scholarly journals Whole-Exome Sequencing Identifies Germline IDH2 and IDH3 mutations That Predispose to Myeloid Neoplasms

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1405-1405 ◽  
Author(s):  
Remco Molenaar ◽  
Srinivasa Reddy Sanikommu ◽  
Bhumika J. Patel ◽  
Bartlomiej Przychodzen ◽  
Cornelis J van Noorden ◽  
...  

Abstract Background: Somatic mutations in isocitrate dehydrogenases 1 and 2 (IDH1/2MT) occur in up to 20% of certain types of myeloid neoplasms, chiefly MDS, MDS/MPN overlap and AML. These mutations induce a metabolic rewiring of cancer cells that affects alpha-ketoglutarate (aKG)-dependent dioxygenases such as TET2 DNA demethylases and Jumanji histone demethylases, which leads to global DNA and chromatin hypermethylation and leukemogenesis. In addition to somatic IDH1/2MT, germline IDH1/2MT occur in the context of Ollier and Maffucci syndromes which predispose to cartilaginous tumors and D 2HG aciduria, which predisposes to brain tumors. We hypothesized that germline mutations in IDH1/2 or the functionally related IDH3 may predispose to myeloid neoplasms. Methods: From 409 patients with MDS, MPN or AML, tumor samples from the myeloid compartment and germline samples from CD3+ lymphocytes were subjected to whole-exome sequencing. Myeloid cells were adhered to microscopy slides and maximal IDH3, IDH1/2 and, glucose-6-phosphate dehydrogenase (G6PD) glutamate dehydrogenase (GDH) activity was determined using quantitative enzyme cytochemistry. Results: In 409 patients with myeloid diseases, we found 8 patients with germline variants in IDH2 or IDH3. Combined, these variants occur more frequently in these 409 patients with myeloid neoplasms than in the general population (OR = 4.05, P=.0024), suggesting that germline IDH2/3MT predispose for myeloid diseases (Table 1). Of note, germline IDH2/3MT were completely mutually exclusive with somatic TET2MT, suggesting overlapping functions. Notably, all but one of these variants were indicated by two independent software programs to be deleterious for the enzymatic activity. To validate this, we determined maximal IDH3 activity in myeloid cells derived from a 47-year old AML patient with a germline IDH3MT (c.G626A, p.G209E) (and family history of leukemia) and her sister with IDH3WT. Maximal IDH3 activity was downregulated in the IDH3MT sample, while maximal IDH1/2, G6PD and GDH activity were unchanged (Fig. 1). 1 patient had a family history of MDS and 3 patients had a family history of colon, prostrate, gastric, lung and head and neck carcinoma in multiple family members. One patient had 4 family members affected with different cancers. The high age of the affected patients suggest that although germline IDH2/3MT may predispose to myeloid neoplasms, the development of disease occurs slowly. Discussion: Whereas somatic IDH2MT are common in MDS and other myeloid neoplasms, somatic IDH3MT are not frequently observed, nor in myeloid neoplasms, nor in other types of cancer that are regularly affected by IDH1/2MT. We show that deleterious germline IDH2/3MT may predispose to myeloid neoplasms and we postulate that this may occur via decreases in IDH2/3 activity. IDH3G209E is deleterious for IDH3 enzymatic function and may decrease intracellular aKG levels. This will restrict the function of aKG-dependent dioxygenases such as TET2 and Jumonji and mimic somatic IDH1/2MT and somatic inactivating TET2MT. This suggests that IDH1/2/3 are key enzymes and aKG is a central metabolite in maintaining normal function in myeloid cells. Given the family histories of 5/8 of the affected patients, screenings for germline IDH2/3 variants may reveal novel recurring IDH2/3MT that relate to various types of cancer. Representative photomicrographs of primary IDH3G209E MDS and IDH3WT myeloid cells after staining IDH3 activity in the presence of various isocitrate concentrations, IDH2 activity (1 mM isocitrate) and GDH activity (5 mM glutamate) using quantitative enzyme cytochemistry. The conversion of colorless tetrazolium salt to the purple formazan directly reflects enzyme activity thus darker cells have a higher maximal activity of the investigated enzyme. Table 1. Clinical characteristics from 6 patients with germline IDH2/3MT for which clinical information was available. Patient ID Age Diagnosis Gender OS (months) Variant SNP nr Occurrence in general population 1 50 RCMD F 23 IDH2T495M rs118053940 0,004848 2 66 CMML-1 M 46 IDH3AR360C rs116374996 0,004161 3 49 RAEB-1 F 16 IDH3BR359W rs377682152 0,000154 4 70 RCMD M 67 IDH2T495M rs118053940 0,004848 5 76 MDS-U F 17 IDH3BR334W rs374613588 0,00008 6 75 sAML M 5 IDH2R261H rs118101777 0,00177 Figure 1. Germline IDH3G209E mutation decreases maximal IDH3 activity, but not maximal IDH2 or GDH activity. Figure 1. Germline IDH3G209E mutation decreases maximal IDH3 activity, but not maximal IDH2 or GDH activity. Disclosures No relevant conflicts of interest to declare.

