Germline mutations in candidate predisposition genes in individuals with cutaneous melanoma and at least two independent additional primary cancers.

PLoS One. 2018;13(4):e0194098

Authors: Pritchard AL, Johansson PA, Nathan V, Howlie M, Symmons J, Palmer JM, Hayward NK

Abstract
BACKGROUND: While a number of autosomal dominant and autosomal recessive cancer syndromes have an associated spectrum of cancers, the prevalence and variety of cancer predisposition mutations in patients with multiple primary cancers have not been extensively investigated. An understanding of the variants predisposing to more than one cancer type could improve patient care, including screening and genetic counselling, as well as advancing the understanding of tumour development.
METHODS: A cohort of 57 patients ascertained due to their cutaneous melanoma (CM) diagnosis and with a history of two or more additional non-cutaneous independent primary cancer types were recruited for this study. Patient blood samples were assessed by whole exome or whole genome sequencing. We focussed on variants in 525 pre-selected genes, including 65 autosomal dominant and 31 autosomal recessive cancer predisposition genes, 116 genes involved in the DNA repair pathway, and 313 commonly somatically mutated in cancer. The same genes were analysed in exome sequence data from 1358 control individuals collected as part of non-cancer studies (UK10K). The identified variants were classified for pathogenicity using online databases, literature and in silico prediction tools.
RESULTS: No known pathogenic autosomal dominant or previously described compound heterozygous mutations in autosomal recessive genes were observed in the multiple cancer cohort. Variants typically found somatically in haematological malignancies (in JAK1, JAK2, SF3B1, SRSF2, TET2 and TYK2) were present in lymphocyte DNA of patients with multiple primary cancers, all of whom had a history of haematological malignancy and cutaneous melanoma, as well as colorectal cancer and/or prostate cancer. Other potentially pathogenic variants were discovered in BUB1B, POLE2, ROS1 and DNMT3A. Compared to controls, multiple cancer cases had significantly more likely damaging mutations (nonsense, frameshift ins/del) in tumour suppressor and tyrosine kinase genes and higher overall burden of mutations in all cancer genes.
CONCLUSIONS: We identified several pathogenic variants that likely predispose to at least one of the tumours in patients with multiple cancers. We additionally present evidence that there may be a higher burden of variants of unknown significance in 'cancer genes' in patients with multiple cancer types. Further screens of this nature need to be carried out to build evidence to show if the cancers observed in these patients form part of a cancer spectrum associated with single germline variants in these genes, whether multiple layers of susceptibility exist (oligogenic or polygenic), or if the occurrence of multiple different cancers is due to random chance.

PMID: 29641532 [PubMed - indexed for MEDLINE]

Genetic Influences on Evening Preference Overlap with Those for Bipolar Disorder in a Sample of Mexican Americans and American Indians.

Twin Res Hum Genet. 2017 Dec;20(6):499-510

Authors: Melroy-Greif WE, Gizer IR, Wilhelmsen KC, Ehlers CL

Abstract
Diurnal preference (e.g., being an owl or lark) has been associated with several psychiatric disorders including bipolar disorder (BP), major depressive disorder, and substance use disorders. Previous large-scale genome-wide association studies (GWAS) aimed at identifying genetic influences on diurnal preference have exclusively included subjects of European ancestry. This study examined the genetic architecture of diurnal preference in two minority samples: a young adult sample of Mexican Americans (MAs), and a family-based sample of American Indians (AIs). Typed or imputed variants from exome chip data from the MA sample and low pass whole-genome sequencing from the AI cohort were analyzed using a mixed linear model approach for association with being an owl, as defined by a usual bedtime after 23:00 hrs. Genetic risk score (GRS) profiling detected shared genetic risk between evening preference and related disorders. Four variants in KIAA1549 like (KIAA1549L), a gene previously associated with attempted suicide in bipolar patients, were suggestively associated with being an owl at p < 1.82E-05; post hoc analyses showed the top variant trending in both the MA and AI cohorts at p = 2.50E-05 and p = .030, respectively. Variants associated with BP at p < .03 from the Psychiatric Genomics Consortium nominally predicted being an owl in the MA/AI cohort at p = .012. This study provides some additional evidence that genetic risk factors for BP also confer risk for being an owl in MAs/AIs and that evening preference may be a useful endophenotype for future studies of BP.

PMID: 29192581 [PubMed - indexed for MEDLINE]

The Second Case of Saposin A Deficiency and Altered Autophagy.

