Publications by authors named "Matthew E Hurles"

154 Publications

Non-coding region variants upstream of MEF2C cause severe developmental disorder through three distinct loss-of-function mechanisms.

Am J Hum Genet 2021 Jun 21;108(6):1083-1094. Epub 2021 May 21.

Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK; East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK.

Clinical genetic testing of protein-coding regions identifies a likely causative variant in only around half of developmental disorder (DD) cases. The contribution of regulatory variation in non-coding regions to rare disease, including DD, remains very poorly understood. We screened 9,858 probands from the Deciphering Developmental Disorders (DDD) study for de novo mutations in the 5' untranslated regions (5' UTRs) of genes within which variants have previously been shown to cause DD through a dominant haploinsufficient mechanism. We identified four single-nucleotide variants and two copy-number variants upstream of MEF2C in a total of ten individual probands. We developed multiple bespoke and orthogonal experimental approaches to demonstrate that these variants cause DD through three distinct loss-of-function mechanisms, disrupting transcription, translation, and/or protein function. These non-coding region variants represent 23% of likely diagnoses identified in MEF2C in the DDD cohort, but these would all be missed in standard clinical genetics approaches. Nonetheless, these variants are readily detectable in exome sequence data, with 30.7% of 5' UTR bases across all genes well covered in the DDD dataset. Our analyses show that non-coding variants upstream of genes within which coding variants are known to cause DD are an important cause of severe disease and demonstrate that analyzing 5' UTRs can increase diagnostic yield. We also show how non-coding variants can help inform both the disease-causing mechanism underlying protein-coding variants and dosage tolerance of the gene.
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http://dx.doi.org/10.1016/j.ajhg.2021.04.025DOI Listing
June 2021

The Diagnostic Yield of Prenatal Genetic Technologies in Congenital Heart Disease: A Prospective Cohort Study.

Fetal Diagn Ther 2021 Feb 5:1-8. Epub 2021 Feb 5.

West Midlands Fetal Medicine Centre, Birmingham Women's and Children's National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom.

Introduction: The objective was to evaluate: (i) the proportion of prenatally diagnosed congenital heart disease (CHD) associated with an abnormal quantitative fluorescence-PCR (QF-PCR), chromosome microarray (CMA), and exome sequencing (ES) result; and (ii) the diagnostic yield of these technologies based on CHD category and presence of extra-cardiac anomalies (ECAs).

Methods: This prospective cohort study was set across 12 UK foetal medicine centres. All cases underwent QF-PCR, CMA, and ES, and the diagnostic yield in n = 147 cases of prenatally diagnosed CHD was assessed.

Results: In 34.7% (n = 51/147), a genetic diagnosis was obtained. Using a stepwise testing strategy, the diagnostic yield for QF-PCR, CMA, and ES was 15.6% (n = 23/147), 13.7% (n = 17/124), and 10.2% (n = 11/107), respectively. Abnormal QF-PCR/shunt (septal) defects 31.4% (n = 11/35), p = 0.046, and abnormal CMA/conotruncal anomalies 22.7% (n = 10/44), p = 0.04, had significant associations. Monogenic variants were commonest in complex CHD 36.4% (n = 4/11). Multisystem CHD had a greater diagnostic yield overall compared to isolated OR 2.41 (95% CI, 1.1-5.1), particularly in association with brain and gastrointestinal tract anomalies. The proportion of variants of uncertain significance was 4.7% (n = 5/107) with ES, with none in the CMA group.

Conclusion: In the era of prenatal ES, there remains an important role for QF-PCR and CMA. Identification of monogenic pathologic variants further allows delineation of prognosis in CHD.
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http://dx.doi.org/10.1159/000512488DOI Listing
February 2021

The contribution of X-linked coding variation to severe developmental disorders.

Nat Commun 2021 01 27;12(1):627. Epub 2021 Jan 27.

Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.

Over 130 X-linked genes have been robustly associated with developmental disorders, and X-linked causes have been hypothesised to underlie the higher developmental disorder rates in males. Here, we evaluate the burden of X-linked coding variation in 11,044 developmental disorder patients, and find a similar rate of X-linked causes in males and females (6.0% and 6.9%, respectively), indicating that such variants do not account for the 1.4-fold male bias. We develop an improved strategy to detect X-linked developmental disorders and identify 23 significant genes, all of which were previously known, consistent with our inference that the vast majority of the X-linked burden is in known developmental disorder-associated genes. Importantly, we estimate that, in male probands, only 13% of inherited rare missense variants in known developmental disorder-associated genes are likely to be pathogenic. Our results demonstrate that statistical analysis of large datasets can refine our understanding of modes of inheritance for individual X-linked disorders.
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http://dx.doi.org/10.1038/s41467-020-20852-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840967PMC
January 2021

Evaluating variants classified as pathogenic in ClinVar in the DDD Study.

Genet Med 2021 03 5;23(3):571-575. Epub 2020 Nov 5.

Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.

Purpose: Automated variant filtering is an essential part of diagnostic genome-wide sequencing but may generate false negative results. We sought to investigate whether some previously identified pathogenic variants may be being routinely excluded by standard variant filtering pipelines.

Methods: We evaluated variants that were previously classified as pathogenic or likely pathogenic in ClinVar in known developmental disorder genes using exome sequence data from the Deciphering Developmental Disorders (DDD) study.