2018 ◽  
Author(s):  
Brooke N. Wolford ◽  
Whitney E. Hornsby

ABSTRACTBackgroundThoracic aortic dissection is an emergent life-threatening condition. Routine screening for genetic variants causing thoracic aortic dissection is not currently performed for patients or their family members.MethodsWe performed whole exome sequencing of 240 patients with thoracic aortic dissection (n=235) or rupture (n=5) and 258 controls matched for age, sex, and ancestry. Blinded to case-control status, we annotated variants in 11 genes for pathogenicity.ResultsTwenty-four pathogenic variants in 6 genes (COL3A1, FBN1, LOX, PRKG1, SMAD3, TGFBR2) were identified in 26 individuals, representing 10.8% of aortic cases and 0% of controls. Among dissection cases, we compared those with pathogenic variants to those without and found that pathogenic variant carriers had significantly earlier onset of dissection (41 vs. 57 years), higher rates of root aneurysm (54% vs. 30%), less hypertension (15% vs. 57%), lower rates of smoking (19% vs. 45%), and greater incidence of aortic disease in family members. Multivariable logistic regression showed significant risk factors associated with pathogenic variants are age <50 [odds ratio (OR) = 5.5; 95% CI: 1.6-19.7], no history of hypertension (OR=5.6; 95% CI: 1.4-22.3) and family history of aortic disease (mother: OR=5.7; 95% CI: 1.4-22.3, siblings: OR=5.1; 95% CI 1.1-23.9, children: OR=6.0; 95% CI: 1.4-26.7).ConclusionsClinical genetic testing of known hereditary thoracic aortic dissection genes should be considered in patients with aortic dissection, followed by cascade screening of family members, especially in patients with age-of-onset of aortic dissection <50 years old, family history of aortic disease, and no history of hypertension.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Stephanie M Ware ◽  
Steven E Lipshultz ◽  
Steven D Colan ◽  
Ling Shi ◽  
Charles E Canter ◽  
...  

Introduction: Pediatric cardiomyopathies are genetically heterogeneous diseases with high risk of death or cardiac transplant. Despite progress in identifying causes, the majority of cases remain idiopathic. Currrently, genetic testing is not performed in all children with cardiomyopathy. Gene identification leads to better individual risk stratification and has the potential to stimulate the development of therapies based on the underlying mutation. The aim of this study is to identify genetic mutations in pediatric cardiomyopathy patients using whole exome sequencing. Hypothesis: Sarcomeric mutations are under-diagnosed causes of all forms of cardiomyopathy in children. Methods: Probands with cardiomyopathy were recruited from 11 institutions. Results of clinical genetic testing prior to enrollment were collected. Whole exome sequencing was performed and mutations were identified in 35 genes currently available on clinical genetic testing panels. Results: The initial 154 probands subjected to exome included 78 patients with DCM, 43 with HCM, 14 with RCM, and 19 with LVNC, mixed, or unknown types. Familial disease was present in 38% and the remainder were idiopathic. Twenty-seven percent had positive clinical genetic testing prior to enrollment. Exome testing identified mutations in 38 subjects who had not had clinical testing, increasing the cohort positive testing rate to 55% (DCM, 34.6%; HCM, 74.4%; RCM, 71.4%). Forty-five percent of subjects with no family history of disease had an identifiable mutation. Conclusions: Pediatric cardiomyopathy patients have a high incidence of mutations that can be identified by clinically available genetic testing. Lack of a family history of cardiomyopathy was not predictive of normal genetic testing. These results support the broader use of genetic testing in pediatric patients with all functional phenotypes of cardiomyopathy to identify disease causation allowing better family risk stratification.


EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
E Polyakova ◽  
N Shcherbakova

Abstract Introduction. Sick sinus syndrome (SSS) and atrioventricular block (AVB) are life-threatening cardiac arrhythmias, that sometimes can manifest itself with syncope and needs a pacemaker implantation even in children. Sometimes, SSS and AVB are accompanied by structural heart diseases such as septal defects, cardiomyopathies, but often the heart is structurally normal. Some genes associated with bradyarrhythmias are well known. At the same time, the etiology of the SSS is unidentified and may be genetic caused in 50% of patients with SSS. There are no studies on the prevalence of with bradyarrhythmia-associated mutations in children. The purpose of our work is to identify and study the types of mutations associated with SSS and AVB in children. Methods. We included in the study 15 patients (27% boys) with severe SSS and AVB, from the database of the Russian Pediatric Arrhythmia Center. 11 were the probands and 4 - family members.  Personal and family history, physical examination, including ECG, stress test, Holter monitoring, ECHO and other tests, and whole exome sequencing were made. The average age was 14.1 ± 4.5 (from 2 to 17). Results.  In 30% (5 pts) there was the combination of with bradyarrhythmias and structural heart disease. 7 pts (47%) had syncope, 4 pacemakers were implanted. 10 children (67%) had the genetic variants of genes associated with SSS and AVB: SCN5A, TNNI3K, KCNA5, TRPM4, ANK2 and others. Family history of cardiac diseases was positive in 5 probands; 2 probands had family members with implanted pacemakers. In 3 pts were likely pathogenic variants and in 7 pts - variants of unknown significance found. Conclusion.  We found the genetic cause of bradyarrhythmias in 67% of children. Further research and larger patient samples are required to study the prevalence of genetic types of and show the correlation of the genotype with the clinical prognosis. In addition, our work will enable practitioners to identify children from families with family forms of SSS, AVB and sudden cardiac death. Further research can help us determine the criteria for selecting children for genetic testing.


2021 ◽  
Vol 10 (13) ◽  
pp. 2810
Author(s):  
P. V. AshaRani ◽  
Syidda Amron ◽  
Noor Azizah Bte Zainuldin ◽  
Sumanty Tohari ◽  
Alvin Y. J. Ng ◽  
...  

Genetics intersects with environmental, cultural, and social factors in the development of addictive disorders. This study reports the feasibility of whole-exome sequencing of trios (subject and two family members) to discover potential genetic variants in the development of substance use disorders (SUD). Family trios were recruited from the National Addictions Management Service in Singapore during the 2016–2018 period. Recruited subjects had severe alcohol use disorder (AUD) or opioid use disorder (OUD), with nicotine dependence (ND) and a family history of addictive disorders. Demographic characteristics and severity of addiction were captured. Whole-exome sequencing (WES) and analysis were performed on salivary samples collected from the trios. WES revealed variants in several genes in each individual and disruptive protein mutations in most. Variants were identified in genes previously associated with SUDs, such as Pleckstrin homology domain-containing family M member 3 (PLEKHM3), coiled-coil serine-rich protein 1 (CCSER1), LIM and calponin homology domains-containing protein 1 (LIMCH1), dynein axonemal heavy chain 8 (DNAH8), and the taste receptor type 2 member 38 (TAS2R38) involved in the perception of bitterness. The feasibility study suggests that subjects with a severe addiction profile, polysubstance use, and family history of addiction may often harbor gene variants that may predispose them to SUDs. This study could serve as a model for future precision medicine-based personalized interventional strategies for behavioral addictions and SUDs and for the discovery of potentially pathogenic genetic variants.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A209-A209
Author(s):  
Junyu He ◽  
Zhihong Liao