JIMD Rep. 2018 Jul 12;:

Authors: Kose M, Demir SA, Akinci G, Eraslan C, Yilmaz U, Ceylaner S, Yildirim ES, Seyrantepe V

Abstract
Krabbe disease is a lysosomal storage disease caused by galactosylceramidase deficiency, resulting in neurodegeneration with a rapid clinical downhill course within the first months of life in the classic infantile form. This process may be triggered by the accumulation of galactosylceramide (GalCer) in nervous tissues. Both the enzyme galactosylceramidase and its in vivo activator molecule, saposin A, are essential during GalCer degradation. A clinical manifestation almost identical to Krabbe disease is observed when, instead of the galactosylceramidase protein, the saposin A molecule is defective. Saposin A results from posttranslational processing of the precursor molecule, prosaposin, encoded by the PSAP gene. Clinical and neuroimaging findings in a 7-month-old child strongly suggested Krabbe disease, but this condition was excluded by enzymatic and genetic testing. However, at whole exome sequencing, the previously undescribed homozygous, obviously pathogenic PSAP gene NM_002778.3:c.209T>G(p.Val70Gly) variant was determined in the saposin A domain of the PSAP gene. Fibroblast studies showed GalCer accumulation and the activation of autophagy for the first time in a case of human saposin A deficiency. Our patient represents the second known case in the literature and provides new information concerning the pathophysiology of saposin A deficiency and its intralysosomal effects.

PMID: 29995202 [PubMed - as supplied by publisher]

Loss-of-function mutations of SCN10A encoding NaV1.8 α subunit of voltage-gated sodium channel in patients with human kidney stone disease.

Sci Rep. 2018 Jul 11;8(1):10453

Authors: Nettuwakul C, Praditsap O, Sawasdee N, Rungroj N, Ruamyod K, Watanapa WB, Junking M, Sangnual S, Sritippayawan S, Cheunsuchon B, Chuawattana D, Rojsatapong S, Chaowagul W, Dib-Hajj SD, Waxman SG, Yenchitsomanus PT

Abstract
Human kidney stone disease (KSD) causes significant morbidity and public health burden worldwide. The etiology of KSD is heterogeneous, ranging from monogenic defects to complex interaction between genetic and environmental factors. However, the genetic defects causing KSD in the majority of affected families are still unknown. Here, we report the discovery of mutations of SCN10A, encoding NaV1.8 α subunit of voltage-gated sodium channel, in families with KSD. The region on chromosome 3 where SCN10A locates was initially identified in a large family with KSD by genome-wide linkage analysis and exome sequencing. Two mutations (p.N909K and p.K1809R) in the same allele of SCN10A co-segregated with KSD in the affected family. Additional mutation (p.V1149M) of SCN10A was identified in another affected family, strongly supporting the causal role of SCN10A for KSD. The amino acids at these three positions, N909, K1809, and V1149, are highly conserved in vertebrate evolution, indicating their structural and functional significances. NaV1.8 α subunit mRNA and protein were found to express in human kidney tissues. The mutant proteins expressed in cultured cells were unstable and causing reduced current density as analyzed by whole-cell patch-clamp technique. Thus, loss-of-function mutations of SCN10A were associated with KSD in the families studied.

PMID: 29992996 [PubMed - in process]

Somatic mutations in specific and connected sub-pathways are associated to short neuroblastoma patients' survival and indicate proteins targetable at onset of disease.

Int J Cancer. 2018 Jul 11;:

Authors: Esposito MR, Binatti A, Pantile M, Coppe A, Mazzocco K, Longo L, Capasso M, Lasorsa VA, Luksch R, Bortoluzzi S, Tonini GP