Results: Of these ClinVar pathogenic variants, 3.6% were identified among 13,462 DDD probands, and 1134/1352 (83.9%) had already been independently communicated to clinicians using DDD variant filtering pipelines as plausibly pathogenic. The remaining 218 variants failed consequence, inheritance, or other automated variant filters. Following clinical review of these additional variants, we were able to identify 112 variants in 107 (0.8%) DDD probands as potential diagnoses.

Conclusion: Lower minor allele frequency (<0.0005%) and higher gold star review status in ClinVar (>1 star) are good predictors of a previously identified variant being plausibly diagnostic for developmental disorders. However, around half of previously identified pathogenic variants excluded by automated variant filtering did not appear to be disease-causing, underlining the continued need for clinical evaluation of candidate variants as part of the diagnostic process.
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http://dx.doi.org/10.1038/s41436-020-01021-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7935711PMC
March 2021

Evidence for 28 genetic disorders discovered by combining healthcare and research data.

Nature 2020 10 14;586(7831):757-762. Epub 2020 Oct 14.

Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.

De novo mutations in protein-coding genes are a well-established cause of developmental disorders. However, genes known to be associated with developmental disorders account for only a minority of the observed excess of such de novo mutations. Here, to identify previously undescribed genes associated with developmental disorders, we integrate healthcare and research exome-sequence data from 31,058 parent-offspring trios of individuals with developmental disorders, and develop a simulation-based statistical test to identify gene-specific enrichment of de novo mutations. We identified 285 genes that were significantly associated with developmental disorders, including 28 that had not previously been robustly associated with developmental disorders. Although we detected more genes associated with developmental disorders, much of the excess of de novo mutations in protein-coding genes remains unaccounted for. Modelling suggests that more than 1,000 genes associated with developmental disorders have not yet been described, many of which are likely to be less penetrant than the currently known genes. Research access to clinical diagnostic datasets will be critical for completing the map of genes associated with developmental disorders.
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http://dx.doi.org/10.1038/s41586-020-2832-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7116826PMC
October 2020

Germline variants in HEY2 functional domains lead to congenital heart defects and thoracic aortic aneurysms.

Genet Med 2021 01 21;23(1):103-110. Epub 2020 Aug 21.

Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.

Purpose: In this study we aimed to establish the genetic cause of a myriad of cardiovascular defects prevalent in individuals from a genetically isolated population, who were found to share a common ancestor in 1728.

Methods: Trio genome sequencing was carried out in an index patient with critical congenital heart disease (CHD); family members had either exome or Sanger sequencing. To confirm enrichment, we performed a gene-based association test and meta-analysis in two independent validation cohorts: one with 2685 CHD cases versus 4370 . These controls were also ancestry-matched (same as FTAA controls), and the other with 326 cases with familial thoracic aortic aneurysms (FTAA) and dissections versus 570 ancestry-matched controls. Functional consequences of identified variants were evaluated using expression studies.

Results: We identified a loss-of-function variant in the Notch target transcription factor-encoding gene HEY2. The homozygous state (n = 3) causes life-threatening congenital heart defects, while 80% of heterozygous carriers (n = 20) had cardiovascular defects, mainly CHD and FTAA of the ascending aorta. We confirm enrichment of rare risk variants in HEY2 functional domains after meta-analysis (MetaSKAT p = 0.018). Furthermore, we show that several identified variants lead to dysregulation of repression by HEY2.

Conclusion: A homozygous germline loss-of-function variant in HEY2 leads to critical CHD. The majority of heterozygotes show a myriad of cardiovascular defects.
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http://dx.doi.org/10.1038/s41436-020-00939-4DOI Listing
January 2021

Dynamic changes in the epigenomic landscape regulate human organogenesis and link to developmental disorders.

Nat Commun 2020 08 6;11(1):3920. Epub 2020 Aug 6.

Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.

How the genome activates or silences transcriptional programmes governs organ formation. Little is known in human embryos undermining our ability to benchmark the fidelity of stem cell differentiation or cell programming, or interpret the pathogenicity of noncoding variation. Here, we study histone modifications across thirteen tissues during human organogenesis. We integrate the data with transcription to build an overview of how the human genome differentially regulates alternative organ fates including by repression. Promoters from nearly 20,000 genes partition into discrete states. Key developmental gene sets are actively repressed outside of the appropriate organ without obvious bivalency. Candidate enhancers, functional in zebrafish, allow imputation of tissue-specific and shared patterns of transcription factor binding. Overlaying more than 700 noncoding mutations from patients with developmental disorders allows correlation to unanticipated target genes. Taken together, the data provide a comprehensive genomic framework for investigating normal and abnormal human development.
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http://dx.doi.org/10.1038/s41467-020-17305-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7413392PMC
August 2020

Population Structure, Stratification, and Introgression of Human Structural Variation.

Cell 2020 07 11;182(1):189-199.e15. Epub 2020 Jun 11.

