scholarly journals Whole Genome Sequencing and RNA Sequencing of 27 Patients with Persistent Polyclonal B-Cell Lymphocytosis Reveals a High Mutation Frequency/Overexpression of Lymphoma Associated Genes: Really a Benign Disorder?

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 924-924
Author(s):  
Anna Stengel ◽  
Alexander Höllein ◽  
Wolfgang Kern ◽  
Manja Meggendorfer ◽  
Claudia Haferlach ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Whole Genome Sequencing ◽  
Rna Sequencing ◽  
Genome Sequencing ◽  
Splice Site ◽  
Mutation Frequency ◽  
Whole Genome ◽  
Employment Equity ◽  
Equity Ownership

Abstract Background: Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare disorder, occurs almost exclusively in smoking women and is characterized by a chronic polyclonal lymphocytosis with circulating binucleated lymphocytes, clonal cytogenetic abnormalities involving chromosome 3, and chromosomal instability. Outcome of PPBL patients is mostly benign, but subsequent malignancies (non-Hodgkin´s lymphomas and solid tumors) were described. Potential molecular factors leading to their development are yet unclear. Aims: Detailed molecular genetic characterization of PPBL by whole genome sequencing (WGS) and RNA sequencing (RNAseq) in comparison to the well-characterized lymphoid malignancy CLL. Patient cohorts and methods: The total cohort comprised 27 PPBL (3 male, 24 female) and 250 CLL cases (163 male, 87 female). WGS was performed for all patients: 150bp paired-end reads where generated on Illumina HiseqX and NovaSeq 6000 machines (Illumina, San Diego, CA). A mixture genomic DNA from multiple anonymous donors was used as normal controls. To remove potential germline variants, each variant was queried against the gnomAD database, variants with global population frequencies >1% where excluded. Final analysis was performed only on protein-altering and splice-site variants. For further analysis, a virtual panel of 355 lymphoid genes was selected. All reported p-values are two-sided and were considered significant at p<0.05. For gene expression analysis, estimated gene counts were normalized applying Trimmed mean of M-values (TMM) normalization method and the resulting log2 counts per million (CPMs) were used as a proxy of gene expression in each sample. Genes were kept if they were expressed (> 5 CPM) in at least 66% of the samples. Genes with FDR (false discovery rate) < 0.05 and an absolute logFC > 1.5 were considered differentially expressed (DE). Results: Median age was 46 years for PPBL patients (range: 23-67 years) and 67 years for CLL patients (range: 39-94 years). Mean number of mutations per patient was 18 for PPBL and 20 for CLL. For both entities, the majority of mutations were missense mutations (88% in PPBL vs. 81% in CLL), followed by splice-site mutations (7% vs. 10%), other mutation types were only rarely detected. In PPBL, 42 genes were found to be mutated at a frequency of >15%, including ATM (22%), CREBBP (19%), NCOR2 (19%), AHNAK2 (15%), JAK3 (15%), NOTCH2 (15%) and TRAF1 (15%), all of which have been associated with a variety of cancers. Moreover, ATM, NOTCH2 and TRAF1 mutations were described before to be associated with lymphomas. In PPBL patients, mutations in TRAF1 and ATM as well as mutations in TRAF1 and NOTCH2 were found to be mutually exclusive. For CLL patients, 29 genes showed a mutation frequency of >15%, comprising ATM (26%), KMT2D (23%), NOTCH1 (23%), LRP1B (19%), TP53 (16%) and CREBBP (15%). Comparison of the mutation frequencies between the two entities revealed several genes with significant differences: whereas mutations in CKAP5 (11% vs. 2%, p=0.022), DNMT3A (11% vs. 3%, p=0.033), MAP2 (19% vs. 4%, p=0.009), ROBO1 (15% vs. 4%, p=0.046) and TRAF1 (15% vs. 2%, p=0.006) were found to be more frequent in PPBL cases compared to CLL cases, KMT2D (4% vs. 23%, p=0.014), TDRD6 (0% vs. 14%, p=0.032) and TP53 (4% vs. 16%, p=0.048) mutations were more abundantly detected in CLL patients. Moreover, NOTCH1 was mutated more frequently in CLL cases (7% vs. 23%, p=0.082), whereas mutated NOTCH2 (known to be frequently mutated in splenic marginal zone lymphoma), was more abundant in PPBL patients (15% vs. 6%, p=0.116), although both correlations were not statistically significant. Gene expression analyses by RNAseq revealed 337 genes to be differentially expressed between the entities. 207 genes were upregulated in PPBL, including PTPRK, CXCR1, BCL11B, CEPBA, CCR4 and MYC, whereas 130 genes were found to be upregulated in CLL cases, comprising ID3, BCL2, FGF2 and FLT1. Conclusions: 1) WGS analysis identifies high frequencies of cancer/lymphoma-associated gene mutations in PPBL, including mutated ATM, NOTCH2 and TRAF1. 2) Five genes showed a higher mutation frequency compared to CLL including TRAF1,DNMT3A, CKAP5 and MAP2. 3) Lymphoma associated genes (BCL11B and MYC) were overexpressed in PPBL vs CLL. 4) Taken together our results question PPBL as a benign entity and identify molecular markers that might contribute to development of subsequent malignancies. Disclosures Stengel: MLL Munich Leukemia Laboratory: Employment. Höllein:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Walter:MLL Munich Leukemia Laboratory: Employment. Hutter:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Comprehensive Analysis of MYC Translocations in Multiple Myeloma By Whole Genome Sequencing and Whole Transcriptome Sequencing