Abstract
Neuroblastoma (NB) is an embryonic malignancy of the sympathetic nervous system with heterogeneous biological, morphological, genetic and clinical characteristics. Although genomic studies revealed the specific biological features of NB pathogenesis useful for new therapeutic approaches, the improvement of high-risk (HR)-NB patients overall survival is still unsatisfactory. To further clarify the biological basis of disease aggressiveness, we used whole exome sequencing to examine the genomic landscape of HR-NB patients at stage M with short survival (SS) and long survival (LS). Only a few genes, including SMARCA4, SMO, ZNF44 and CHD2, were recurrently and specifically mutated in the SS group, confirming the low recurrence of common mutations in this tumor. A systems biology approach revealed that in the two patient groups, mutations occurred in different pathways. Mutated genes (ARHGEF11, CACNA1G, FGF4, PTPRA, PTK2, ANK3, SMO, NTNG2, VCL and NID2) regulate the MAPK pathway associated with the organization of the extracellular matrix, cell motility through PTK2 signaling and matrix metalloproteinase activity. Moreover, we detected mutations in LAMA2, PTK2, LAMA4, and MMP14 genes, impairing MET signaling, in SFI1 and CHD2 involved in centrosome maturation and chromosome remodeling, in AK7 and SPTLC2, which regulate the metabolism of nucleotides and lipoproteins, and in NALCN, SLC12A1, SLC9A9, which are involved in the transport of small molecules. Notably, connected networks of somatically mutated genes specific for SS patients were identified. The detection of mutated genes present at the onset of disease may help to address an early treatment of HR-NB patients using FDA-approved compounds targeting the deregulated pathways. This article is protected by copyright. All rights reserved.

PMID: 29992558 [PubMed - as supplied by publisher]

Epilepsy Genetics: current knowledge, applications and future directions.

Clin Genet. 2018 Jul 10;:

Authors: Myers KA, Johnstone D, Dyment DA

Abstract
The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate NGS-based test(s) and the interpretation of sequencing results require a care-provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will likely also include other -omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease. This article is protected by copyright. All rights reserved.

PMID: 29992546 [PubMed - as supplied by publisher]

Integrative DNA copy number detection and genotyping from sequencing and array-based platforms.

Bioinformatics. 2018 Jul 15;34(14):2349-2355

Authors: Zhou Z, Wang W, Wang LS, Zhang NR

Abstract
Motivation: Copy number variations (CNVs) are gains and losses of DNA segments and have been associated with disease. Many large-scale genetic association studies are performing CNV analysis using whole exome sequencing (WES) and whole genome sequencing (WGS). In many of these studies, previous single-nucleotide polymorphism (SNP)-array data are available. An integrated cross-platform analysis is expected to improve resolution and accuracy, yet there is no tool for effectively combining data from sequencing and array platforms. The detection of CNVs using sequencing data alone can also be further improved by the utilization of allele-specific reads.
Results: We propose a statistical framework, integrated CNV (iCNV) detection algorithm, which can be applied to multiple study designs: WES only, WGS only, SNP array only, or any combination of SNP and sequencing data. iCNV applies platform-specific normalization, utilizes allele specific reads from sequencing and integrates matched NGS and SNP-array data by a hidden Markov model. We compare integrated two-platform CNV detection using iCNV to naïve intersection or union of platforms and show that iCNV increases sensitivity and robustness. We also assess the accuracy of iCNV on WGS data only and show that the utilization of allele-specific reads improve CNV detection accuracy compared to existing methods.
Availability and implementation: https://github.com/zhouzilu/iCNV.
Supplementary information: Supplementary data are available at Bioinformatics online.

PMID: 29992253 [PubMed - in process]

Evolutionary history of human colitis-associated colorectal cancer.

Gut. 2018 Jul 10;:

Authors: Baker AM, Cross W, Curtius K, Al Bakir I, Choi CR, Davis HL, Temko D, Biswas S, Martinez P, Williams MJ, Lindsay JO, Feakins R, Vega R, Hayes SJ, Tomlinson IPM, McDonald SAC, Moorghen M, Silver A, East JE, Wright NA, Wang LM, Rodriguez-Justo M, Jansen M, Hart AL, Leedham SJ, Graham TA

Abstract
OBJECTIVE: IBD confers an increased lifetime risk of developing colorectal cancer (CRC), and colitis-associated CRC (CA-CRC) is molecularly distinct from sporadic CRC (S-CRC). Here we have dissected the evolutionary history of CA-CRC using multiregion sequencing.
DESIGN: Exome sequencing was performed on fresh-frozen multiple regions of carcinoma, adjacent non-cancerous mucosa and blood from 12 patients with CA-CRC (n=55 exomes), and key variants were validated with orthogonal methods. Genome-wide copy number profiling was performed using single nucleotide polymorphism arrays and low-pass whole genome sequencing on archival non-dysplastic mucosa (n=9), low-grade dysplasia (LGD; n=30), high-grade dysplasia (HGD; n=13), mixed LGD/HGD (n=7) and CA-CRC (n=19). Phylogenetic trees were reconstructed, and evolutionary analysis used to reveal the temporal sequence of events leading to CA-CRC.
RESULTS: 10/12 tumours were microsatellite stable with a median mutation burden of 3.0 single nucleotide alterations (SNA) per Mb, ~20% higher than S-CRC (2.5 SNAs/Mb), and consistent with elevated ageing-associated mutational processes. Non-dysplastic mucosa had considerable mutation burden (median 47 SNAs), including mutations shared with the neighbouring CA-CRC, indicating a precancer mutational field. CA-CRCs were often near triploid (40%) or near tetraploid (20%) and phylogenetic analysis revealed that copy number alterations (CNAs) began to accrue in non-dysplastic bowel, but the LGD/HGD transition often involved a punctuated 'catastrophic' CNA increase.
CONCLUSIONS: Evolutionary genomic analysis revealed precancer clones bearing extensive SNAs and CNAs, with progression to cancer involving a dramatic accrual of CNAs at HGD. Detection of the cancerised field is an encouraging prospect for surveillance, but punctuated evolution may limit the window for early detection.

