Whole-Exome Molecular Autopsy After Exertion-Related Sudden Unexplained Death in the Young.

Circ Cardiovasc Genet. 2016 Jun;9(3):259-65

Authors: Anderson JH, Tester DJ, Will ML, Ackerman MJ

Abstract
BACKGROUND: Targeted postmortem genetic testing of the 4 major channelopathy-susceptibility genes (KCNQ1, KCNH2, SCN5A, and RYR2) have yielded putative pathogenic mutations in ≤30% of autopsy-negative sudden unexplained death in the young (SUDY) cases with highest yields derived from the subset of exertion-related SUDY. Here, we evaluate the role of whole-exome sequencing in exertion-related SUDY cases.
METHODS AND RESULTS: From 1998 to 2010, 32 cases of exertion-related SUDY were referred by Medical Examiners for a cardiac channel molecular autopsy. A mutational analysis of the major long-QT syndrome-susceptibility genes (KCNQ1, KCNH2, and SCN5A) and catecholaminergic polymorphic ventricular tachycardia-susceptibility gene (RYR2) identified a putative pathogenic mutation in 11 cases. Whole-exome sequencing was performed on the remaining 21 targeted gene-negative SUDY cases. After whole-exome sequencing, a gene-specific surveillance of all genes (N=100) implicated in sudden death was performed to identify putative pathogenic mutation(s). Three of these 21 decedents had a clinically actionable, pathogenic mutation (CALM2-F90L, CALM2-N98S, and PKP2-N634fs). Of the 18 remaining cases, 7 hosted at least 1 variant of unknown significance with a minor allele frequency <1:20 000. The overall yield of pathogenic mutations was higher among decedents aged 1 to 10 years (10/11, 91%) than those aged 11 to 19 years (4/21, 19%, P=0.0001).
CONCLUSIONS: Molecular screening in this clinical scenario is appropriate with a pathogenic mutation detection rate of 44% using direct DNA sequencing followed by whole-exome sequencing. Only 5 of the 100 interrogated sudden death genes hosted actionable pathogenic mutations for more than one third of these exertion-related, autopsy-negative SUDY cases.

PMID: 27114410 [PubMed - indexed for MEDLINE]

HDL Cholesterol Metabolism and the Risk of CHD: New Insights from Human Genetics.

Curr Cardiol Rep. 2017 Nov 04;19(12):132

Authors: Vitali C, Khetarpal SA, Rader DJ

Abstract
PURPOSE OF REVIEW: Elevated high-density lipoprotein cholesterol levels in the blood (HDL-C) represent one of the strongest epidemiological surrogates for protection against coronary heart disease (CHD), but recent human genetic and pharmacological intervention studies have raised controversy about the causality of this relationship. Here, we review recent discoveries from human genome studies using new analytic tools as well as relevant animal studies that have both addressed, and in some cases, fueled this controversy.
RECENT FINDINGS: Methodologic developments in genotyping and sequencing, such as genome-wide association studies (GWAS), exome sequencing, and exome array genotyping, have been applied to the study of HDL-C and risk of CHD in large, multi-ethnic populations. Some of these efforts focused on population-wide variation in common variants have uncovered new polymorphisms at novel loci associated with HDL-C and, in some cases, CHD risk. Other efforts have discovered loss-of-function variants for the first time in genes previously implicated in HDL metabolism through common variant studies or animal models. These studies have allowed the genetic relationship between these pathways, HDL-C and CHD to be explored in humans for the first time through analysis tools such as Mendelian randomization. We explore these discoveries for selected key HDL-C genes CETP, LCAT, LIPG, SCARB1, and novel loci implicated from GWAS including GALNT2, KLF14, and TTC39B. Recent human genetics findings have identified new nodes regulating HDL metabolism while reshaping our current understanding of known candidate genes to HDL and CHD risk through the study of critical variants across model systems. Despite their effect on HDL-C, variants in many of the reviewed genes were found to lack any association with CHD. These data collectively indicate that HDL-C concentration, which represents a static picture of a very dynamic and heterogeneous metabolic milieu, is unlikely to be itself causally protective against CHD. In this context, human genetics represent an extremely valuable tool to further explore the biological mechanisms regulating HDL metabolism and investigate what role, if any, HDL plays in the pathogenesis of CHD.