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1774-1774 ◽  
Author(s):  
Sonja Seliger ◽  
Verena Geirhos ◽  
Torsten Haferlach ◽  
Wolfgang Kern ◽  
Wencke Walter ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Genome Sequencing ◽  
Transcriptome Sequencing ◽  
Comprehensive Analysis ◽  
Whole Genome ◽  
Employment Equity ◽  
Whole Transcriptome Sequencing ◽  
Equity Ownership ◽  
Whole Transcriptome

Background 8q24 translocations leading to overexpression of MYC are an established prognostic marker in multiple myeloma (MM). Currently FISH (fluorescence in situ hybridization) on CD138+ enriched cell population is the standard diagnostic approach to evaluate the presence of 8q24 translocations. Due to the heterogeneity of breakpoints and technical issues the design of FISH probes is challenging and so far no single FISH assay is capable of detecting each translocation. Aims (1) Evaluation of the frequency of 8q24 translocations in MM by whole genome sequencing (WGS). (2) Determination of the breakpoints on 8q24 and partners. (3) Correlation of WGS data with FISH and MYC expression determined by whole transcriptome sequencing (WTS). Patient cohort and methods CD138+ cell fractions were selected by MACS from bone marrow aspirate samples of 264 patients diagnosed with MM. FISH, WGS and WTS were performed in all cases. For WGS, 151bp paired-end sequences where generated on NovaSeq 6000 machines (Illumina, San Diego, CA). All reported p-values are two-sided and were considered significant at p<0.05. For gene expression (GE) analysis by WTS, estimated gene counts were normalized and the resulting log2 counts per million were used as a proxy of gene expression in each sample. For artefact exclusion, structural variants were checked against 4386 cases covering the spectrum of hematological malignancies. Results In 91/264 (34%) of cases, at least one rearrangement involving the MYC locus (MYCr) was detected by WGS. In 18 of these samples (20%), >1 MYCr was present (114 MYCr in total). Out of these 91 patients, in 32 (35%) the MYCr had been identified by FISH, in 46 cases (51%) it was not detected due to the heterogeneity of breakpoints, while in 13 (14%) patients FISH could not be evaluated (e.g. due to insufficient patient material). Of the 114 MYCr encountered in WGS, 42 involved one of the immunoglobulin loci (IGH n=25, IGK n=9, IGL n=8). The remaining 72 MYCr involved other rare partners. In 29 of these rearrangements, as well as in four complex rearrangements involving IGH or IGK, recurrent rare partners were identified, comprising 1p12/FAM46C (n=6), 6p24.3/BMP6 (n=10), 6q21/FOXO3 (n=4), 7p21.3 (n=3), 11q13/CCND1 (n=5), 20q11.22 (n=5). 43 MYCr involved non-recurrent (single) rare partners, for 4 of these a MYCr was also detected by FISH. The MYCr detected were rather complex: only 34 (30%) showed a simple reciprocal translocation (IGH n=7, IGL n=2, IGK n=4, rare partners n=21), 60 (53%) showed more complex rearrangements (IGH n=12, IGL n=4, IGK n=2, rare partners n=42) and in 20 cases (18%) at least one additional chromosome was involved (IGH n=6, IGL n=3, IGK n=2, rare partners n=9). In 80% of MYCr, breakpoints were located between genomic positions 128.203.605 and 129.375.490 encompassing the pre-described MYC surrounding locus PVT1. IGH-MYC rearrangements showed a tendency to cluster towards the centromere. MYCr involving rare partners showed the broadest breakpoint spectrum and clustered in both directions of the hotspot (Fig 1A). Regarding expression of MYC, all cases showed an overexpression (median GE: 6.9 vs 4.5 in normal controls). Median GE was similar in cases with Ig partners (IGH: 7.1, IGL: 6.7, IGK: 6.6) and non Ig partners (6.8) and also in cases with MYCr detected by FISH (7.0) and cases in which it was not detected by FISH (6.5). Analysis of additional chromosomal aberrations revealed that hyperdiploidy was significantly more frequent in MYCr (n=68/91, 75% vs n=76/173, 44%; p=0.001), while t(11;14) was found significantly less frequent (n=11/91, 12% vs n=49/173, 28%; p=0.003) (Fig 1B). No associations were found between MYCr and other frequent chromosomal abnormalities. Furthermore, molecular mutations frequently occurring in MM (ATM, BRAF, KRAS, NRAS, TP53, IRF4) were analyzed, revealing that patients with MYCr were significantly less frequently associated with mutations in the IRF4 gene (MYCr patients n=1/91; non-MYCr patients n=13/173; p =0.028) (Fig 1C). Conclusions (1) WGS detects ~3x more MYCr compared to FISH. (2) The complexity on the genomic level of MYCr is high, therefore the detection with targeted assays is limited while WGS allows a more comprehensive analysis. (3) MYC expression in cases with MYCr with non Ig partners is comparably high as for Ig-MYC translocations. (4) MYCr are associated with hyperdiploidy, whereas t(11;14) and IRF4 mutations were detected at a lower frequency. Disclosures Seliger: MLL Munich Leukemia Laboratory: Employment. Geirhos:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Walter:MLL Munich Leukemia Laboratory: Employment. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Baer:MLL Munich Leukemia Laboratory: Employment. Stengel:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