PMID: 29991641 [PubMed - as supplied by publisher]

Expanding Phenotype of Nephronophthisis-Related Ciliopathy: an Elderly Patient with Homozygous RPGRIP1L Mutation.

Nephron. 2018 Jul 10;:1-5

Authors: Kawaguchi T, Yoshida T, Hirahashi J, Uehara T, Takenouchi T, Kosaki K, Itoh H, Hayashi M

Abstract
Nephronophthisis-related ciliopathies (NPHP-RC) are autosomal recessive disorders characterized by renal corticomedullary cysts with the extrarenal symptoms. Typically, patients with NPHP-RC reach end-stage kidney disease (ESKD) before the age of 30 years. We herein report a Japanese woman with NPHP-RC who had unusually delayed progression to ESKD after 6 decades. She exhibited liver dysfunction at the age of 23 years. She also showed mild renal dysfunction at the age of 43 years. Ultrasonography revealed bilateral multiple renal cysts with loss of corticomedullary differentiation. Her liver and renal functions gradually deteriorated. She was diagnosed with liver fibrosis as a result of biopsy, and initiated the maintenance hemodiafiltration therapy for ESKD at the age of 61 years. Because of a unique combination of multiple renal cysts and liver fibrosis, ciliopathy was suspected and medical exome analysis was performed. A novel homozygous missense mutation was identified in RPGRIP1L (c.1810G>A p.Glu604Lys), a causative gene for NPHP-RC. To the best of our knowledge, this patient is the oldest one who progressed to ESKD in NPHP-RC. Our case illustrates that NPHP-RC should be included in the differential diagnosis of the patient with corticomedullary polycystic kidneys accompanied by the extrarenal organ involvements, even if the patient is elderly.

PMID: 29991045 [PubMed - as supplied by publisher]

A novel SLC1A4 homozygous mutation causing congenital microcephaly, epileptic encephalopathy and spastic tetraparesis: a video-EEG and tractography - case study.

J Neurogenet. 2018 Jul 10;:1-6

Authors: Pironti E, Salpietro V, Cucinotta F, Granata F, Mormina E, Efthymiou S, Scuderi C, Gagliano A, Houlden H, Di Rosa G

Abstract
Biallelic mutations in the SLC1A4 gene have been identified as a very rare cause of neurodevelopmental disorders. l-serine transport deficiency has been regarded as the causal molecular mechanism underlying the neurological phenotype of SLC1A4 mutation patients. To date this genetic condition has been reported almost exclusively in a limited number of Ashkenazi-Jewish individuals and as a result the SLC1A4 gene is not routinely included in the majority of the genetic diagnostic panels for neurological diseases. We hereby report a 7-year-old boy from a Southern Italian family, presenting with epileptic encephalopathy, congenital microcephaly, global developmental delay, severe hypotonia, spasticity predominant at the lower limbs, and thin corpus callosum. Whole exome sequencing identified a novel segregating SLC1A4 gene homozygous mutation (c.1141G > A: p.Gly381Arg) as the likely cause of the disease in our family. In order to deeply characterize the electro-clinical and neurological phenotype in our index patient, long-term systematic video-electroencephalograms (EEG) as well as repeated brain imaging studies (which included tractographic reconstructions) were performed on a regular basis during a 7 years follow-up time. In conclusion, we suggest to carefully considering SLC1A4 biallelic mutations in individuals presenting an early onset severe neurodevelopmental disorder with variable spasticity and seizures, regardless the patients' ethnic background.

PMID: 29989513 [PubMed - as supplied by publisher]

New generation sequencing of targeted genes in the classical and the variant form of hairy cell leukemia highlights mutations in epigenetic regulation genes.