PMID: 29103089 [PubMed - in process]

Intersociety policy statement on the use of whole-exome sequencing in the critically ill newborn infant.

Ital J Pediatr. 2017 Nov 03;43(1):100

Authors: Borghesi A, Mencarelli MA, Memo L, Ferrero GB, Bartuli A, Genuardi M, Stronati M, Villani A, Renieri A, Corsello G, their respective Scientific Societies

Abstract
The rapid advancement of next-generation sequencing (NGS) technology and the decrease in costs for whole-exome sequencing (WES) and whole-genome sequening (WGS), has prompted its clinical application in several fields of medicine. Currently, there are no specific guidelines for the use of NGS in the field of neonatal medicine and in the diagnosis of genetic diseases in critically ill newborn infants. As a consequence, NGS may be underused with reduced diagnostic success rate, or overused, with increased costs for the healthcare system. Most genetic diseases may be already expressed during the neonatal age, but their identification may be complicated by nonspecific presentation, especially in the setting of critical clinical conditions. The differential diagnosis process in the neonatal intensive care unit (NICU) may be time-consuming, uncomfortable for the patient due to repeated sampling, and ineffective in reaching a molecular diagnosis during NICU stay. Serial gene sequencing (Sanger sequencing) may be successful only for conditions for which the clinical phenotype strongly suggests a diagnostic hypothesis and for genetically homogeneous diseases. Newborn screenings with Guthrie cards, which vary from country to country, are designed to only test for a few dozen genetic diseases out of the more than 6000 diseases for which a genetic characterization is available. The use of WES in selected cases in the NICU may overcome these issues. We present an intersociety document that aims to define the best indications for the use of WES in different clinical scenarios in the NICU. We propose that WES is used in the NICU for critically ill newborn infants when an early diagnosis is desirable to guide the clinical management during NICU stay, when a strong hypothesis cannot be formulated based on the clinical phenotype or the disease is genetically heterogeneous, and when specific non-genetic laboratory tests are not available. The use of WES may reduce the time for diagnosis in infants during NICU stay and may eventually result in cost-effectiveness.

PMID: 29100554 [PubMed - in process]

11 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

(exome OR "exome sequencing") AND disease

These pubmed results were generated on 2017/11/04

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Diagnosis of lethal or prenatal-onset autosomal recessive disorders by parental exome sequencing.

Prenat Diagn. 2017 Nov 02;:

Authors: Stals KL, Wakeling M, Baptista J, Caswell R, Parrish A, Rankin J, Tysoe C, Jones G, Gunning AC, Lango-Allen H, Bradley L, Brady AF, Carley H, Carmichael J, Castle B, Cilliers D, Cox H, Deshpande C, Dixit A, Eason J, Elmslie F, Fry AE, Fryer A, Holder M, Homfray T, Kivuva E, McKay V, Newbury-Ecob R, Parker M, Savarirayan R, Searle C, Shannon N, Shears D, Smithson S, Thomas E, Turnpenny PD, Varghese V, Vasudevan P, Wakeling E, Baple EL, Ellard S

Abstract
OBJECTIVE: Rare genetic disorders resulting in prenatal or neonatal death are genetically heterogeneous but testing is often limited by the availability of fetal DNA, leaving couples without a potential prenatal test for future pregnancies. We describe our novel strategy of exome sequencing parental DNA samples to diagnose recessive monogenic disorders in an audit of the first 50 couples referred.
METHOD: Exome sequencing was carried out in a consecutive series of 50 couples who had one or more pregnancies affected with a lethal or prenatal-onset disorder. In all cases there was insufficient DNA for exome sequencing of the affected fetus. Heterozygous rare variants (MAF<0.001) in the same gene in both parents were selected for analysis. Likely disease-causing variants were tested in fetal DNA to confirm co-segregation.
RESULTS: Parental exome analysis identified heterozygous pathogenic (or likely pathogenic) variants in 24 different genes in 26/50 couples (52%). Where two or more fetuses were affected a genetic diagnosis was obtained in 18/29 cases (62%). In most cases the clinical features were typical of the disorder, but in others they result from a hypomorphic variant or represent the most severe form of a variable phenotypic spectrum.
CONCLUSION: We conclude that exome sequencing of parental samples is a powerful strategy with high clinical utility for the genetic diagnosis of lethal or prenatal-onset recessive disorders.

