Exome Sequencing in Gastrointestinal Food Allergy Induced by Multiple Food Protein

[ES] Durante las últimas décadas, se han realizado importantes avances en el estudio de las causas genéticas de enfermedades raras y comunes, donde un gran número de variantes han sido identificadas y asociadas a múltiples enfermedades. Con las tecnologías de secuenciación de nueva generación, hoy en día somos capaces de investigar, con un alto rendimiento, la contribución de variantes de alta y baja frecuencia a distintos tipos de enfermedades, permitiéndonos así estudiar su importancia en el desarrollo de las mismas. En ésta tesis se ha utilizado la secuenciación del exoma como tecnología para el estudio de variantes raras en una enfermedad compleja, la alergia gastrointestinal inducida por múltiples alimentos. Para ello, se realizó la secuenciación del exoma completo de una cohorte de 31 individuos (ocho afectados y 23 no afectados) provenientes de siete familias diferentes. Se desarrolló un flujo de trabajo para procesar los datos generados a partir de diferentes librerías e instrumentos de secuenciación, así como un control de calidad exhaustivo con el fin de maximizar el número de variantes de alta calidad. Diferentes tipos de mutaciones fueron investigadas, incluyendo polimorfismos de nucleótido único, inserciones/deleciones, variantes del número de copia y haplotipos HLA, y se realizaron diferentes métodos de filtrado para su interpretación. Finalmente, se encontraron una serie de mutaciones que podrían estar asociadas con la enfermedad y se describe su posible papel en la patogénesis de las alergias gastrointestinales. Los resultados de esta tesis suponen importantes avances en el estudio de la compleja arquitectura genética de las alergias gastrointestinales y abren las puertas a futuras líneas de investigación, que serán necesarias para entender completamente las bases genéticas de esta enfermedad.[CA] Durant les últimes dècades, s'han realitzat importants avanços en l'estudi de les causes genètiques de malalties rares i comunes, on un gran nombre de variants han sigut identificades i associades a múltiples malalties. Amb les tecnologies de seqüenciació de nova generació, avui en dia som capaços d'investigar, amb un alt rendiment, la contribució de variants d'alta i baixa freqüència a diferents tipus de malalties, permetent-nos així estudiar la seva importància en el desenvolupament de les mateixes. En aquesta tesis s'ha utilitzat la seqüenciació del exoma com a tecnologia per a l'estudi de variants rares en una malaltia complexa, l'al·lèrgia gastrointestinal induïda per múltiples aliments. Per això, es va realitzar la seqüenciació del exoma complet d'una cohort de 31 individus (vuit afectats i 23 no afectats) provinents de set famílies diferents. Es va desenvolupar un flux de treball per a processar les dades generades a partir de diferents llibreries e instruments de seqüenciació, així com un control de qualitat exhaustiu amb la fi de maximitzar el nombre de variants d'alta qualitat. Diferents tipus de mutacions foren investigades, incloïent polimorfismes de nucleòtid únic, insercions/delecions, variants del nombre de còpia i haplotips HLA, i es realitzaren diferent mètodes de filtrat per a la seva interpretació. Finalment, es trobaren una sèrie de mutacions que podrien estar associades amb la malaltia i es descriu el seu possible paper en la patogènesis de les al·lèrgies gastrointestinals. Els resultats d'aquesta tesis suposen importants avanços en l'estudi de la complexa arquitectura genètica de les al·lèrgies gastrointestinals i obrin les portes a futures línies d'investigació, que seran necessàries per entendre completament les bases genètiques d'aquesta malaltia.[EN] The study of genetics has been making significant progress towards understanding the causes of rare and common disease during the past decades. Across a wide range of disorders, there have been hundreds of associated loci identified and associated with multiple disorders. Now, with the advent of next-generation sequencing technologies, we are able to interrogate the contribution of high and low frequency variation to disease in a high throughput manner. This provides an opportunity to investigate the role of rare variation in complex disease risk, potentially offering insights into disease pathogenesis and biological mechanisms. In this thesis, it has been assessed the use of whole-exome sequencing technology to investigate the role of rare variation in a complex disease, gastrointestinal food allergy induced by multiple food proteins. For that, a cohort of 31 individuals (eight affected and 23 non-affected) from seven different families was whole exome sequenced. Data obtained from multiple sequencing systems and libraries were analysed, and a workflow was developed, focusing on a comprehensive quality control to maximise the number of real positive calls. Different types of genome variations were investigated, including single nucleotide variants, insertions/deletions, copy number variants and HLA haplotypes. By approaching different methods of variant filtering, a set of rare variants that could be associated with the disease was identified. The possible role of these candidate variants in the pathogenesis of gastrointestinal food allergies was also discussed. These results reveal important insights into the genetic architecture of gastrointestinal food allergies and lead to additional lines of investigation that will be required in order to fully understand the genetic basis of this disease.Sanchis Juan, A. (2019). Exome Sequencing in Gastrointestinal Food Allergy Induced by Multiple Food Protein [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/134361TESI