Oncotarget. 2018 Jun 22;9(48):28866-28876

Authors: Maitre E, Bertrand P, Maingonnat C, Viailly PJ, Wiber M, Naguib D, Salaün V, Cornet E, Damaj G, Sola B, Jardin F, Troussard X

Abstract
Classical hairy cell leukemia (HCL-c) is a rare lymphoid neoplasm. BRAFV600E mutation, detected in more than 80% of the cases, is described as a driver mutation, but additional genetic abnormalities appear to be necessary for the disease progression. For cases of HCL-c harboring a wild-type BRAF gene, the differential diagnosis of the variant form of HCL (HCL-v) or splenic diffuse red pulp lymphoma (SDRPL) is complex. We selected a panel of 21 relevant genes based on a literature review of whole exome sequencing studies (BRAF, MAP2K1, DUSP2, MAPK15, ARID1A, ARID1B, EZH2, KDM6A, CREBBP, TP53, CDKN1B, XPO1, KLF2, CXCR4, NOTH1, NOTCH2, MYD88, ANXA1, U2AF1, BCOR, and ABCA8). We analyzed 20 HCL-c and 4 HCL-v patients. The analysis of diagnostic samples mutations in BRAF (n = 18), KLF2 (n = 4), MAP2K1 (n = 3), KDM6A (n = 2), CDKN1B (n = 2), ARID1A (n = 2), CREBBP (n = 2) NOTCH1 (n = 1) and ARID1B (n = 1). BRAFV600E was found in 90% (18/20) of HCL-c patients. In HCL-c patients with BRAFV600E , other mutations were found in 33% (6/18) of cases. All 4 HCL-v patients had mutations in epigenetic regulatory genes: KDM6A (n = 2), CREBBP (n = 1) or ARID1A (n = 1). The analysis of sequential samples (at diagnosis and relapse) from 5 patients (2 HCL-c and 3 HCL-v), showed the presence of 2 new subclonal mutations (BCORE1430X and XPO1E571K ) in one patient and variations of the mutated allele frequency in 2 other cases. In the HCL-v disease, we described new mutations targeting KDM6A that encode a lysine demethylase protein. This opens new perspectives for personalized medicine for this group of patients.

PMID: 29989027 [PubMed]

An Exome-wide Association Study for Type 2 Diabetes-Attributed End-Stage Kidney Disease in African Americans.

Kidney Int Rep. 2018 Jul;3(4):867-878

Authors: Guan M, Keaton JM, Dimitrov L, Hicks PJ, Xu J, Palmer ND, Wilson JG, Freedman BI, Bowden DW, Ng MCY

Abstract
Introduction: Compared with European Americans, African Americans (AAs) are at higher risk for developing end-stage kidney disease (ESKD). Genome-wide association studies (GWAS) have identified >70 genetic variants associated with kidney function and chronic kidney disease (CKD) in patients with and without diabetes. However, these variants explain a small proportion of disease liability. This study examined the contribution of coding genetic variants for risk of type 2 diabetes (T2D)-attributed ESKD and advanced CKD in AAs.
Methods: Exome sequencing was performed in 456 AA T2D-ESKD cases, and 936 AA nondiabetic, non-nephropathy control individuals at the discovery stage. A mixed logistic regression model was used for association analysis. Nominal associations (P < 0.05) were replicated in an additional 2020 T2D-ESKD cases and 1121 nondiabetic, non-nephropathy control individuals. A meta-analysis combining 4533 discovery and replication samples was performed. Putative T2D-ESKD associations were tested in additional 1910 nondiabetic ESKD and 219 T2D-ESKD cases, as well as 912 AA nondiabetic non-nephropathy control individuals.
Results: A total of 11 suggestive T2D-ESKD associations (P < 1 x 10-4) from 8 loci (PLEKHN1, NADK, RAD51AP2, RREB1, PEX6, GRM8, PRX, APOL1) were apparent in the meta-analysis. Exclusion of APOL1 renal-risk genotype carriers identified 3 additional suggestive loci (OTUD7B, IFITM3, DLGAP5). Rs41302867 in RREB1 displayed consistent association with T2D-ESKD and nondiabetic ESKD (odds ratio: 0.47; P = 1.2 x 10-6 in 4605 all-cause ESKD and 2969 nondiabetic non-nephropathy control individuals).
Conclusion: Our findings suggest that coding genetic variants are implicated in predisposition to T2D-ESKD in AAs.