Wellcome Sanger Institute, Hinxton CB10 1SA, UK. Electronic address:

Structural variants contribute substantially to genetic diversity and are important evolutionarily and medically, but they are still understudied. Here we present a comprehensive analysis of structural variation in the Human Genome Diversity panel, a high-coverage dataset of 911 samples from 54 diverse worldwide populations. We identify, in total, 126,018 variants, 78% of which were not identified in previous global sequencing projects. Some reach high frequency and are private to continental groups or even individual populations, including regionally restricted runaway duplications and putatively introgressed variants from archaic hominins. By de novo assembly of 25 genomes using linked-read sequencing, we discover 1,643 breakpoint-resolved unique insertions, in aggregate accounting for 1.9 Mb of sequence absent from the GRCh38 reference. Our results illustrate the limitation of a single human reference and the need for high-quality genomes from diverse populations to fully discover and understand human genetic variation.
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http://dx.doi.org/10.1016/j.cell.2020.05.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7369638PMC
July 2020

Whole-genome sequencing of a sporadic primary immunodeficiency cohort.

Nature 2020 07 6;583(7814):90-95. Epub 2020 May 6.

Institute of Immunity and Transplantation, University College London, London, UK.

Primary immunodeficiency (PID) is characterized by recurrent and often life-threatening infections, autoimmunity and cancer, and it poses major diagnostic and therapeutic challenges. Although the most severe forms of PID are identified in early childhood, most patients present in adulthood, typically with no apparent family history and a variable clinical phenotype of widespread immune dysregulation: about 25% of patients have autoimmune disease, allergy is prevalent and up to 10% develop lymphoid malignancies. Consequently, in sporadic (or non-familial) PID genetic diagnosis is difficult and the role of genetics is not well defined. Here we address these challenges by performing whole-genome sequencing in a large PID cohort of 1,318 participants. An analysis of the coding regions of the genome in 886 index cases of PID found that disease-causing mutations in known genes that are implicated in monogenic PID occurred in 10.3% of these patients, and a Bayesian approach (BeviMed) identified multiple new candidate PID-associated genes, including IVNS1ABP. We also examined the noncoding genome, and found deletions in regulatory regions that contribute to disease causation. In addition, we used a genome-wide association study to identify loci that are associated with PID, and found evidence for the colocalization of-and interplay between-novel high-penetrance monogenic variants and common variants (at the PTPN2 and SOCS1 loci). This begins to explain the contribution of common variants to the variable penetrance and phenotypic complexity that are observed in PID. Thus, using a cohort-based whole-genome-sequencing approach in the diagnosis of PID can increase diagnostic yield and further our understanding of the key pathways that influence immune responsiveness in humans.
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http://dx.doi.org/10.1038/s41586-020-2265-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7334047PMC
July 2020

Exome Sequencing for Prenatal Detection of Genetic Abnormalities in Fetal Ultrasound Anomalies: An Economic Evaluation.

Fetal Diagn Ther 2020 21;47(7):554-564. Epub 2020 Jan 21.

Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom,

Introduction: In light of the prospective Prenatal Assessment of Genomes and Exomes (PAGE) study, this paper aimed to determine the additional costs of using exome sequencing (ES) alongside or in place of chromosomal microarray (CMA) in a fetus with an identified congenital anomaly.

Methods: A decision tree was populated using data from a prospective cohort of women undergoing invasive diagnostic testing. Four testing strategies were evaluated: CMA, ES, CMA followed by ES ("stepwise"); CMA and ES combined.

Results: When ES is priced at GBP 2,100 (EUR 2,407/USD 2,694), performing ES alone prenatally would cost a further GBP 31,410 (EUR 36,001/USD 40,289) per additional genetic diagnosis, whereas the stepwise would cost a further GBP 24,657 (EUR 28,261/USD 31,627) per additional genetic diagnosis. When ES is priced at GBP 966 (EUR 1,107/USD 1,239), performing ES alone prenatally would cost a further GBP 11,532 (EUR 13,217/USD 14,792) per additional genetic diagnosis, whereas the stepwise would cost a further additional GBP 11,639 (EUR 13,340/USD 14,929) per additional genetic diagnosis. The sub-group analysis suggests that performing stepwise on cases indicative of multiple anomalies at ultrasound scan (USS) compared to cases indicative of a single anomaly, is more cost-effective compared to using ES alone.

Discussion/conclusion: Performing ES alongside CMA is more cost-effective than ES alone, which can potentially lead to improvements in pregnancy management. The direct effects of test results on pregnancy outcomes were not examined; therefore, further research is recommended to examine changes on the projected incremental cost-effectiveness ratios.
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http://dx.doi.org/10.1159/000504976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7446299PMC
May 2021

A brief history of human disease genetics.

Nature 2020 01 8;577(7789):179-189. Epub 2020 Jan 8.

Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK.

A primary goal of human genetics is to identify DNA sequence variants that influence biomedical traits, particularly those related to the onset and progression of human disease. Over the past 25 years, progress in realizing this objective has been transformed by advances in technology, foundational genomic resources and analytical tools, and by access to vast amounts of genotype and phenotype data. Genetic discoveries have substantially improved our understanding of the mechanisms responsible for many rare and common diseases and driven development of novel preventative and therapeutic strategies. Medical innovation will increasingly focus on delivering care tailored to individual patterns of genetic predisposition.
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http://dx.doi.org/10.1038/s41586-019-1879-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405896PMC
January 2020

Finding Diagnostically Useful Patterns in Quantitative Phenotypic Data.

Am J Hum Genet 2019 11 10;105(5):933-946. Epub 2019 Oct 10.