PMID: 29096039 [PubMed - as supplied by publisher]

Proband-only medical exome sequencing as a cost-effective first-tier genetic diagnostic test for patients without prior molecular tests and clinical diagnosis in a developing country: the China experience.

Genet Med. 2017 Nov 02;:

Authors: Hu X, Li N, Xu Y, Li G, Yu T, Yao RE, Fu L, Wang J, Yin L, Yin Y, Wang Y, Jin X, Wang X, Wang J, Shen Y

Abstract
PurposeTo evaluate the performance of proband-only medical exome sequencing (POMES) as a cost-effective first-tier diagnostic test for pediatric patients with unselected conditions.MethodsA total of 1,323 patients were tested by POMES, which targeted 2,742 known disease-causing genes. Clinical relevant variants were Sanger-confirmed in probands and parents. We assessed the diagnostic validity and clinical utility of POMES by means of a survey questionnaire.ResultsPOMES, ordered by 136 physicians, identified 512 pathogenic or likely pathogenic variants associated with over 200 conditions. The overall diagnostic rate was 28.8%, ranging from 10% in neonatal intensive care unit patients to over 35% in pediatric intensive care unit patients. The test results had an impact on the management of the 45.1% of patients for whom there were positive findings. The average turnaround time was 57 days; the cost was $360/case.ConclusionWe adopted a relatively efficient and cost-effective approach in China for the molecular diagnosis of pediatric patients with suspected genetic conditions. While training for clinical geneticists and other specialists is lagging behind in China POMES is serving as a diagnostic equalizer for patients who do not normally receive extensive clinical evaluation and clinical diagnosis prior to testing. This Chinese experience should be applicable to other developing countries that are lacking clinical, financial, and personnel resources.GENETICS in MEDICINE advance online publication, 2 November 2017; doi:10.1038/gim.2017.195.

PMID: 29095814 [PubMed - as supplied by publisher]

Genetics of vestibular syndromes.

Curr Opin Neurol. 2017 Nov 01;:

Authors: Roman-Naranjo P, Gallego-Martinez A, Lopez Escamez JA

Abstract
PURPOSE OF REVIEW: The increased availability of next generation sequencing has enabled a rapid progress in the discovery of genetic variants associated with vestibular disorders. We have summarized molecular genetics finding in vestibular syndromes during the last 18 months.
RECENT FINDINGS: Genetic studies continue to shed light on the genetic background of vestibular disorders. Novel genes affecting brain development and otolith biogenesis have been associated with motion sickness. Exome sequencing has made possible to identify three rare single nucleotide variants in PRKCB, DPT and SEMA3D linked with familial Meniere disease. Moreover, superior canal dehiscence syndrome might be related with variants in CDH3 gene, by increasing risk of its development. On the other hand, the association between vestibular schwannoma and enlarged vestibular aqueduct with variants in NF2 and SLC26A4, respectively, seems increasingly clear. Finally, the use of mouse models is allowing further progress in the development gene therapy for hearing and vestibular monogenic disorders.
SUMMARY: Most of episodic or progressive syndromes show familial clustering. A detailed phenotyping with a complete familial history of vestibular symptoms is required to conduct a genetic study. Progress in these studies will allow us to understand diseases mechanisms and improve their current medical treatments.

PMID: 29095749 [PubMed - as supplied by publisher]

Sporadic Hirschsprung Disease: Mutational Spectrum and Novel Candidate Genes Revealed by Next-generation Sequencing.