PMID: 29989002 [PubMed]

Novel ETFDH mutations in four cases of riboflavin responsive multiple acyl-CoA dehydrogenase deficiency.

Mol Genet Metab Rep. 2018 Sep;16:15-19

Authors: Fan X, Xie B, Zou J, Luo J, Qin Z, D'Gama AM, Shi J, Yi S, Yang Q, Wang J, Luo S, Chen S, Agrawal PB, Li Q, Shen Y

Abstract
Multiple acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive disorder of fatty acid, amino acid, and choline metabolism caused by mutations in EFTA, EFTB, or ETFDH. Many MADD patients are responsive to treatment with riboflavin, termed riboflavin-responsive MADD (RR-MADD). Here, we report three novel mutations and one previously reported mutation in ETFDH in four RR-MADD patients who presented at various ages, and characterize the corresponding changes in ETF-QO protein structure. Clinicians should consider MADD in the differential diagnosis when patients present with muscle weakness and biochemical abnormalities. Gene testing plays a critical role in confirming the diagnosis of MADD, and may not only prevent patients from invasive testing, but also allow timely initiation of riboflavin treatment. The novel variants in ETFDH and the corresponding clinical features reported here enrich the allelic heterogeneity of RR-MADD and provide insight into genotype-phenotype relationships.

PMID: 29988809 [PubMed]

A rare loss-of-function variant of ADAM17 is associated with late-onset familial Alzheimer disease.

Mol Psychiatry. 2018 Jul 09;:

Authors: Hartl D, May P, Gu W, Mayhaus M, Pichler S, Spaniol C, Glaab E, Bobbili DR, Antony P, Koegelsberger S, Kurz A, Grimmer T, Morgan K, Vardarajan BN, Reitz C, Hardy J, Bras J, Guerreiro R, Balling R, Schneider JG, Riemenschneider M, AESG

Abstract
Common variants of about 20 genes contributing to AD risk have so far been identified through genome-wide association studies (GWAS). However, there is still a large proportion of heritability that might be explained by rare but functionally important variants. One of the so far identified genes with rare AD causing variants is ADAM10. Using whole-genome sequencing we now identified a single rare nonsynonymous variant (SNV) rs142946965 [p.R215I] in ADAM17 co-segregating with an autosomal-dominant pattern of late-onset AD in one family. Subsequent genotyping and analysis of available whole-exome sequencing data of additional case/control samples from Germany, UK, and USA identified five variant carriers among AD patients only. The mutation inhibits pro-protein cleavage and the formation of the active enzyme, thus leading to loss-of-function of ADAM17 alpha-secretase. Further, we identified a strong negative correlation between ADAM17 and APP gene expression in human brain and present in vitro evidence that ADAM17 negatively controls the expression of APP. As a consequence, p.R215I mutation of ADAM17 leads to elevated Aß formation in vitro. Together our data supports a causative association of the identified ADAM17 variant in the pathogenesis of AD.

PMID: 29988083 [PubMed - as supplied by publisher]

Clonal Hematopoiesis: Somatic Mutations in Blood Cells and Atherosclerosis.

Circ Genom Precis Med. 2018 Jul;11(7):e001926

Authors: Natarajan P, Jaiswal S, Kathiresan S

Abstract
The most important prognostic factor for atherosclerotic cardiovascular disease is age, independent of all other recognized risk factors. Recently, exome sequence analyses showed that somatic mutations in blood cells, a process termed clonal hematopoiesis, are common and increase in prevalence with age, with at least 1 in 10 adults older than 70 years affected. Carriers of clonal hematopoiesis have been shown to be not only at heightened risk for hematologic malignancy but also at increased risk for atherosclerotic cardiovascular disease. Here, we review the prior literature of clonal selection and expansion of hematopoietic stem cells and the evidence supporting its causal association with atherosclerotic cardiovascular disease.

PMID: 29987111 [PubMed - in process]

Comprehensive genomic diagnosis of non-syndromic and syndromic hereditary hearing loss in Spanish patients.