Wellcome Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK.

Trio-based whole-exome sequence (WES) data have established confident genetic diagnoses in ∼40% of previously undiagnosed individuals recruited to the Deciphering Developmental Disorders (DDD) study. Here we aim to use the breadth of phenotypic information recorded in DDD to augment diagnosis and disease variant discovery in probands. Median Euclidean distances (mEuD) were employed as a simple measure of similarity of quantitative phenotypic data within sets of ≥10 individuals with plausibly causative de novo mutations (DNM) in 28 different developmental disorder genes. 13/28 (46.4%) showed significant similarity for growth or developmental milestone metrics, 10/28 (35.7%) showed similarity in HPO term usage, and 12/28 (43%) showed no phenotypic similarity. Pairwise comparisons of individuals with high-impact inherited variants to the 32 individuals with causative DNM in ANKRD11 using only growth z-scores highlighted 5 likely causative inherited variants and two unrecognized DNM resulting in an 18% diagnostic uplift for this gene. Using an independent approach, naive Bayes classification of growth and developmental data produced reasonably discriminative models for the 24 DNM genes with sufficiently complete data. An unsupervised naive Bayes classification of 6,993 probands with WES data and sufficient phenotypic information defined 23 in silico syndromes (ISSs) and was used to test a "phenotype first" approach to the discovery of causative genotypes using WES variants strictly filtered on allele frequency, mutation consequence, and evidence of constraint in humans. This highlighted heterozygous de novo nonsynonymous variants in SPTBN2 as causative in three DDD probands.
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http://dx.doi.org/10.1016/j.ajhg.2019.09.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6848993PMC
November 2019

Contribution of retrotransposition to developmental disorders.

Nat Commun 2019 10 11;10(1):4630. Epub 2019 Oct 11.

Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, Hinxton, CB10 1SA, UK.

Mobile genetic Elements (MEs) are segments of DNA which can copy themselves and other transcribed sequences through the process of retrotransposition (RT). In humans several disorders have been attributed to RT, but the role of RT in severe developmental disorders (DD) has not yet been explored. Here we identify RT-derived events in 9738 exome sequenced trios with DD-affected probands. We ascertain 9 de novo MEs, 4 of which are likely causative of the patient's symptoms (0.04%), as well as 2 de novo gene retroduplications. Beyond identifying likely diagnostic RT events, we estimate genome-wide germline ME mutation rate and selective constraint and demonstrate that coding RT events have signatures of purifying selection equivalent to those of truncating mutations. Overall, our analysis represents a comprehensive interrogation of the impact of retrotransposition on protein coding genes and a framework for future evolutionary and disease studies.
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http://dx.doi.org/10.1038/s41467-019-12520-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6789007PMC
October 2019

Similarities and differences in patterns of germline mutation between mice and humans.

Nat Commun 2019 09 6;10(1):4053. Epub 2019 Sep 6.

Wellcome Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.

Whole genome sequencing (WGS) studies have estimated the human germline mutation rate per basepair per generation (~1.2 × 10) to be higher than in mice (3.5-5.4 × 10). In humans, most germline mutations are paternal in origin and numbers of mutations per offspring increase with paternal and maternal age. Here we estimate germline mutation rates and spectra in six multi-sibling mouse pedigrees and compare to three multi-sibling human pedigrees. In both species we observe a paternal mutation bias, a parental age effect, and a highly mutagenic first cell division contributing to the embryo. We also observe differences between species in mutation spectra, in mutation rates per cell division, and in the parental bias of mutations in early embryogenesis. These differences between species likely result from both species-specific differences in cellular genealogies of the germline, as well as biological differences within the same stage of embryogenesis or gametogenesis.
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http://dx.doi.org/10.1038/s41467-019-12023-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6731245PMC
September 2019

Paternal exposure to benzo(a)pyrene induces genome-wide mutations in mouse offspring.

Commun Biol 2019 20;2:228. Epub 2019 Jun 20.

2Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada.

Understanding the effects of environmental exposures on germline mutation rates has been a decades-long pursuit in genetics. We used next-generation sequencing and comparative genomic hybridization arrays to investigate genome-wide mutations in the offspring of male mice exposed to benzo(a)pyrene (BaP), a common environmental pollutant. We demonstrate that offspring developing from sperm exposed during the mitotic or post-mitotic phases of spermatogenesis have significantly more de novo single nucleotide variants (1.8-fold;  < 0.01) than controls. Both phases of spermatogenesis are susceptible to the induction of heritable mutations, although mutations arising from post-fertilization events are more common after post-mitotic exposure. In addition, the mutation spectra in sperm and offspring of BaP-exposed males are consistent. Finally, we report a significant increase in transmitted copy number duplications ( = 0.001) in BaP-exposed sires. Our study demonstrates that germ cell mutagen exposures induce genome-wide mutations in the offspring that may be associated with adverse health outcomes.
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http://dx.doi.org/10.1038/s42003-019-0476-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6586636PMC
April 2020

Exome-wide assessment of the functional impact and pathogenicity of multinucleotide mutations.

Genome Res 2019 07 21;29(7):1047-1056. Epub 2019 Jun 21.

Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, United Kingdom.