Sci Rep. 2017 Nov 01;7(1):14796

Authors: Zhang Z, Li Q, Diao M, Liu N, Cheng W, Xiao P, Zou J, Su L, Yu K, Wu J, Li L, Jiang Q

Abstract
Hirschsprung disease (HSCR) is a common cause of functional colonic obstruction in children. The currently available genetic testing is often inadequate as it mainly focuses on RET and several other genes, accounting for only 15-20% of cases. To identify novel, potentially pathogenic variants, we isolated a panel of genes from a whole-exome sequencing study and from the published mouse aganglionosis phenotypes, enteric nervous system development, and a literature review. The coding exons of 172 genes were analyzed in 83 sporadic patients using next-generation sequencing. Rare stop-gain, splice-site variants, frameshift and in-frame insertions/deletions and non-synonymous variants (conserved and predicted to be deleterious) were prioritized as the most promising variants to have an effect on HSCR and subjected to burden analysis. GeneMANIA interaction database was used to identify protein-protein interaction-based networks. In addition, 6 genes (PTPN13, PHKB, AGL, ZFHX3, LAMA1, and AP3B2) were prioritized for follow-up studies: both their time-space expression patterns in mouse and human colon showed that they are good candidates for predicting pathogenicity. The results of this study broaden the mutational spectrum of HSCR candidate genes, and they provide an insight into the relative contributions of individual genes to this highly heterogeneous disorder.

PMID: 29093530 [PubMed - in process]

WISP3 mutation associated with Pseudorheumatoid Dysplasia.

Cold Spring Harb Mol Case Stud. 2017 Nov 01;:

Authors: Sailani MR, Chappell J, Inlora J, Lynch L, Narasimha A, Mazroui S, Zia A, Bernstein J, Aryani O, Snyder MP

Abstract
Progressive pseudorheumatoid dysplasia (PPD) is a skeletal dysplasia characterized by predominant involvement of articular cartilage with progressive joint stiffness. Here we report genetic characterization of a consanguineous family segregating an uncharacterized from of skeletal dysplasia. Whole exome sequencing of four affected siblings and their parents identified a loss of function homozygous mutation in the WISP3 gene, leading to diagnosis of PPD in the affected individuals. The identified variant (chr6: 112382301; WISP3:c.156C>A p.Cys52*) is rare and predicted to cause premature termination of the WISP3 protein.

PMID: 29092958 [PubMed - as supplied by publisher]

Biallelic Mutations in KDSR Disrupt Ceramide Synthesis and Result in a Spectrum of Keratinization Disorders Associated with Thrombocytopenia.

J Invest Dermatol. 2017 Nov;137(11):2344-2353

Authors: Takeichi T, Torrelo A, Lee JYW, Ohno Y, Lozano ML, Kihara A, Liu L, Yasuda Y, Ishikawa J, Murase T, Rodrigo AB, Fernández-Crehuet P, Toi Y, Mellerio J, Rivera J, Vicente V, Kelsell DP, Nishimura Y, Okuno Y, Kojima D, Ogawa Y, Sugiura K, Simpson MA, McLean WHI, Akiyama M, McGrath JA

Abstract
Mutations in ceramide biosynthesis pathways have been implicated in a few Mendelian disorders of keratinization, although ceramides are known to have key roles in several biological processes in skin and other tissues. Using whole-exome sequencing in four probands with undiagnosed skin hyperkeratosis/ichthyosis, we identified compound heterozygosity for mutations in KDSR, encoding an enzyme in the de novo synthesis pathway of ceramides. Two individuals had hyperkeratosis confined to palms, soles, and anogenital skin, whereas the other two had more severe, generalized harlequin ichthyosis-like skin. Thrombocytopenia was present in all patients. The mutations in KDSR were associated with reduced ceramide levels in skin and impaired platelet function. KDSR enzymatic activity was variably reduced in all patients, resulting in defective acylceramide synthesis. Mutations in KDSR have recently been reported in inherited recessive forms of progressive symmetric erythrokeratoderma, but our study shows that biallelic mutations in KDSR are implicated in an extended spectrum of disorders of keratinization in which thrombocytopenia is also part of the phenotype. Mutations in KDSR cause defective ceramide biosynthesis, underscoring the importance of ceramide and sphingosine synthesis pathways in skin and platelet biology.