BMC Med Genomics. 2018 Jul 09;11(1):58

Authors: Cabanillas R, Diñeiro M, Cifuentes GA, Castillo D, Pruneda PC, Álvarez R, Sánchez-Durán N, Capín R, Plasencia A, Viejo-Díaz M, García-González N, Hernando I, Llorente JL, Repáraz-Andrade A, Torreira-Banzas C, Rosell J, Govea N, Gómez-Martínez JR, Núñez-Batalla F, Garrote JA, Mazón-Gutiérrez Á, Costales M, Isidoro-García M, García-Berrocal B, Ordóñez GR, Cadiñanos J

Abstract
BACKGROUND: Sensorineural hearing loss (SNHL) is the most common sensory impairment. Comprehensive next-generation sequencing (NGS) has become the standard for the etiological diagnosis of early-onset SNHL. However, accurate selection of target genomic regions (gene panel/exome/genome), analytical performance and variant interpretation remain relevant difficulties for its clinical implementation.
METHODS: We developed a novel NGS panel with 199 genes associated with non-syndromic and/or syndromic SNHL. We evaluated the analytical sensitivity and specificity of the panel on 1624 known single nucleotide variants (SNVs) and indels on a mixture of genomic DNA from 10 previously characterized lymphoblastoid cell lines, and analyzed 50 Spanish patients with presumed hereditary SNHL not caused by GJB2/GJB6, OTOF nor MT-RNR1 mutations.
RESULTS: The analytical sensitivity of the test to detect SNVs and indels on the DNA mixture from the cell lines was > 99.5%, with a specificity > 99.9%. The diagnostic yield on the SNHL patients was 42% (21/50): 47.6% (10/21) with autosomal recessive inheritance pattern (BSND, CDH23, MYO15A, STRC [n = 2], USH2A [n = 3], RDX, SLC26A4); 38.1% (8/21) autosomal dominant (ACTG1 [n = 3; 2 de novo], CHD7, GATA3 [de novo], MITF, P2RX2, SOX10), and 14.3% (3/21) X-linked (COL4A5 [de novo], POU3F4, PRPS1). 46.9% of causative variants (15/32) were not in the databases. 28.6% of genetically diagnosed cases (6/21) had previously undetected syndromes (Barakat, Usher type 2A [n = 3] and Waardenburg [n = 2]). 19% of genetic diagnoses (4/21) were attributable to large deletions/duplications (STRC deletion [n = 2]; partial CDH23 duplication; RDX exon 2 deletion).
CONCLUSIONS: In the era of precision medicine, obtaining an etiologic diagnosis of SNHL is imperative. Here, we contribute to show that, with the right methodology, NGS can be transferred to the clinical practice, boosting the yield of SNHL genetic diagnosis to 50-60% (including GJB2/GJB6 alterations), improving diagnostic/prognostic accuracy, refining genetic and reproductive counseling and revealing clinically relevant undiagnosed syndromes.

PMID: 29986705 [PubMed - in process]

The BabySeq project: implementing genomic sequencing in newborns.

BMC Pediatr. 2018 Jul 09;18(1):225

Authors: Holm IA, Agrawal PB, Ceyhan-Birsoy O, Christensen KD, Fayer S, Frankel LA, Genetti CA, Krier JB, LaMay RC, Levy HL, McGuire AL, Parad RB, Park PJ, Pereira S, Rehm HL, Schwartz TS, Waisbren SE, Yu TW, BabySeq Project Team, Green RC, Beggs AH

Abstract
BACKGROUND: The greatest opportunity for lifelong impact of genomic sequencing is during the newborn period. The "BabySeq Project" is a randomized trial that explores the medical, behavioral, and economic impacts of integrating genomic sequencing into the care of healthy and sick newborns.
METHODS: Families of newborns are enrolled from Boston Children's Hospital and Brigham and Women's Hospital nurseries, and half are randomized to receive genomic sequencing and a report that includes monogenic disease variants, recessive carrier variants for childhood onset or actionable disorders, and pharmacogenomic variants. All families participate in a disclosure session, which includes the return of results for those in the sequencing arm. Outcomes are collected through review of medical records and surveys of parents and health care providers and include the rationale for choice of genes and variants to report; what genomic data adds to the medical management of sick and healthy babies; and the medical, behavioral, and economic impacts of integrating genomic sequencing into the care of healthy and sick newborns.
DISCUSSION: The BabySeq Project will provide empirical data about the risks, benefits and costs of newborn genomic sequencing and will inform policy decisions related to universal genomic screening of newborns.
TRIAL REGISTRATION: The study is registered in ClinicalTrials.gov Identifier: NCT02422511 . Registration date: 10 April 2015.

PMID: 29986673 [PubMed - in process]

Multi-modality analysis supports APOBEC as a major source of mutations in head and neck squamous cell carcinoma.