Approximately 2% of de novo single-nucleotide variants (SNVs) appear as part of clustered mutations that create multinucleotide variants (MNVs). MNVs are an important source of genomic variability as they are more likely to alter an encoded protein than a SNV, which has important implications in disease as well as evolution. Previous studies of MNVs have focused on their mutational origins and have not systematically evaluated their functional impact and contribution to disease. We identified 69,940 MNVs and 91 de novo MNVs in 6688 exome-sequenced parent-offspring trios from the Deciphering Developmental Disorders Study comprising families with severe developmental disorders. We replicated the previously described MNV mutational signatures associated with DNA polymerase zeta, an error-prone translesion polymerase, and the APOBEC family of DNA deaminases. We estimate the simultaneous MNV germline mutation rate to be 1.78 × 10 mutations per base pair per generation. We found that most MNVs within a single codon create a missense change that could not have been created by a SNV. MNV-induced missense changes were, on average, more physicochemically divergent, were more depleted in highly constrained genes (pLI ≥ 0.9), and were under stronger purifying selection compared with SNV-induced missense changes. We found that de novo MNVs were significantly enriched in genes previously associated with developmental disorders in affected children. This shows that MNVs can be more damaging than SNVs even when both induce missense changes, and are an important variant type to consider in relation to human disease.
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http://dx.doi.org/10.1101/gr.239756.118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6633265PMC
July 2019

VarMap: a web tool for mapping genomic coordinates to protein sequence and structure and retrieving protein structural annotations.

Bioinformatics 2019 11;35(22):4854-4856

European Molecular Biology Laboratory-European Bioinformatics Institute (EMBL-EBI), Hinxton, CB10 1SD, UK.

Motivation: Understanding the protein structural context and patterning on proteins of genomic variants can help to separate benign from pathogenic variants and reveal molecular consequences. However, mapping genomic coordinates to protein structures is non-trivial, complicated by alternative splicing and transcript evidence.

Results: Here we present VarMap, a web tool for mapping a list of chromosome coordinates to canonical UniProt sequences and associated protein 3D structures, including validation checks, and annotating them with structural information.

Availability And Implementation: https://www.ebi.ac.uk/thornton-srv/databases/VarMap.

Supplementary Information: Supplementary data are available at Bioinformatics online.
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http://dx.doi.org/10.1093/bioinformatics/btz482DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6853667PMC
November 2019

Flexible and scalable diagnostic filtering of genomic variants using G2P with Ensembl VEP.

Nat Commun 2019 05 30;10(1):2373. Epub 2019 May 30.

MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, EH4 2XU, UK.

We aimed to develop an efficient, flexible and scalable approach to diagnostic genome-wide sequence analysis of genetically heterogeneous clinical presentations. Here we present G2P ( www.ebi.ac.uk/gene2phenotype ) as an online system to establish, curate and distribute datasets for diagnostic variant filtering via association of allelic requirement and mutational consequence at a defined locus with phenotypic terms, confidence level and evidence links. An extension to Ensembl Variant Effect Predictor (VEP), VEP-G2P was used to filter both disease-associated and control whole exome sequence (WES) with Developmental Disorders G2P (G2P; 2044 entries). VEP-G2P shows a sensitivity/precision of 97.3%/33% for de novo and 81.6%/22.7% for inherited pathogenic genotypes respectively. Many of the missing genotypes are likely false-positive pathogenic assignments. The expected number and discriminative features of background genotypes are defined using control WES. Using only human genetic data VEP-G2P performs well compared to other freely-available diagnostic systems and future phenotypic matching capabilities should further enhance performance.
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http://dx.doi.org/10.1038/s41467-019-10016-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6542828PMC
May 2019

Prenatal exome sequencing analysis in fetal structural anomalies detected by ultrasonography (PAGE): a cohort study.

Lancet 2019 02 31;393(10173):747-757. Epub 2019 Jan 31.

Department of Clinical Genetics, St Michael's Hospital, University Hospitals Bristol, Bristol, UK.

Background: Fetal structural anomalies, which are detected by ultrasonography, have a range of genetic causes, including chromosomal aneuploidy, copy number variations (CNVs; which are detectable by chromosomal microarrays), and pathogenic sequence variants in developmental genes. Testing for aneuploidy and CNVs is routine during the investigation of fetal structural anomalies, but there is little information on the clinical usefulness of genome-wide next-generation sequencing in the prenatal setting. We therefore aimed to evaluate the proportion of fetuses with structural abnormalities that had identifiable variants in genes associated with developmental disorders when assessed with whole-exome sequencing (WES).

Methods: In this prospective cohort study, two groups in Birmingham and London recruited patients from 34 fetal medicine units in England and Scotland. We used whole-exome sequencing (WES) to evaluate the presence of genetic variants in developmental disorder genes (diagnostic genetic variants) in a cohort of fetuses with structural anomalies and samples from their parents, after exclusion of aneuploidy and large CNVs. Women were eligible for inclusion if they were undergoing invasive testing for identified nuchal translucency or structural anomalies in their fetus, as detected by ultrasound after 11 weeks of gestation. The partners of these women also had to consent to participate. Sequencing results were interpreted with a targeted virtual gene panel for developmental disorders that comprised 1628 genes. Genetic results related to fetal structural anomaly phenotypes were then validated and reported postnatally. The primary endpoint, which was assessed in all fetuses, was the detection of diagnostic genetic variants considered to have caused the fetal developmental anomaly.