PMID: 28774589 [PubMed - indexed for MEDLINE]

NOX1 loss-of-function genetic variants in patients with inflammatory bowel disease.

Mucosal Immunol. 2017 Nov 01;:

Authors: Schwerd T, Bryant RV, Pandey S, Capitani M, Meran L, Cazier JB, Jung J, Mondal K, Parkes M, Mathew CG, Fiedler K, McCarthy DJ, WGS500 Consortium, Oxford IBD cohort study investigators, COLORS in IBD group investigators, UK IBD Genetics Consortium, Sullivan PB, Rodrigues A, Travis SPL, Moore C, Sambrook J, Ouwehand WH, Roberts DJ, Danesh J, INTERVAL Study, Russell RK, Wilson DC, Kelsen JR, Cornall R, Denson LA, Kugathasan S, Knaus UG, Serra EG, Anderson CA, Duerr RH, McGovern DP, Cho J, Powrie F, Li VS, Muise AM, Uhlig HH

Abstract
Genetic defects that affect intestinal epithelial barrier function can present with very early-onset inflammatory bowel disease (VEOIBD). Using whole-genome sequencing, a novel hemizygous defect in NOX1 encoding NAPDH oxidase 1 was identified in a patient with ulcerative colitis-like VEOIBD. Exome screening of 1,878 pediatric patients identified further seven male inflammatory bowel disease (IBD) patients with rare NOX1 mutations. Loss-of-function was validated in p.N122H and p.T497A, and to a lesser degree in p.Y470H, p.R287Q, p.I67M, p.Q293R as well as the previously described p.P330S, and the common NOX1 SNP p.D360N (rs34688635) variant. The missense mutation p.N122H abrogated reactive oxygen species (ROS) production in cell lines, ex vivo colonic explants, and patient-derived colonic organoid cultures. Within colonic crypts, NOX1 constitutively generates a high level of ROS in the crypt lumen. Analysis of 9,513 controls and 11,140 IBD patients of non-Jewish European ancestry did not reveal an association between p.D360N and IBD. Our data suggest that loss-of-function variants in NOX1 do not cause a Mendelian disorder of high penetrance but are a context-specific modifier. Our results implicate that variants in NOX1 change brush border ROS within colonic crypts at the interface between the epithelium and luminal microbes.Mucosal Immunology advance online publication 1 November 2017. doi:10.1038/mi.2017.74.

PMID: 29091079 [PubMed - as supplied by publisher]

Whole exome sequencing in 342 congenital cardiac left sided lesion cases reveals extensive genetic heterogeneity and complex inheritance patterns.

Genome Med. 2017 Oct 31;9(1):95

Authors: Li AH, Hanchard NA, Furthner D, Fernbach S, Azamian M, Nicosia A, Rosenfeld J, Muzny D, D'Alessandro LCA, Morris S, Jhangiani S, Parekh DR, Franklin WJ, Lewin M, Towbin JA, Penny DJ, Fraser CD, Martin JF, Eng C, Lupski JR, Gibbs RA, Boerwinkle E, Belmont JW

Abstract
BACKGROUND: Left-sided lesions (LSLs) account for an important fraction of severe congenital cardiovascular malformations (CVMs). The genetic contributions to LSLs are complex, and the mutations that cause these malformations span several diverse biological signaling pathways: TGFB, NOTCH, SHH, and more. Here, we use whole exome sequence data generated in 342 LSL cases to identify likely damaging variants in putative candidate CVM genes.
METHODS: Using a series of bioinformatics filters, we focused on genes harboring population-rare, putative loss-of-function (LOF), and predicted damaging variants in 1760 CVM candidate genes constructed a priori from the literature and model organism databases. Gene variants that were not observed in a comparably sequenced control dataset of 5492 samples without severe CVM were then subjected to targeted validation in cases and parents. Whole exome sequencing data from 4593 individuals referred for clinical sequencing were used to bolster evidence for the role of candidate genes in CVMs and LSLs.
RESULTS: Our analyses revealed 28 candidate variants in 27 genes, including 17 genes not previously associated with a human CVM disorder, and revealed diverse patterns of inheritance among LOF carriers, including 9 confirmed de novo variants in both novel and newly described human CVM candidate genes (ACVR1, JARID2, NR2F2, PLRG1, SMURF1) as well as established syndromic CVM genes (KMT2D, NF1, TBX20, ZEB2). We also identified two genes (DNAH5, OFD1) with evidence of recessive and hemizygous inheritance patterns, respectively. Within our clinical cohort, we also observed heterozygous LOF variants in JARID2 and SMAD1 in individuals with cardiac phenotypes, and collectively, carriers of LOF variants in our candidate genes had a four times higher odds of having CVM (odds ratio = 4.0, 95% confidence interval 2.5-6.5).
CONCLUSIONS: Our analytical strategy highlights the utility of bioinformatic resources, including human disease records and model organism phenotyping, in novel gene discovery for rare human disease. The results underscore the extensive genetic heterogeneity underlying non-syndromic LSLs, and posit potential novel candidate genes and complex modes of inheritance in this important group of birth defects.

