except for patients with KIT mutation, especially D816 mutation. The current retrospective study attempted to validate a prognostic role of KIT mutation in 121 Korean patients with CBF AML. The study patients consisted of 121 patients with CBF AML (82 patients with RUNX1/ RUNX1T1 [67.8 %] and 39 patients with CBFB/ MYH11 [32.2 %]) recruited from eight institutions in Korea. All patients received idarubicin plus cytarabine or behenoyl cytosine arabinoside 3 + 7 induction chemotherapy. The KIT gene mutation status was determined by direct sequencing analyses. A KIT mutation was detected in 32 cases (26.4 %) in our series of patients. The KIT mutation was most frequent in exon 17 ( n = 18, 14.9 %; n = 16 with D816 mutation), followed by exon 8 ( n = 10, 8.3 %). The presence of KIT D816 mutation was associated with adverse outcomes for the event-free survival ( p = 0.03) and for the overall survival ( p = 0.02). The unfavorable impact of D816 mutation was more prominent when the analysis was confined to the RUNX1/ RUNX1T1 subtype. The KIT mutation was detected in 26.4 % of Korean patients with CBF AML. The KIT D816 mutation demonstrated an unfavorable prognostic implication, particularly in the RUNX1/ RUNX1T1 subtype. [ABSTRACT FROM AUTHOR]

Juvenile myelomonocytic leukemia (JMML) is a rare hematologic malignancy in children. Hyperactivation of the Ras pathway from gene mutations is known to be the key culprit in the development of JMML. In this study, we investigated Ras pathway mutations and prognostic implication in Korean patients with JMML. A total of 22 Korean patients with JMML were recruited from two institutions (19 boys and three girls; median age, 17 months; range, 1-74 months). Hematologic and cytogenetic findings were reviewed. Mutation analyses involved PTPN11, KRAS, NRAS, and CBL genes by direct sequencing analyses (selected exons except in CBL). Survival analysis was performed by the Kaplan-Meier method. Cytogenetic and/or gene mutations were detected in 18 patients out of 22 (82%). Four patients (18%) had chromosomal abnormalities, with monosomy 7 being the most common. Seventeen (77%) had gene mutations. PTPN11 mutations were detected in 13 patients (59%). The patient heterozygous for c.854T>C had Noonan syndrome. NRAS and KRAS mutations were detected in two patients (9%) and one patient (5%), respectively. A homozygous CBL mutation was detected in one patient (5%; c.1228-2A>G). All mutations detected were previously reported mutations. Survival analyses suggested an unfavorable prognostic implication of PTPN11 mutation, albeit without a statistical significance. Collectively, the results from molecular genetics study and survival analyses suggested a relatively higher frequency and unfavorable prognostic implication of PTPN11 mutations in Korean patients with JMML. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is one of the most common types of leukemia. With the recent advances in sequencing technology and the growing body of knowledge on the genetics of AML, there is increasing concern about cancer predisposing germline mutations as well as somatic mutations. As familial cases sharing germline mutations are constantly reported, germline predisposition gene mutations in patients with AML are gaining attention. We performed genomic sequencing of Korean patients diagnosed with AML to identify the prevalence and characteristics of germline predisposition mutations. Among 180 patients, germline predisposition mutations were identified in 13 patients (13/180, 7.2%, eight adults and five children). Germline mutations of BLM, BRCA1, BRCA2, CTC1, DDX41, ERCC4, ERCC6, FANCI, FANCM, PALB2, and SBDS were identified. Most of the mutations are in genes involved in DNA repair and genomic stability maintenance. Patients harboring germline mutations tended to have earlier onset of AML (p = 0.005), however, the presence of germline mutations did not showed significant association with other clinical characteristics or treatment outcome. Since each mutation was rare, further study with a larger number of cases would be needed to establish the effect of the mutations. [ABSTRACT FROM AUTHOR]

Summary Recent benchmark studies have demonstrated the difficulties in obtaining accurate predictions of ligand binding conformations to comparative models of G-protein-coupled receptors. We have developed a data-driven optimization protocol, which integrates mutational data and structural information from multiple X-ray receptor structures in combination with a fully flexible ligand docking protocol to determine the binding conformation of AR231453, a small-molecule agonist, in the GPR119 receptor. Resulting models converge to one conformation that explains the majority of data from mutation studies and is consistent with the structure-activity relationship for a large number of AR231453 analogs. Another key property of the refined models is their success in separating active ligands from decoys in a large-scale virtual screening. These results demonstrate that mutation-guided receptor modeling can provide predictions of practical value for describing receptor-ligand interactions and drug discovery. [ABSTRACT FROM AUTHOR]