Mapping the Constrained Coding Regions in the human genome to their corresponding proteins

Constrained Coding Regions (CCRs) in the human genome have been derived from DNA sequencing data of large cohorts of healthy control populations, available in the Genome Aggregation Database (gnomAD) [1]. They identify regions depleted of protein-changing variants and thus identify segments of the genome that have been constrained during human evolution. By mapping these DNA-defined regions from genomic coordinates onto the corresponding protein positions and combining this information with protein annotations, we have explored the distribution of CCRs and compared their co-occurrence with different protein functional features, previously annotated at the amino acid level in public databases. As expected, our results reveal that functional amino acids involved in interactions with DNA/RNA, protein-protein contacts and catalytic sites are the protein features most likely to be highly constrained for variation in the control population. More surprisingly, we also found that linear motifs, linear interacting peptides (LIPs), disorder-order transitions upon binding with other protein partners and liquid-liquid phase separating (LLPS) regions are also strongly associated with high constraint for variability. We also compared intra-species constraints in the human CCRs with inter-species conservation and functional residues to explore how such CCRs may contribute to the analysis of protein variants. As has been previously observed, CCRs are only weakly correlated with conservation, suggesting that intraspecies constraints complement interspecies conservation and can provide more information to interpret variant effects

Rare Genetic Variation in 135 Families With Family History Suggestive of X-Linked Intellectual Disability.

Families with multiple male children with intellectual disability (ID) are usually suspected of having disease due to a X-linked mode of inheritance and genetic studies focus on analysis of segregating variants in X-linked genes. However, the genetic cause of ID remains elusive in approximately 50% of affected individuals. Here, we report the analysis of next-generation sequencing data in 274 affected individuals from 135 families with a family history suggestive of X-linked ID. Genetic diagnoses were obtained for 19% (25/135) of the families, and 24% (33/135) had a variant of uncertain significance. In 12% of cases (16/135), the variants were not shared within the family, suggesting genetic heterogeneity and phenocopies are frequent. Of all the families with reportable variants (43%, 58/135), we observed that 55% (32/58) were in X-linked genes, but 38% (22/58) were in autosomal genes, while the remaining 7% (4/58) had multiple variants in genes with different modes on inheritance. This study highlights that in families with multiple affected males, X linkage should not be assumed, and both individuals should be considered, as different genetic etiologies are common in apparent familial cases