scholarly journals The crest phenotype in domestic chicken is caused by a 197 bp duplication in the intron of HOXC10

2021 ◽  
Author(s):  
Jingyi Li ◽  
Mi-Ok Lee ◽  
Brian W Davis ◽  
Ping Wu ◽  
Shu-Man Hsieh-Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Whole Genome Sequencing ◽  
Diagnostic Test ◽  
Genome Sequencing ◽  
Ectopic Expression ◽  
Body Region ◽  
Whole Genome ◽  
Dorsal Skin ◽  
Conserved Sequence ◽  
Evolutionarily Conserved

Abstract The Crest mutation in chicken shows incomplete dominance and causes a spectacular phenotype in which the small feathers normally present on the head are replaced by much larger feathers normally present only in dorsal skin. Using whole genome sequencing, we show that the crest phenotype is caused by a 197 bp duplication of an evolutionarily conserved sequence located in the intron of HOXC10 on chromosome 33. A diagnostic test showed that the duplication was present in all 54 crested chickens representing eight breeds and absent from all 433 non-crested chickens representing 214 populations. The mutation causes ectopic expression of at least five closely linked HOXC genes, including HOXC10, in cranial skin of crested chickens. The result is consistent with the interpretation that the crest feathers are caused by an altered body region identity. The upregulated HOXC gene expression is expanded to skull tissue of Polish chickens showing a large crest often associated with cerebral hernia, but not in Silkie chickens characterized by a small crest, both homozygous for the duplication. Thus, the 197 bp duplication is required for the development of a large crest and susceptibility to cerebral hernia because only crested chicken show this malformation. However, this mutation is not sufficient to cause herniation because this malformation is not present in breeds with a small crest, like Silkie chickens.

scholarly journals E. coli NF73-1 Isolated From NASH Patients Aggravates NAFLD in Mice by Translocating Into the Liver and Stimulating M1 Polarization

2020 ◽  
Vol 10 ◽  
Author(s):  
Yifan Zhang ◽  
Weiwei Jiang ◽  
Jun Xu ◽  
Na Wu ◽  
Yang Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Comparative Genomics ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Normal Diet ◽  
Specific Gene ◽  
Whole Genome ◽  
Metabolic Switch ◽  
M1 Macrophages ◽  
E Coli