Findings: The cohort was recruited between Oct 22, 2014, and June 29, 2017, and clinical data were collected until March 31, 2018. After exclusion of fetuses with aneuploidy and CNVs, 610 fetuses with structural anomalies and 1202 matched parental samples (analysed as 596 fetus-parental trios, including two sets of twins, and 14 fetus-parent dyads) were analysed by WES. After bioinformatic filtering and prioritisation according to allele frequency and effect on protein and inheritance pattern, 321 genetic variants (representing 255 potential diagnoses) were selected as potentially pathogenic genetic variants (diagnostic genetic variants), and these variants were reviewed by a multidisciplinary clinical review panel. A diagnostic genetic variant was identified in 52 (8·5%; 95% CI 6·4-11·0) of 610 fetuses assessed and an additional 24 (3·9%) fetuses had a variant of uncertain significance that had potential clinical usefulness. Detection of diagnostic genetic variants enabled us to distinguish between syndromic and non-syndromic fetal anomalies (eg, congenital heart disease only vs a syndrome with congenital heart disease and learning disability). Diagnostic genetic variants were present in 22 (15·4%) of 143 fetuses with multisystem anomalies (ie, more than one fetal structural anomaly), nine (11·1%) of 81 fetuses with cardiac anomalies, and ten (15·4%) of 65 fetuses with skeletal anomalies; these phenotypes were most commonly associated with diagnostic variants. However, diagnostic genetic variants were least common in fetuses with isolated increased nuchal translucency (≥4·0 mm) in the first trimester (in three [3·2%] of 93 fetuses).

Interpretation: WES facilitates genetic diagnosis of fetal structural anomalies, which enables more accurate predictions of fetal prognosis and risk of recurrence in future pregnancies. However, the overall detection of diagnostic genetic variants in a prospectively ascertained cohort with a broad range of fetal structural anomalies is lower than that suggested by previous smaller-scale studies of fewer phenotypes. WES improved the identification of genetic disorders in fetuses with structural abnormalities; however, before clinical implementation, careful consideration should be given to case selection to maximise clinical usefulness.

Funding: UK Department of Health and Social Care and The Wellcome Trust.
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http://dx.doi.org/10.1016/S0140-6736(18)31940-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386638PMC
February 2019

Pathogenicity and selective constraint on variation near splice sites.

Genome Res 2019 02 26;29(2):159-170. Epub 2018 Dec 26.

Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom.

Mutations that perturb normal pre-mRNA splicing are significant contributors to human disease. We used exome sequencing data from 7833 probands with developmental disorders (DDs) and their unaffected parents, as well as more than 60,000 aggregated exomes from the Exome Aggregation Consortium, to investigate selection around the splice sites and quantify the contribution of splicing mutations to DDs. Patterns of purifying selection, a deficit of variants in highly constrained genes in healthy subjects, and excess de novo mutations in patients highlighted particular positions within and around the consensus splice site of greater functional relevance. By using mutational burden analyses in this large cohort of proband-parent trios, we could estimate in an unbiased manner the relative contributions of mutations at canonical dinucleotides (73%) and flanking noncanonical positions (27%), and calculate the positive predictive value of pathogenicity for different classes of mutations. We identified 18 patients with likely diagnostic de novo mutations in dominant DD-associated genes at noncanonical positions in splice sites. We estimate 35%-40% of pathogenic variants in noncanonical splice site positions are missing from public databases.
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http://dx.doi.org/10.1101/gr.238444.118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360807PMC
February 2019

Quantifying the contribution of recessive coding variation to developmental disorders.

Science 2018 12 8;362(6419):1161-1164. Epub 2018 Nov 8.

Clinical Genetics, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK.

We estimated the genome-wide contribution of recessive coding variation in 6040 families from the Deciphering Developmental Disorders study. The proportion of cases attributable to recessive coding variants was 3.6% in patients of European ancestry, compared with 50% explained by de novo coding mutations. It was higher (31%) in patients with Pakistani ancestry, owing to elevated autozygosity. Half of this recessive burden is attributable to known genes. We identified two genes not previously associated with recessive developmental disorders, and , and functionally validated them with mouse and cellular models. Our results suggest that recessive coding variants account for a small fraction of currently undiagnosed nonconsanguineous individuals, and that the role of noncoding variants, incomplete penetrance, and polygenic mechanisms need further exploration.
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http://dx.doi.org/10.1126/science.aar6731DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726470PMC
December 2018

Molecular autopsy by trio exome sequencing (ES) and postmortem examination in fetuses and neonates with prenatally identified structural anomalies.

Genet Med 2019 05 8;21(5):1065-1073. Epub 2018 Oct 8.

West Midlands Fetal Medicine Centre, Birmingham Women's & Children's NHS Foundation Trust, Birmingham, UK.

Purpose: To determine the diagnostic yield of combined exome sequencing (ES) and autopsy in fetuses/neonates with prenatally identified structural anomalies resulting in termination of pregnancy, intrauterine, neonatal, or early infant death.

Methods: ES was undertaken in 27 proband/parent trios following full autopsy. Candidate pathogenic variants were classified by a multidisciplinary clinical review panel using American College of Medical Genetics and Genomics (ACMG) guidelines.