Realistic simulation of metal nanoparticles on solar cells

[EN] We present a strategy for simulating the scattering effect of an array of self-aggregated (SA) metal nanoparticles (NPs) on the light absorption in solar cells. We include size and shape effects of the NPs, the effect of a layered substrate and the effect of the interaction between NPs. The simulation relies on realistic characterization by SEM microscopy of the random NP arrays. Time and memory limitations of numerical approaches are overcome using semianalytical expressions. Size and shape considerations deal with truncated-sphere shapes by using a polarisability tensor. This is a development of other models leading to equivalent dipoles from the external source and the radiated fields from the rest of NPs. Once an equivalent array of 3-D dipoles is found, the total electromagnetic field and optical simulations are performed. The general trends show good agreement with experimental measurements. A critical analysis of the model is presented, and some improvement strategies are discussed for future studies.The authors would like to thank the R&D fellowship FPI-UPV (P.A.I.D. program of the Universitat Politècnica de València) and the EU-COST project “MultiscaleSolar” (MP1406) and Dr. Stéphane Collin from the Laboratory of Photonics and Nanostructures (CNRS-LPN) for helpful discussions and SEM characterisation.Cortés Juan, F.; Espinosa Soria, A.; Connolly, JP.; Sánchez Plaza, G.; Hugonin, J.; Sanchis Kilders, P. (2015). Realistic simulation of metal nanoparticles on solar cells. Energy Procedia. 84:204-213. doi:10.1016/j.egypro.2015.12.315S2042138

Abundancy of polymorphic CGG repeats in the human genome suggest a broad involvement in neurological disease.

Funder: Marguerite-Marie Delacroix foundationFunder: Fonds Wetenschappelijk Onderzoek - Vlaanderen (FWO)Funder: NIHR BioResourceFunder: Rosetrees Trust, Newton Trust, National Institute for Health Research (NIHR) for the Cambridge Biomedical Research CentreFunder: Methusalem-OEC grant – “GENOMED”Expanded CGG-repeats have been linked to neurodevelopmental and neurodegenerative disorders, including the fragile X syndrome and fragile X-associated tremor/ataxia syndrome (FXTAS). We hypothesized that as of yet uncharacterised CGG-repeat expansions within the genome contribute to human disease. To catalogue the CGG-repeats, 544 human whole genomes were analyzed. In total, 6101 unique CGG-repeats were detected of which more than 93% were highly variable in repeat length. Repeats with a median size of 12 repeat units or more were always polymorphic but shorter repeats were often polymorphic, suggesting a potential intergenerational instability of the CGG region even for repeats units with a median length of four or less. 410 of the CGG repeats were associated with known neurodevelopmental disease genes or with strong candidate genes. Based on their frequency and genomic location, CGG repeats may thus be a currently overlooked cause of human disease

Nuclear-mitochondrial DNA segments resemble paternally inherited mitochondrial DNA in humans.

Several strands of evidence question the dogma that human mitochondrial DNA (mtDNA) is inherited exclusively down the maternal line, most recently in three families where several individuals harbored a 'heteroplasmic haplotype' consistent with biparental transmission. Here we report a similar genetic signature in 7 of 11,035 trios, with allelic fractions of 5-25%, implying biparental inheritance of mtDNA in 0.06% of offspring. However, analysing the nuclear whole genome sequence, we observe likely large rare or unique nuclear-mitochondrial DNA segments (mega-NUMTs) transmitted from the father in all 7 families. Independently detecting mega-NUMTs in 0.13% of fathers, we see autosomal transmission of the haplotype. Finally, we show the haplotype allele fraction can be explained by complex concatenated mtDNA-derived sequences rearranged within the nuclear genome. We conclude that rare cryptic mega-NUMTs can resemble paternally mtDNA heteroplasmy, but find no evidence of paternal transmission of mtDNA in humans

Molecular dissection of structural variations involved in antithrombin deficiency