ObjectiveThe gut microbiota is associated with nonalcoholic fatty liver disease (NAFLD). We isolated the Escherichia coli strain NF73-1 from the intestines of a NASH patient and then investigated its effect and underlying mechanism.Methods16S ribosomal RNA (16S rRNA) amplicon sequencing was used to detect bacterial profiles in healthy controls, NAFLD patients and NASH patients. Highly enriched E. coli strains were cultured and isolated from NASH patients. Whole-genome sequencing and comparative genomics were performed to investigate gene expression. Depending on the diet, male C57BL/6J mice were further grouped in normal diet (ND) and high-fat diet (HFD) groups. To avoid disturbing the bacterial microbiota, some of the ND and HFD mice were grouped as “bacteria-depleted” mice and treated with a cocktail of broad-spectrum antibiotic complex (ABX) from the 8th to 10th week. Then, E. coli NF73-1, the bacterial strain isolated from NASH patients, was administered transgastrically for 6 weeks to investigate its effect and mechanism in the pathogenic progression of NAFLD.ResultsThe relative abundance of Escherichia increased significantly in the mucosa of NAFLD patients, especially NASH patients. The results from whole-genome sequencing and comparative genomics showed a specific gene expression profile in E. coli strain NF73-1, which was isolated from the intestinal mucosa of NASH patients. E. coli NF73-1 accelerates NAFLD independently. Only in the HFD-NF73-1 and HFD-ABX-NF73-1 groups were EGFP-labeled E. coli NF73-1 detected in the liver and intestine. Subsequently, translocation of E. coli NF73-1 into the liver led to an increase in hepatic M1 macrophages via the TLR2/NLRP3 pathway. Hepatic M1 macrophages induced by E. coli NF73-1 activated mTOR-S6K1-SREBP-1/PPAR-α signaling, causing a metabolic switch from triglyceride oxidation toward triglyceride synthesis in NAFLD mice.ConclusionsE. coli NF73-1 is a critical trigger in the progression of NAFLD. E. coli NF73-1 might be a specific strain for NAFLD patients.

scholarly journals Chromoplexy and Chromothripsis Are Important Prognostically in Myeloma and Deregulate Gene Function By a Range of Mechanisms

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3767-3767 ◽  
Author(s):  
Cody Ashby ◽  
Eileen M Boyle ◽  
Brian A Walker ◽  
Michael A Bauer ◽  
Katie Rose Ryan ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Genome Sequencing ◽  
Gene Function ◽  
Research Funding ◽  
Whole Genome ◽  
Structural Variants ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Research Grant