Results: A genetic diagnosis was established in ten cases (37%). Pathogenic/likely pathogenic variants were identified in nine different genes including four de novo autosomal dominant, three homozygous autosomal recessive, two compound heterozygous autosomal recessive, and one X-linked. KMT2D variants (associated with Kabuki syndrome postnatally) occurred in two cases. Pathogenic variants were identified in 5/13 (38%) cases with multisystem anomalies, in 2/4 (50%) cases with fetal akinesia deformation sequence, and in 1/4 (25%) cases each with cardiac and brain anomalies and hydrops fetalis. No pathogenic variants were detected in fetuses with genitourinary (1), skeletal (1), or abdominal (1) abnormalities.

Conclusion: This cohort demonstrates the clinical utility of molecular autopsy with ES to identify an underlying genetic cause in structurally abnormal fetuses/neonates. These molecular findings provided parents with an explanation of the developmental abnormality, delineated the recurrence risks, and assisted the management of subsequent pregnancies.
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http://dx.doi.org/10.1038/s41436-018-0298-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6752266PMC
May 2019

Common genetic variants contribute to risk of rare severe neurodevelopmental disorders.

Nature 2018 10 26;562(7726):268-271. Epub 2018 Sep 26.

Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.

There are thousands of rare human disorders that are caused by single deleterious, protein-coding genetic variants. However, patients with the same genetic defect can have different clinical presentations, and some individuals who carry known disease-causing variants can appear unaffected. Here, to understand what explains these differences, we study a cohort of 6,987 children assessed by clinical geneticists to have severe neurodevelopmental disorders such as global developmental delay and autism, often in combination with abnormalities of other organ systems. Although the genetic causes of these neurodevelopmental disorders are expected to be almost entirely monogenic, we show that 7.7% of variance in risk is attributable to inherited common genetic variation. We replicated this genome-wide common variant burden by showing, in an independent sample of 728 trios (comprising a child plus both parents) from the same cohort, that this burden is over-transmitted from parents to children with neurodevelopmental disorders. Our common-variant signal is significantly positively correlated with genetic predisposition to lower educational attainment, decreased intelligence and risk of schizophrenia. We found that common-variant risk was not significantly different between individuals with and without a known protein-coding diagnostic variant, which suggests that common-variant risk affects patients both with and without a monogenic diagnosis. In addition, previously published common-variant scores for autism, height, birth weight and intracranial volume were all correlated with these traits within our cohort, which suggests that phenotypic expression in individuals with monogenic disorders is affected by the same variants as in the general population. Our results demonstrate that common genetic variation affects both overall risk and clinical presentation in neurodevelopmental disorders that are typically considered to be monogenic.
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http://dx.doi.org/10.1038/s41586-018-0566-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726472PMC
October 2018

Analysis of novel missense ATR mutations reveals new splicing defects underlying Seckel syndrome.

Hum Mutat 2018 12 24;39(12):1847-1853. Epub 2018 Sep 24.

Centre for Chromosome Biology, National University of Ireland in Galway, Galway, Ireland.

Ataxia Telangiectasia and Rad3 related (ATR) is one of the main regulators of the DNA damage response. It coordinates cell cycle checkpoint activation, replication fork stability, restart and origin firing to maintain genome integrity. Mutations of the ATR gene have been reported in Seckel patients, who suffer from a rare genetic disease characterized by severe microcephaly and growth retardation. Here, we report the case of a Seckel patient with compound heterozygous mutations in ATR. One allele has an intronic mutation affecting splicing of neighboring exons, the other an exonic missense mutation, producing the variant p.Lys1665Asn, of unknown pathogenicity. We have modeled this novel missense mutation, as well as a previously described missense mutation p.Met1159Ile, and assessed their effect on ATR function. Interestingly, our data indicate that both missense mutations have no direct effect on protein function, but rather result in defective ATR splicing. These results emphasize the importance of splicing mutations in Seckel Syndrome.
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http://dx.doi.org/10.1002/humu.23648DOI Listing
December 2018

De novo mutations in regulatory elements in neurodevelopmental disorders.

Nature 2018 03 21;555(7698):611-616. Epub 2018 Mar 21.

Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK.

We previously estimated that 42% of patients with severe developmental disorders carry pathogenic de novo mutations in coding sequences. The role of de novo mutations in regulatory elements affecting genes associated with developmental disorders, or other genes, has been essentially unexplored. We identified de novo mutations in three classes of putative regulatory elements in almost 8,000 patients with developmental disorders. Here we show that de novo mutations in highly evolutionarily conserved fetal brain-active elements are significantly and specifically enriched in neurodevelopmental disorders. We identified a significant twofold enrichment of recurrently mutated elements. We estimate that, genome-wide, 1-3% of patients without a diagnostic coding variant carry pathogenic de novo mutations in fetal brain-active regulatory elements and that only 0.15% of all possible mutations within highly conserved fetal brain-active elements cause neurodevelopmental disorders with a dominant mechanism. Our findings represent a robust estimate of the contribution of de novo mutations in regulatory elements to this genetically heterogeneous set of disorders, and emphasize the importance of combining functional and evolutionary evidence to identify regulatory causes of genetic disorders.
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http://dx.doi.org/10.1038/nature25983DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5912909PMC
March 2018

Making new genetic diagnoses with old data: iterative reanalysis and reporting from genome-wide data in 1,133 families with developmental disorders.