Inherited antithrombin deficiency, the most severe form of thrombophilia, is predominantly caused by variants in SERPINC1. Few causal structural variants have been described, usually detected by multiplex ligation-dependent probe amplification or cytogenetic arrays, which only define the gain or loss and the approximate size and location. This study has done a complete dissection of the structural variants affecting SERPINC1 of 39 unrelated patients with antithrombin deficiency using multiplex ligation-dependent probe amplification, comparative genome hybridization array, long-range PCR, and whole genome nanopore sequencing. Structural variants, in all cases only affecting one allele, were deleterious and caused a severe type I deficiency. Most defects were deletions affecting exons of SERPINC1 (82.1%), but the whole cohort was heterogeneous, as tandem duplications, deletion of introns, or retrotransposon insertions were also detected. Their size was also variable, ranging from 193 bp to 8 Mb, and in 54% of the cases involved neighboring genes. All but two structural variants had repetitive elements and/or microhomologies in their breakpoints, suggesting a common mechanism of formation. This study also suggested regions recurrently involved in structural variants causing antithrombin deficiency and found three structural variants with a founder effect: the insertion of a retrotransposon, duplication of exon 6, and a 20-gene deletion. Finally, nanopore sequencing was determined to be the most appropriate method to identify and characterize all structural variants at nucleotide level, independently of their size or type.Supported by the National Institute for Health Research (NIHR) for the NIHR BioResource project (grant numbers RG65966 and RG94028), by the Instituto de Salud Carlos III grant; Fondo Europeo de Desarrollo Regional (FEDER) grant PI18/00598; and Fundación Séneca 19873/GERM/15. M.E.d.l.M.-B. has a postdoctoral contract from University of Murcia, Murcia, Spain. C.B.-P. has a Río Hortega fellowship. B.d.l.M.-B. has a postdoctoral fellowship from Fundación Séneca. J.C.-G. has a predoctoral fellowship from the Ministry of Universities FPU19/03662

Whole genome sequencing reveals that genetic conditions are frequent in intensively ill children.

PURPOSE: With growing evidence that rare single gene disorders present in the neonatal period, there is a need for rapid, systematic, and comprehensive genomic diagnoses in ICUs to assist acute and long-term clinical decisions. This study aimed to identify genetic conditions in neonatal (NICU) and paediatric (PICU) intensive care populations. METHODS: We performed trio whole genome sequence (WGS) analysis on a prospective cohort of families recruited in NICU and PICU at a single site in the UK. We developed a research pipeline in collaboration with the National Health Service to deliver validated pertinent pathogenic findings within 2-3 weeks of recruitment. RESULTS: A total of 195 families had whole genome analysis performed (567 samples) and 21% received a molecular diagnosis for the underlying genetic condition in the child. The phenotypic description of the child was a poor predictor of the gene identified in 90% of cases, arguing for gene agnostic testing in NICU/PICU. The diagnosis affected clinical management in more than 65% of cases (83% in neonates) including modification of treatments and care pathways and/or informing palliative care decisions. A 2-3 week turnaround was sufficient to impact most clinical decision-making. CONCLUSIONS: The use of WGS in intensively ill children is acceptable and trio analysis facilitates diagnoses. A gene agnostic approach was effective in identifying an underlying genetic condition, with phenotypes and symptomatology being primarily used for data interpretation rather than gene selection. WGS analysis has the potential to be a first-line diagnostic tool for a subset of intensively ill children

Rare Variants Found in Clinical Gene Panels Illuminate the Genetic and Allelic Architecture of Orofacial Clefting

PURPOSE: Orofacial clefts (OFCs) are common birth defects including cleft lip, cleft lip and palate, and cleft palate. OFCs have heterogeneous etiologies, complicating clinical diagnostics because it is not always apparent if the cause is Mendelian, environmental, or multifactorial. Sequencing is not currently performed for isolated or sporadic OFCs; therefore, we estimated the diagnostic yield for 418 genes in 841 cases and 294 controls. METHODS: We evaluated 418 genes using genome sequencing and curated variants to assess their pathogenicity using American College of Medical Genetics criteria. RESULTS: 9.04% of cases and 1.02% of controls had likely pathogenic variants (P \u3c .0001), which was almost exclusively driven by heterozygous variants in autosomal genes. Cleft palate (17.6%) and cleft lip and palate (9.09%) cases had the highest yield, whereas cleft lip cases had a 2.80% yield. Out of 39 genes with likely pathogenic variants, 9 genes, including CTNND1 and IRF6, accounted for more than half of the yield (4.64% of cases). Most variants (61.8%) were variants of uncertain significance , occurring more frequently in cases (P = .004), but no individual gene showed a significant excess of variants of uncertain significance. CONCLUSION: These results underscore the etiological heterogeneity of OFCs and suggest sequencing could reduce the diagnostic gap in OFCs