PMID: 29089047 [PubMed - in process]

Whole-exome sequencing reveals genetic variants in ERC1 and KCNG4 associated with complete hydatidiform mole in Chinese Han women.

Oncotarget. 2017 Sep 26;8(43):75264-75271

Authors: Yu Y, Lu B, Lu W, Li S, Li X, Wang X, Wan X, Chen Y, Feng S, Jia Y, Yang R, Tang F, Li X, Zhang S, Wang X, Wei H, Peng Z, Lu L, Zhong H, Zhao L, Huang Z, Lin L, Shen W, Lu Y, Cao Z, Zou J, Ma Y, Chen X, Tian Q, Lu S, Liu P, Ma D, Xie X, Cheng X

Abstract
Complete hydatidiform mole (CHM) is a rare pregnancy-related disease with invasive potential. The genetics underlying the sporadic form of CHM have not been addressed previously, but maternal genetic variants may be involved in biparental CHM. We performed whole-exome sequencing of 51 patients with CHM and 47 healthy women to identify genetic variants associated with CHM. In addition, candidate variants were analyzed using single base extension and Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry in 199 CHM patients and 400 healthy controls. We validated candidate variants using Sanger sequencing in 250 cases and 652 controls, including 205 new controls. Two single nucleotide polymorphisms, c.G48C(p.Q16H) inERC1 and c.G1114A(p.G372S) in KCNG4, were associated with an increased risk of CHM (p<0.05). These variants may contribute to the pathogenesis of CHM and could be used to screen pregnant women for this genetic abnormality.

PMID: 29088863 [PubMed]

Patient-specific molecular alterations are associated with metastatic clear cell renal cell cancer progressing under tyrosine kinase inhibitor therapy.

Oncotarget. 2017 Sep 26;8(43):74049-74057

Authors: Dietz S, Sültmann H, Du Y, Reisinger E, Riediger AL, Volckmar AL, Stenzinger A, Schlesner M, Jäger D, Hohenfellner M, Duensing S, Grüllich C, Pahernik S

Abstract
The availability of tyrosine kinase inhibitors (TKI) during the past ten years has led to improved response and overall survival of patients suffering from metastatic clear cell renal cell carcinoma (ccRCC). However, most of these tumors will eventually progress due to resistance evolving under therapy. The objective of this pilot study was to determine whether molecular alterations in ccRCC tissues sampled over the course of the disease might be suggestive of potential therapies. We performed whole exome sequencing of nine samples from four patients in the MORE (Molecular Renal Cancer Evolution) trial. We analyzed the mutational patterns in the tissues at baseline and compared them to those detectable in biopsy samples after progression under TKI therapy. We found limited genetic concordance between primary and secondary tumor sites with private mutations in FLT4, MTOR, ITGA5, SETD2, PBRM1, and BRCA1 on progression. One patient who showed an increased mutational load in the metastasis responded to nivolumab treatment. Our data provide evidence for clonal evolution and diverse pathways leading to acquired TKI resistance of ccRCC. Acquired resistance to TKI in metastatic ccRCC is due to intra-tumor heterogeneity and clonal evolution of resistant subclones. Mutations occurring under progression might be informative for alternative targeted therapies.