Oral Oncol. 2017 Nov;74:8-14

Authors: Faden DL, Thomas S, Cantalupo PG, Agrawal N, Myers J, DeRisi J

Abstract
OBJECTIVES: The mutagenic processes underlying head and neck squamous cell carcinoma (HNSCC) are poorly understood. Pan-cancer mutational signature analyses have identified a signature for APOBEC, a cytosine deaminase, in a subset of cancers, including HNSCC. The role of APOBEC activity in HNSCC remains poorly understood. Therefore, we sought to determine the role of APOBEC in HNSCC pathogenesis.
MATERIAL AND METHODS: Utilizing bioinformatic approaches we explored the role of APOBEC mediated mutations in tumor exomes, transcriptomes and germline exomes from 511HNSCC patients in the TCGA.
RESULTS: 58% of HNSCC were statistically enriched for the APOBEC signature. APOBEC3A expression had the highest correlation coefficient with APOBEC mutation rate. Gene specific motif analysis revealed a slight predominance of APOBEC3A mutations. Canonical pathway analysis demonstrated immune pathway upregulation in APOBEC mutation rich samples. Overall mutational burden was positively correlated with APOBEC enrichment.
CONCLUSIONS: APOBEC mediated mutations are highly prevalent in HNSCC. APOBEC3A is the most likely gene to be active in HPV+ HNSCC. APOBEC activity correlates with upregulation of immune signaling pathways, supporting the hypothesis that APOBEC activity could be activated as part of the innate immune response.

PMID: 29103756 [PubMed - indexed for MEDLINE]

[Significance of whole exome sequencing in the diagnostics of rare neurological diseases - own experiences through a case presenting with ataxia].

Orv Hetil. 2018 Jul;159(28):1163-1169

Authors: Balicza P, Grosz Z, Bencsik R, Illés A, Gál A, Gézsi A, Molnár MJ

Abstract
Next generation sequencing (NGS) technologies reshape the diagnostics of rare neurological diseases. In the background of certain neurological symptoms, such as ataxia, many acquired and genetic causes may be present. Variations in a given gene can present with variable phenotypes, too. Because of this phenomenon, the conventional one gene sequencing approach often fails to identify the genetic background of a disease. Next generation sequencing panels allow to sequence 50-100 genes simultaneously, and if the disease stratification is not possible based on the clinical symptoms, whole exome sequencing can help in the diagnostic of genetic disorders with atypical presentation. This case study is about the exome sequencing of a patient with cerebellar ataxia. Genetic investigations identified rare variants in the SPG11 gene in association with the clinical phenotype, which gene was originally described in the background of hereditary spastic paraparesis. Our article highlights that in certain cases the variability of the leading presenting symptom makes it hard to select the correct gene panel. In our case the variants in the gene, formerly associated to hereditary spastic paraparesis, resulted in cerebellar ataxia initially, so even an ataxia NGS gene panel would not detect those. Orv Hetil. 2018; 159(28): 1163-1169.

PMID: 29983107 [PubMed - in process]

Whole-Exome Sequencing Identifies Novel Recurrent Somatic Mutations in Sporadic Parathyroid Adenomas.

Endocrinology. 2018 Jul 03;:

Authors: Wei Z, Sun B, Wang ZP, He JW, Fu WZ, Fan YB, Zhang ZL

Abstract
Primary hyperparathyroidism is commonly casused by excess production of parathyroid hormone from sporadic parathyroid adenomas. However, the genetic architecture of sporadic primary hyperparathyroidism remains largely uncharacterized, especially in the Chinese population. To identify novel genetic abnormalities that may be involved in the etiology of sporadic parathyroid adenomas and to determine the mutation frequency of previously identified genes in the Chinese population, we performed whole-exome sequencing of 22 blood-tumor pairs from sporadic parathyroid adenomas. The most important finding is the recurrently mutated gene, ASXL3, which has never been reported in parathyroid tumors before. Moreover, we identified two different somatic mutations in the CDC73 gene and one somatic mutation in the EZH2 gene. The Y54X mutation in the CDC73 gene was previously identified in parathyroid carcinomas, which proved that parathyroid adenomas and carcinomas might possess similar molecular signatures. No mutations in the MEN1 or CCND1 genes were observed in our study. Thus, our data provide new insights into the genetic pathogenesis of sporadic parathyroid adenomas and are valuable for the development of diagnostic and therapeutic approaches for sporadic primary hyperparathyroidism.

PMID: 29982334 [PubMed - as supplied by publisher]