Abstract Background: Osteogenesis imperfecta (OI) is a rare hereditary connective tissue disease. It is mainly associated with pathogenic variants in COL1A1 or COL1A2. Patients with OI usually have repeated history of bone fractures. Besides, osteogenesis imperfecta is associated with some cardiovascular complications, such as aortic and mitral valve dysfunction, aneurysm and aortic dissection. But the relationship between these diseases has not been well studied. Case Presentation: A 55-year-old man was admitted to our hospital mainly due to “dizziness for 2 hours”. He had a 4-month history of hypertension and a history of smoking for more than 20 years. He had no history of drinking alcohol. He had hunchback and O-type legs. Besides, the patient and some of his relatives had a history of repeated brittle fractures,which was considered as “osteogenesis imperfecta”. The clinical manifestation of OI in this family varies to a certain extent, from simple tooth disintegration to severe fracture deformity. The most serious patient of his family was unable to walk. CT and MRI revealed multiple systemic arteriosclerosis, including vertebral artery, posterior inferior cerebellar artery, cervical artery, and bilateral cerebellar multiple lacunar cerebral infarction. The blood sample of the patient was tested by whole exome sequencing, and the saliva samples of the patient’s family members were tested by Sanger sequencing. A mutation c.3159 + 2T &gt; A was detected in COL1A2 gene associated with OI, also found in the other affected family members, which had not been reported before. It was a segregating mutation in the family. The clinical severity of the family members was heterogeneous. Discussion: This case is worth learning from the following aspects: 1. A pathogenic heterozygous mutation, c.3159 + 2T &gt; A was detected in COL1A2 gene in the patient with OI, which is not reported in previous cases of OI. 2. The clinical manifestation of OI in this family varies to a certain extent, from simple tooth disintegration to severe fracture deformity. The most serious patient of his family was unable to walk. It presented the clinical heterogeneity of OI. Further basic researh on the mutation site of related gene of OI are needed. 3. We found the possibility of developing cerebral atherosclerosis in patients with OI. Therefore, patients with OI should give up smooking, exercise properly and keep on a low fat diet. They should pay attention to control blood pressure and blood lipid so as to reduce the risk of atherosclerosis. Conclusion: A c.3159 + 2T&gt;A mutation in COL1A2 gene detected by whole exome sequencing was the causing reason of OI, the discovery enriched the gene mutation spectrum of OI. We also found that OI may have relationship with premature atherosclerosis, and the abnormal bones of the cervical spine may lead to vertebrobasilar ischemia.


2018 ◽  
Author(s):  
Anthony M. Musolf ◽  
Haiming Sun ◽  
Bilal A. Moiz ◽  
Diptasri Mandal ◽  
Mariza de Andrade ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Yiehen Tung ◽  
Haiying Lu ◽  
Wenxin Lin ◽  
Tingting Huang ◽  
Samuel Kim ◽  
...  

Objective: 1q44 microdeletion syndrome is difficult to diagnose due to the wide phenotypic spectrum and strong genetic heterogeneity. We explore the correlation between the chromosome microdeletions and phenotype in a child with 1q44 microdeletion syndrome, we collected the clinical features of the patient and combined them with adjacent copy number variation (CNV) regions previously reported.Methods: We collected the full medical history of the patient and summarized her clinical symptoms. Whole-exome sequencing (WES) and CapCNV analysis were performed with DNA extracted from both the patient's and her parents' peripheral blood samples. Fluorescent quantitative PCR (q-PCR) was performed for the use of verification to the CNV regions.Results: A 28.7 KB microdeletion was detected in the 1q44 region by whole-exome sequencing and low-depth whole-genome sequencing. The deleted region included the genes COX20 and HNRNPU. As verification, karyotype analysis showed no abnormality, and the results of qPCR were consistent with that of whole-exome sequencing and CapCNV analysis.Conclusion: The patient was diagnosed with 1q44 microdeletion syndrome with clinical and genetic analysis. Analyzing both whole-exome sequencing and CapCNV analysis can not only improve the diagnostic rate of clinically suspected syndromes that present with intellectual disability (ID) and multiple malformations but also support further study of the correlation between CNVs and clinical phenotypes. This study lays the foundation for the further study of the pathogenesis of complex diseases.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 656-656
Author(s):  
Naoko Hosono ◽  
Hideki Makishima ◽  
Bartlomiej P Przychodzen ◽  
Andres Jerez ◽  
Chantana Polprasert ◽  
...  