PMID: 29088767 [PubMed]

GNE missense mutation in recessive familial amyotrophic lateral sclerosis.

Neurogenetics. 2017 Oct 31;:

Authors: Köroğlu Ç, Yılmaz R, Sorgun MH, Solakoğlu S, Şener Ö

Abstract
Amyotrophic lateral sclerosis (ALS) is a motor neuron disease eventually leading to death from respiratory failure. Recessive inheritance is very rare. Here, we describe the clinical findings in a consanguineous family with five men afflicted with recessive ALS and the identification of the homozygous mutation responsible for the disorder. The onset of the disease ranged from 12 to 35 years of age, with variable disease progressions. We performed clinical investigations including metabolic and paraneoplastic screening, cranial and cervical imaging, and electrophysiology. We mapped the disease gene to 9p21.1-p12 with a LOD score of 5.2 via linkage mapping using genotype data for single-nucleotide polymorphism markers and performed exome sequence analysis to identify the disease-causing gene variant. We also Sanger sequenced all coding sequences of SIGMAR1, a gene reported as responsible for juvenile ALS in a family. We did not find any mutation in SIGMAR1. Instead, we identified a novel homozygous missense mutation p.(His705Arg) in GNE which was predicted as damaging by online tools. GNE has been associated with inclusion body myopathy and is expressed in many tissues. We propose that the GNE mutation underlies the pathology in the family.

PMID: 29086072 [PubMed - as supplied by publisher]

Characterizing temporal genomic heterogeneity in pediatric high-grade gliomas.

Acta Neuropathol Commun. 2017 Oct 30;5(1):78

Authors: Salloum R, McConechy MK, Mikael LG, Fuller C, Drissi R, DeWire M, Nikbakht H, De Jay N, Yang X, Boue D, Chow LML, Finlay JL, Gayden T, Karamchandani J, Hummel TR, Olshefski R, Osorio DS, Stevenson C, Kleinman CL, Majewski J, Fouladi M, Jabado N

Abstract
Pediatric high-grade gliomas (pHGGs) are aggressive neoplasms representing approximately 20% of brain tumors in children. Current therapies offer limited disease control, and patients have a poor prognosis. Empiric use of targeted therapy, especially at progression, is increasingly practiced despite a paucity of data regarding temporal and therapy-driven genomic evolution in pHGGs. To study the genetic landscape of pHGGs at recurrence, we performed whole exome and methylation analyses on matched primary and recurrent pHGGs from 16 patients. Tumor mutational profiles identified three distinct subgroups. Group 1 (n = 7) harbored known hotspot mutations in Histone 3 (H3) (K27M or G34V) or IDH1 (H3/IDH1 mutants) and co-occurring TP53 or ACVR1 mutations in tumor pairs across the disease course. Group 2 (n = 7), H3/IDH1 wildtype tumor pairs, harbored novel mutations in chromatin modifiers (ZMYND11, EP300 n = 2), all associated with TP53 alterations, or had BRAF V600E mutations (n = 2) conserved across tumor pairs. Group 3 included 2 tumors with NF1 germline mutations. Pairs from primary and relapsed pHGG samples clustered within the same DNA methylation subgroup. ATRX mutations were clonal and retained in H3G34V and H3/IDH1 wildtype tumors, while different genetic alterations in this gene were observed at diagnosis and recurrence in IDH1 mutant tumors. Mutations in putative drug targets (EGFR, ERBB2, PDGFRA, PI3K) were not always shared between primary and recurrence samples, indicating evolution during progression. Our findings indicate that specific key driver mutations in pHGGs are conserved at recurrence and are prime targets for therapeutic development and clinical trials (e.g. H3 post-translational modifications, IDH1, BRAF V600E). Other actionable mutations are acquired or lost, indicating that re-biopsy at recurrence will provide better guidance for effective targeted therapy of pHGGs.

PMID: 29084603 [PubMed - in process]

Mutations in CEP120 cause Joubert syndrome as well as complex ciliopathy phenotypes.