Genet Med 2018 10 11;20(10):1216-1223. Epub 2018 Jan 11.

Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.

Purpose: Given the rapid pace of discovery in rare disease genomics, it is likely that improvements in diagnostic yield can be made by systematically reanalyzing previously generated genomic sequence data in light of new knowledge.

Methods: We tested this hypothesis in the United Kingdom-wide Deciphering Developmental Disorders study, where in 2014 we reported a diagnostic yield of 27% through whole-exome sequencing of 1,133 children with severe developmental disorders and their parents. We reanalyzed existing data using improved variant calling methodologies, novel variant detection algorithms, updated variant annotation, evidence-based filtering strategies, and newly discovered disease-associated genes.

Results: We are now able to diagnose an additional 182 individuals, taking our overall diagnostic yield to 454/1,133 (40%), and another 43 (4%) have a finding of uncertain clinical significance. The majority of these new diagnoses are due to novel developmental disorder-associated genes discovered since our original publication.

Conclusion: This study highlights the importance of coupling large-scale research with clinical practice, and of discussing the possibility of iterative reanalysis and recontact with patients and health professionals at an early stage. We estimate that implementing parent-offspring whole-exome sequencing as a first-line diagnostic test for developmental disorders would diagnose >50% of patients.
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http://dx.doi.org/10.1038/gim.2017.246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5912505PMC
October 2018

Detection of structural mosaicism from targeted and whole-genome sequencing data.

Genome Res 2017 10 30;27(10):1704-1714. Epub 2017 Aug 30.

Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom.

Structural mosaic abnormalities are large post-zygotic mutations present in a subset of cells and have been implicated in developmental disorders and cancer. Such mutations have been conventionally assessed in clinical diagnostics using cytogenetic or microarray testing. Modern disease studies rely heavily on exome sequencing, yet an adequate method for the detection of structural mosaicism using targeted sequencing data is lacking. Here, we present a method, called MrMosaic, to detect structural mosaic abnormalities using deviations in allele fraction and read coverage from next-generation sequencing data. Whole-exome sequencing (WES) and whole-genome sequencing (WGS) simulations were used to calculate detection performance across a range of mosaic event sizes, types, clonalities, and sequencing depths. The tool was applied to 4911 patients with undiagnosed developmental disorders, and 11 events among nine patients were detected. For eight of these 11 events, mosaicism was observed in saliva but not blood, suggesting that assaying blood alone would miss a large fraction, possibly >50%, of mosaic diagnostic chromosomal rearrangements.
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http://dx.doi.org/10.1101/gr.212373.116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630034PMC
October 2017

Estimating the human mutation rate from autozygous segments reveals population differences in human mutational processes.

Nat Commun 2017 08 21;8(1):303. Epub 2017 Aug 21.

Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.

Heterozygous mutations within homozygous sequences descended from a recent common ancestor offer a way to ascertain de novo mutations across multiple generations. Using exome sequences from 3222 British-Pakistani individuals with high parental relatedness, we estimate a mutation rate of 1.45 ± 0.05 × 10 per base pair per generation in autosomal coding sequence, with a corresponding non-crossover gene conversion rate of 8.75 ± 0.05 × 10 per base pair per generation. This is at the lower end of exome mutation rates previously estimated in parent-offspring trios, suggesting that post-zygotic mutations contribute little to the human germ-line mutation rate. We find frequent recurrence of mutations at polymorphic CpG sites, and an increase in C to T mutations in a 5' CCG 3' to 5' CTG 3' context in the Pakistani population compared to Europeans, suggesting that mutational processes have evolved rapidly between human populations.Estimates of human mutation rates differ substantially based on the approach. Here, the authors present a multi-generational estimate from the autozygous segment in a non-European population that gives insight into the contribution of post-zygotic mutations and population-specific mutational processes.
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http://dx.doi.org/10.1038/s41467-017-00323-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566399PMC
August 2017

International Cooperation to Enable the Diagnosis of All Rare Genetic Diseases.

Am J Hum Genet 2017 May;100(5):695-705

Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.

Provision of a molecularly confirmed diagnosis in a timely manner for children and adults with rare genetic diseases shortens their "diagnostic odyssey," improves disease management, and fosters genetic counseling with respect to recurrence risks while assuring reproductive choices. In a general clinical genetics setting, the current diagnostic rate is approximately 50%, but for those who do not receive a molecular diagnosis after the initial genetics evaluation, that rate is much lower. Diagnostic success for these more challenging affected individuals depends to a large extent on progress in the discovery of genes associated with, and mechanisms underlying, rare diseases. Thus, continued research is required for moving toward a more complete catalog of disease-related genes and variants. The International Rare Diseases Research Consortium (IRDiRC) was established in 2011 to bring together researchers and organizations invested in rare disease research to develop a means of achieving molecular diagnosis for all rare diseases. Here, we review the current and future bottlenecks to gene discovery and suggest strategies for enabling progress in this regard. Each successful discovery will define potential diagnostic, preventive, and therapeutic opportunities for the corresponding rare disease, enabling precision medicine for this patient population.
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http://dx.doi.org/10.1016/j.ajhg.2017.04.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5420351PMC
May 2017