Abstract Interstitial deletion of chromosome 5q (del(5q)) is one of the most common karyotypic abnormalities in MDS. While a relatively small fraction of patients with del(5q) and 5q- syndrome show a relatively uniform clinical phenotype and a low rate of progression, the majority of del(5q) myeloid neoplasms are more heterogeneous. Prognosis correlates with the size and location of the deletion, with large deletions spanning subtelomeric and/or subcentromeric region correlating with a poor prognosis. Survival differences may relate to still undefined pathogenetic mechanisms underlying del(5q), which may involve hemizygous mutations or haploinsufficiency. With the latter scenario, it is possible that heterozygous mutations of genes located on 5q may phenocopy the deletion. To further elucidate the molecular mechanisms underlying del(5q), we preformed a comprehensive analysis of myeloid neoplasms using single nucleotide polymorphism array (SNP-A) and next generation whole exome sequencing (NGS) of paired DNA samples (germline/tumor) from 55 cases characterized by del(5q) among a total 428 patients with MDS and related disorders; we focused on mutations located on 5q in both diploid and deletion cases. In the total cohort, we identified 243 somatic mutations in 158 genes on chr5q, including well-known NPM1 or novel recurrent DDX41 mutations; 147 mutations were heterozygous, 11 hemizygous (in del(5q)). No homozygous mutations were found. Applying SNP-A-based karyotyping, we defined the commonly deleted region (CDR) as between 5q32 and 5q33.2 (145299747-153828955). In patients with 5q- syndrome, the proximal and terminal regions of chr5q were always retained; therefore we defined commonly retained regions (CRR) as CRR1 (proximal, 5q11.1 to 5q14.2, 48400001-81634579) and CRR2 (distal, 5q34 to 5q35.3, 164213764-180915260). The deletions of CRRs consequently contributed to worse prognosis in the aggressive types of MDS with longer del(5q). First we focused our study on the genes located on CRRs. We identified 120 heterozygous alterations in CRRs, including CWC27 (5q12.3), MAP1B (n=2, 5q13.2), NPM (n=50, 5q35.1), C5orf25 (n=4, 5q35.2) and DDX41 (n=4, 5q35.3); these mutations occurred only in a heterozygous configuration. Interestingly, spliceosome-associated gene CWC27 and RNA helicase DDX41 showed haploinsufficient expression in haploid cases without mutation, suggesting that mutated genes located on CRRs can be pathogenic due to both haploinsufficiency of WT genes and heterozygous mutations. Furthermore, patients with decreased expression of these genes had a poor survival (CWC27; HR=2.48, DDX41; HR=1.98). In positions corresponding to CDR and its proximal regions, we found 123 heterozygous alterations in 97 genes (50% of all alterations on 5q found), including recurrently mutated genes (FAT2: n=4; G3BP1: n=2) and hemizygous mutations of KDM3B (n=3, 5q31.2) and MCC (n=1, 5q22.2). In GPR98, associated with Usher syndrome, we detected both recurrent heterozygous and hemizygous mutations (each n=1). Also, minor alleles (frequencies were .002 and .004) of non-synonymous variants of GPR98 were selectively retained and wild-type alleles were deleted in del(5q) cases (n=2). We also searched accessory genetic events observed on other chromosomes in del(5q) cases. By SNP-A, deletions of CRRs (longer del(5q)) were significantly more associated with additional chromosomal defects. Similarly, some specific genes, including the splicing machinery genes and IDH family genes, were uniquely observed in the longer del(5q) cohort. In conclusion, we detected multiple pathogenic mutations in whole chr5q which might stratify del(5q) patients at risk for disease progression, though no single mutations could explain a majority of cases. Decreased expression or mutation of CWC27 and DDX41, located on CRRs, may exemplify the common pathophysiology shared by heterozygous mutations and haploinsufficient expressions on chr5q. Consequently, it is possible that deletion alone, through decreased expression, may be pathogenic. Disclosures: Makishima: AA & MDS international foundation: Research Funding; Scott Hamilton CARES grant: Research Funding. Polprasert:MDS foundation: Research Funding. Maciejewski:NIH: Research Funding; Aplastic anemia&MDS International Foundation: Research Funding.


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