Background: Structural variants are key recurrent molecular features of myeloma (MM) with two types of complex rearrangement, chromoplexy and chromothripsis, having been described recently. The contribution of these to MM prognosis, rapid changes in clinical behavior and punctuated evolution is currently unknown as is the mechanism by which they deregulate gene function. Methods: We analyzed two sets of newly diagnosed MM data: 85 cases with phased whole genome sequencing; and 812 cases from CoMMpass where long-insert whole-genome sequencing was available. Patient derived xenografts from five MM cases were used to generate epigenetic maps for the histone marks, BRD4, MED1, H3K27Ac, H3K4me1, H3K4me3, H3K9me3, H3K36me3 and H3K27me3. Results: In the 10X data the median number of structural events per case was 25 (range 1 - 182); with a median of 14 intra-chromosomal events (range 1 - 179; P<0.001) and 7 inter-chromosomal events (range 0 - 29). Structural events were seen most frequently on chromosomes 14 (64%), 8 (53%), 1 (44%) and 6 (42%). Complex chromosomal rearrangements involving 3 or more chromosomal sites were seen in 46%, 4 or more sites in 20%, 5 or more in 10% and 6 or more in 5% of samples. There were significantly more structural events in the t(4;14) subgroup compared to the t(11;14) subgroup. Significantly more events were also seen in the bi-allelically inactivated TP53 cases. Using an elbow test defined cutoff, we identified cases with high structural variant load in 10% of cases. Chromoplexy called by "Chainfinder" was seen in 18% of cases. Chromothripsis called by "Shatterseek" was seen in 9% of cases. Cases with a high structural load alone were not associated with an adverse outcome whereas cases with chromoplexy or chromothripsis were associated with adverse PFS and OS, p=0.001. A new high-risk subgroup comprising approximately 5% of cases was identified with chromoplexy, chromothripsis and a high structural load. Gene set enrichment analysis of cases with chromoplexy and chromothripsis showed an excess of MYC, E2F and G2M targets, and a reduction in RAS signaling. Interferon a and g responses, an excess of TP53 and reduction in TRAF3 mutations was associated predominantly with chromothripsis. How chromoplexy and chromothripsis are tolerated by the cell is unknown and the association with the cGAS/STING response is further being explored. To determine how chromoplexy may deregulate multiple genes we identified the full spectrum of structural variants to the immunoglobulin (Ig) and non-Ig loci. A range of genes are deregulated by Ig loci including MAP3K14 at a frequency of 2% confirming the importance of non-canonical NFkB signaling. A novel intra-chromosomal rearrangement to ZFP36L1 was upregulated in 10% of cases but was not prognostic. Gene upregulation by non-Ig super enhancers is frequent and targets include PAX5, GLI3, CD40, NFKB1, MAP3K14, LRRC37A, LIPG, PHLDA3, ZNF267, CENPF, SLC44A2, MIER1, SOX30, TMEM258, PPIL1, and BUB3. The topologically associating domain (TADs) containing super enhancers bringing about gene deregulation include TXNDC5, FOXO3, FCHSD2, SP2, FAM46C, CACNA1C, TLCD2 and PIK3C2G. These super enhancers frequently contain important MM genes, the coding sequence of which are disrupted by the rearrangement and could contribute to the clinical phenotype. Accurately reconstructing the structure of the complex rearrangements will allow us to identify the mechanism of gene deregulation and to distinguish between either gene stacking, receptor stacking or both. Conclusions: Upregulation of gene expression by super enhancer rearrangement is a major mechanism of gene deregulation in MM and complex structural events contribute significantly to adverse prognosis by a range of mechanisms as well as simple gene overexpression. Disclosures Boyle: Amgen, Abbvie, Janssen, Takeda, Celgene Corporation: Honoraria; Amgen, Janssen, Takeda, Celgene Corporation: Other: Travel expenses. Walker:Celgene: Research Funding. Thakurta:Celgene: Employment, Equity Ownership. Flynt:Celgene Corporation: Employment, Equity Ownership. Davies:Amgen, Celgene, Janssen, Oncopeptides, Roche, Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Consultant/Advisor; Janssen, Celgene: Other: Research Grant, Research Funding. Morgan:Amgen, Roche, Abbvie, Takeda, Celgene, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Other: research grant, Research Funding.

scholarly journals Whole genome sequencing analysis of high confidence variants of B-cell lymphoma in Canis familiaris

PLoS ONE ◽  
2020 ◽  
Vol 15 (8) ◽  
pp. e0238183
Author(s):  
Alana Sparks ◽  
J. Paul Woods ◽  
Dorothee Bienzle ◽  
Geoffrey A. Wood ◽  
Brenda Lynn Coomber
Keyword(s):  
B Cell ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Cell Lymphoma ◽  
Canis Familiaris ◽  
B Cell Lymphoma ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
High Confidence

scholarly journals Rapid Whole-genome Sequencing of Zika Viruses using Direct RNA Sequencing

2019 ◽  
Vol 49 (3) ◽  
pp. 115
Author(s):  
Jung Heon Kim ◽  
Jiyeon Kim ◽  
Bon-Sang Koo ◽  
Hanseul Oh ◽  
Jung-Joo Hong ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Rna Sequencing ◽  
Genome Sequencing ◽  
Whole Genome

Discovery of Novel Recurrent Mutations in Childhood Early T-Cell Precursor Acute Lymphoblastic Leukemia by Whole Genome Sequencing - a Report From the St Jude Children's Research Hospital - Washington University Pediatric Cancer Genome Project

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 68-68
Author(s):  
Jinghui Zhang ◽  
Li Ding ◽  
Linda Holmfeldt ◽  
Gang Wu ◽  
Susan L. Heatley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Lymphoblastic Leukemia ◽  
Whole Genome ◽  
Structural Variants ◽  
Cell Precursor ◽  
Recurrent Mutations