J Med Genet. 2016 Sep;53(9):608-15

Authors: Roosing S, Romani M, Isrie M, Rosti RO, Micalizzi A, Musaev D, Mazza T, Al-Gazali L, Altunoglu U, Boltshauser E, D'Arrigo S, De Keersmaecker B, Kayserili H, Brandenberger S, Kraoua I, Mark PR, McKanna T, Van Keirsbilck J, Moerman P, Poretti A, Puri R, Van Esch H, Gleeson JG, Valente EM

Abstract
BACKGROUND: Ciliopathies are an extensive group of autosomal recessive or X-linked disorders with considerable genetic and clinical overlap, which collectively share multiple organ involvement and may result in lethal or viable phenotypes. In large numbers of cases the genetic defect remains yet to be determined. The aim of this study is to describe the mutational frequency and phenotypic spectrum of the CEP120 gene.
METHODS: Exome sequencing was performed in 145 patients with Joubert syndrome (JS), including 15 children with oral-facial-digital syndrome type VI (OFDVI) and 21 Meckel syndrome (MKS) fetuses. Moreover, exome sequencing was performed in one fetus with tectocerebellar dysraphia with occipital encephalocele (TCDOE), molar tooth sign and additional skeletal abnormalities. As a parallel study, 346 probands with a phenotype consistent with JS or related ciliopathies underwent next-generation sequencing-based targeted sequencing of 120 previously described and candidate ciliopathy genes.
RESULTS: We present six probands carrying nine distinct mutations (of which eight are novel) in the CEP120 gene, previously found mutated only in Jeune asphyxiating thoracic dystrophy (JATD). The CEP120-associated phenotype ranges from mild classical JS in four patients to more severe conditions in two fetuses, with overlapping features of distinct ciliopathies that include TCDOE, MKS, JATD and OFD syndromes. No obvious correlation is evident between the type or location of identified mutations and the ciliopathy phenotype.
CONCLUSION: Our findings broaden the spectrum of phenotypes caused by CEP120 mutations that account for nearly 1% of patients with JS as well as for more complex ciliopathy phenotypes. The lack of clear genotype-phenotype correlation highlights the relevance of comprehensive genetic analyses in the diagnostics of ciliopathies.

PMID: 27208211 [PubMed - indexed for MEDLINE]

11 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

(exome OR "exome sequencing") AND disease

These pubmed results were generated on 2017/10/31

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

11 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

(exome OR "exome sequencing") AND disease

These pubmed results were generated on 2017/10/31

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Next generation sequencing in pediatric hepatology and liver transplantation.

Liver Transpl. 2017 Oct 28;:

Authors: Nicastro E, D'Antiga L

Abstract
Next Generation Sequencing (NGS) has revolutionized the analysis of human genetic variations, offering a highly cost-effective way to diagnose monogenic diseases (MDs). Since nearly half of children with chronic liver disorders have a genetic cause and approximately 20% of pediatric liver transplants are performed in children with MDs, NGS offers the opportunity to significantly improve the diagnostic yield in this field. Among the NGS strategies, the use of targeted gene panels has proven useful to rapidly and reliably confirm a clinical suspicion, whereas the whole exome sequencing (WES) with variants filtering has been adopted to assist the diagnostic work up in unclear clinical scenarios. WES is powerful but challenging, since it detects a great number of variants of unknown significance, that can be misinterpreted and lead to an incorrect diagnosis. In pediatric hepatology targeted NGS can be very valuable to discriminate neonatal/infantile cholestatic disorders, disclose genetic causes of acute liver failure, diagnose the subtype of inborn errors of metabolism presenting with a similar phenotype (such as glycogen storage disorders, mitochondrial cytopathies or non-alcoholic fatty liver disease). The inclusion of NGS in diagnostic processes will lead to a paradigm shift in medicine, changing our approach to the patient as well as our understanding of factors affecting genotype-phenotype match. In this review we discuss the opportunities and the challenges offered nowadays by NGS, and we propose a novel algorithm for cholestasis of infancy adopted in our center, including targeted NGS as a pivotal tool for the diagnosis of liver based MDs. This article is protected by copyright. All rights reserved.

PMID: 29080241 [PubMed - as supplied by publisher]