Abstract Abstract 68 Early T-cell precursor acute lymphoblastic leukemia (ETP ALL) is characterized by an immature T-lineage immunophenotype (cCD3+, CD1a-, CD8- and CD5dim) aberrant expression of myeloid and stem cell markers, a distinct gene expression profile and very poor outcome. The underlying genetic basis of this form of leukemia is unknown. Here we report results of whole genome sequencing (WGS) of tumor and normal DNA from 12 children with ETP ALL. Genomes were sequenced to 30-fold haploid coverage using the Illumina GAIIx platform, and all putative somatic sequence and structural variants were validated. The frequency of mutations in 43 genes was assessed in a recurrence cohort of 52 ETP and 42 non-ETP T-ALL samples from patients enrolled in St Jude, Children's Oncology Group and AEIOP trials. Transcriptomic resequencing was performed for two WGS cases, and whole exome sequencing for three ETP ALL cases in the recurrence cohort. We identified 44 interchromosomal translocations (mean 4 per patient, range 0–12), 32 intrachromosomal translocations (mean 3, 0–7), 53 deletions (mean 4, 0–10) and 16 insertions (mean 1, 0–5). Three cases exhibited a pattern of complex rearrangements suggestive of a single cellular catastrophe (“chromothripsis”), two of which had mutations targeting mismatch and DNA repair (MLH3 and DCLRE1C). While no single chromosomal alteration was present in all cases, 10 of 12 ETP ALLs harbored chromosomal rearrangements, several of which involved complex multichromosomal translocations and resulted in the expression of chimeric in-frame novel fusion genes disrupting hematopoietic regulators, including ETV6-INO80D, NAP1L1-MLLT10, RUNX1-EVX1 and NUP214-SQSTM1, each occurring in a single case. An additional ETP case with the ETV6-INO80D fusion was identified in the recurrence cohort. Additionally, 51% of structural variants had breakpoints in genes, including those with roles in hematopoiesis and leukemogenesis, and genes also targeted by mutation in other cases (MLH3, SUZ12, RUNX1). We identified a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling in ETP ALL (67.2% of ETP compared to 19% of non-ETP T-ALL) including NRAS (17%), FLT3 (14%), JAK3 (9%), SH2B3 (or LNK; 9%), IL7R (8%), JAK1 (8%), KRAS (3%), and BRAF (2%). Seven cases (5 ETP, 2 non-ETP) harbored in frame insertion mutations in the transmembrane domain of IL7R, which were transforming when expressed in the murine cell lines, and resulted in enhanced colony formation when expressed in primary murine hematopoietic cells. The IL7R mutations resulted in constitutive Jak-Stat activation in these cell lines and primary leukemic cells expressing these mutations. Fifty-eight percent of ETP cases (compared to 17% of non-ETP cases) harbored mutations known or predicted to disrupt hematopoietic and lymphoid development, including ETV6 (33%), RUNX1 (16%), IKZF1 (14%), GATA3 (10%), EP300 (5%) and GATA2 (2%). GATA3 regulates early T cell development, and mutations in this gene were observed exclusively in ETP ALL. The mutations were commonly biallelic, and were clustered at R276, a residue critical for binding of GATA3 to DNA. Strikingly, mutations disrupting chromatin modifying genes were also highly enriched in ETP ALL. Genes encoding the the polycomb repressor complex 2 (EZH2, SUZ12 and EED), that mediates histone 3 lysine 27 (H3K27) trimethylation were deleted or mutated in 42% of ETP ALL compared to 12% of non-ETP T-ALL. In addition, alterations of the H3K36 trimethylase SETD2 were observed in 5 ETP cases, but not in non-ETP ALL. We also identified recurrent mutations in genes that have not previously been implicated in hematopoietic malignancies including RELN, DNM2, ECT2L, HNRNPA1 and HNRNPR. Using gene set enrichment analysis we demonstrate that the gene expression profile of ETP ALL shares features not only with normal human hematopoietic stem cells, but also with leukemic initiating cells (LIC) purified from patients with acute myeloid leukemia (AML). These results indicate that mutations that drive proliferation, impair differentiation and disrupt histone modification cooperate to induce an aggressive leukemia with an aberrant immature phenotype. The similarity of the gene expression pattern with that observed in the LIC of AML raises the possibility that myeloid-directed therapies might improve the outcome of ETP ALL. Disclosures: Evans: St. Jude Children's research Hospital: Employment, Patents & Royalties; NIH & NCI: Research Funding; Aldagen: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Single-cell whole-genome sequencing reveals the functional landscape of somatic mutations in B lymphocytes across the human lifespan

2019 ◽  
Author(s):  
Lei Zhang ◽  
Xiao Dong ◽  
Moonsook Lee ◽  
Alexander Y. Maslov ◽  
Tao Wang ◽  
...  
Keyword(s):  
B Cell ◽  
Whole Genome Sequencing ◽  
Single Cell ◽  
B Lymphocytes ◽  
Genome Sequencing ◽  
Somatic Mutations ◽  
Somatic Hypermutation ◽  
Whole Genome ◽  
Healthy Individuals ◽  
Human Lifespan

Introductory paragraphThe accumulation of mutations in somatic cells have been implicated as a cause of ageing since the 1950s1,2. Yet, attempts to establish a causal relationship between somatic mutations and ageing have been constrained by the lack of methods to directly identify mutational events in primary human tissues. Here we provide detailed, genome-wide mutation frequencies and spectra of human B lymphocytes from healthy individuals across the entire human lifespan, from newborns to centenarians, using a recently developed, highly accurate single-cell whole-genome sequencing method3. We found that the number of somatic mutations increases from <500 per cell in newborns to >3,000 per cell in centenarians. We discovered mutational hotspot regions, some of which, as expected, located at immunoglobulin genes associated with somatic hypermutation. B cell-specific mutation signatures were observed associated with development, ageing or somatic hypermutation (SHM). The SHM signature strongly correlated with the signature found in human chronic lymphocytic leukemia and malignant B-cell lymphomas4, indicating that even in B cells of healthy individuals the potential cancer-causing events are already present. We also identified multiple mutations in sequence features relevant to cellular function, i.e., transcribed genes and gene regulatory regions. Such mutations increased significantly during ageing, but only at approximately half the rate of the genome average, indicating selection against mutations that impact B cell function. This first full characterization of the landscape of somatic mutations in human B lymphocytes indicates that spontaneous somatic mutations accumulating with age can be deleterious and may contribute to both the increased risk for leukemia and the functional decline of B lymphocytes in the elderly.

scholarly journals WGS and RNA Studies Diagnose Noncoding DMD Variants in Males With High Creatine Kinase

2021 ◽  
Vol 7 (1) ◽  
pp. e554
Author(s):  
Leigh B. Waddell ◽  
Samantha J. Bryen ◽  
Beryl B. Cummings ◽  
Adam Bournazos ◽  
Frances J. Evesson ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Western Blot ◽  
Whole Genome Sequencing ◽  
Rna Sequencing ◽  
Genome Sequencing ◽  
Premature Stop Codon ◽  
Clinical Severity ◽  
Whole Genome ◽  
Wild Type ◽  
Quantitative Western Blot

ObjectiveTo describe the diagnostic utility of whole-genome sequencing and RNA studies in boys with suspected dystrophinopathy, for whom multiplex ligation-dependent probe amplification and exomic parallel sequencing failed to yield a genetic diagnosis, and to use remnant normal DMD splicing in 3 families to define critical levels of wild-type dystrophin bridging clinical spectrums of Duchenne to myalgia.MethodsExome, genome, and/or muscle RNA sequencing was performed for 7 males with elevated creatine kinase. PCR of muscle-derived complementary DNA (cDNA) studied consequences for DMD premessenger RNA (pre-mRNA) splicing. Quantitative Western blot was used to determine levels of dystrophin, relative to control muscle.ResultsSplice-altering intronic single nucleotide variants or structural rearrangements in DMD were identified in all 7 families. Four individuals, with abnormal splicing causing a premature stop codon and nonsense-mediated decay, expressed remnant levels of normally spliced DMD mRNA. Quantitative Western blot enabled correlation of wild-type dystrophin and clinical severity, with 0%–5% dystrophin conferring a Duchenne phenotype, 10% ± 2% a Becker phenotype, and 15% ± 2% dystrophin associated with myalgia without manifesting weakness.ConclusionsWhole-genome sequencing relied heavily on RNA studies to identify DMD splice-altering variants. Short-read RNA sequencing was regularly confounded by the effectiveness of nonsense-mediated mRNA decay and low read depth of the giant DMD mRNA. PCR of muscle cDNA provided a simple, yet informative approach. Highly relevant to genetic therapies for dystrophinopathies, our data align strongly with previous studies of mutant dystrophin in Becker muscular dystrophy, with the collective conclusion that a fractional increase in levels of normal dystrophin between 5% and 20% is clinically significant.

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