bioRxiv Science⌕ Search

bioRxiv · 10.1101/255299

A meta-analysis of the diagnostic sensitivity and clinical utility of genome sequencing, exome sequencing and chromosomal microarray in children with suspected genetic diseases

Abstract

IMPORTANCEGenetic diseases are a leading cause of childhood mortality. Whole genome sequencing (WGS) and whole exome sequencing (WES) are relatively new methods for diagnosing genetic diseases.\n\nOBJECTIVESCompare the diagnostic sensitivity (rate of causative, pathogenic or likely pathogenic genotypes in known disease genes) and rate of clinical utility (proportion in whom medical or surgical management was changed by diagnosis) of WGS, WES, and chromosomal microarrays (CMA) in children with suspected genetic diseases.\n\nDATA SOURCES AND STUDY SELECTIONSystematic review of the literature (January 2011 - August 2017) for studies of diagnostic sensitivity and/or clinical utility of WGS, WES, and/or CMA in children with suspected genetic diseases. 2% of identified studies met selection criteria.\n\nDATA EXTRACTION AND SYNTHESISTwo investigators extracted data independently following MOOSE/PRISMA guidelines.\n\nMAIN OUTCOMES AND MEASURESPooled rates and 95% Cl were estimated with a random-effects model. Metaanalysis of the rate of diagnosis was based on test type, family structure, and site of testing.\n\nRESULTSIn 36 observational series and one randomized control trial, comprising 20,068 children, the diagnostic sensitivity of WGS (0.41, 95% Cl 0.34-0.48, I2=44%) and WES (0.35, 95% Cl 0.31-0.39, I2=85%) were qualitatively greater than CMA (0.10, 95% Cl 0.08-0.12, I2=81%). Subgroup meta-analyses showed that the diagnostic sensitivity of WGS was significantly greater than CMA in studies published in 2017 (P<.0001, I2=13% and I2=40%, respectively), and the diagnostic sensitivity of WES was significantly greater than CMA in studies featuring within-cohort comparisons (P<001, I2=36%). Evidence for a significant difference in the diagnostic sensitivity of WGS and WES was lacking. In studies featuring within-cohort comparisons of singleton and trio WGS/WES, the likelihood of diagnosis was significantly greater for trios (odds ratio 2.04, 95% Cl 1.62-2.56, I2=12%; P<.0001). The diagnostic sensitivity of WGS/WES with hospital-based interpretation (0.41, 95% Cl 0.38-0.45, I2=50%) was qualitatively higher than that of reference laboratories (0.28, 95% Cl 0.24-0.32, I2=81%); this difference was significant in meta-analysis of studies published in 2017 (P=.004, I2=34% and I2=26%, respectively). The rates of clinical utility of WGS (0.27, 95% Cl 0.17-0.40, I2=54%) and WES (0.18, 95% Cl 0.13-0.24, I2-77%) were higher than CMA (0.06, 95% Cl 0.05-0.07, I2=42%); this difference was significant in meta-analysis of WGS vs CMA (P<.0001).\n\nCONCLUSIONS AND RELEVANCEIn children with suspected genetic diseases, the diagnostic sensitivity and rate of clinical utility of WGS/WES were greater than CMA. Subgroups with higher WGS/WES diagnostic sensitivity were trios and those receiving hospital-based interpretation. WGS/WES should be considered a first-line genomic test for children with suspected genetic diseases.\n\nKey PointsO_ST_ABSQuestionC_ST_ABSWhat is the relative diagnostic sensitivity and clinical utility of different genome tests in children with suspected genetic diseases?\n\nFindingsWhole genome sequencing had greater diagnostic sensitivity and clinical utility than chromosomal microarrays. Testing parent-child trios had greater diagnostic sensitivity than proband singletons. Hospital-based testing had greater diagnostic sensitivity than reference laboratories.\n\nMeaningTrio genomic sequencing is the most sensitive diagnostic test for children with suspected genetic diseases.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Clark, M. M., Stark, Z., Farnaes, L., Tan, T. Y., White, S. M., Dimmock, D., Kingsmore, S. F.. 2018-01-30. A meta-analysis of the diagnostic sensitivity and clinical utility of genome sequencing, exome sequencing and chromosomal microarray in children with suspected genetic diseases. https://doi.org/10.1101/255299

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

The Braarudosphaera bigelowii genome reveals cellular remodeling around a nitrogen-fixing organelle

Braarudosphaera bigelowii hosts the nitrogen-fixing cyanobacterial organelle UCYN-A, or the nitroplast, but the absence of a reference genome has limited investigation of the genomic features accompanying this association. Here, we present nuclear and organellar genome resources for the cultured B. bigelowii strain FR-21. The assembly comprises a 472.1-Mb nuclear genome together with representative nitroplast, chloroplast, and mitochondrial genomes of 1.49 Mb, 107 kb, and 44 kb, respectively. The four genomic compartments have strongly differentiated GC compositions, consistent with their distinct evolutionary origins. The large nuclear genome does not appear to reflect a corresponding expansion of protein-coding capacity. Repeat annotation indicates that approximately 77% of the nuclear assembly is repetitive, leaving approximately 108 Mb of nonrepetitive sequence containing roughly 16,000 predicted protein-coding genes. Phylogenomic analysis places B. bigelowii within the expected diversity of haptophytes, indicating that its unusual diazotrophic lifestyle is not associated with an anomalous phylogenetic position. Comparative analysis of nitrogen metabolism genes reveals extensive remodeling of host nitrogen acquisition and assimilation. B. bigelowii lacks major components required for nitrate and nitrite assimilation and has reduced capacity to use urea, cyanate, and several internally recycled nitrogen sources. In contrast, ammonium transport and the glutamine synthetase-glutamate synthase pathway are retained. This combination suggests reduced flexibility in nitrogen use and a host metabolism increasingly centered on ammonium supplied by the nitroplast. B. bigelowii also encodes an expanded set of flavodoxin and cryptochrome genes. Eleven of 14 flavodoxin candidates and 21 of 39 cryptochrome candidates contained motifs linked to nitroplast targeting. Together with previous evidence that some of these proteins are abundantly imported into the nitroplast, these expansions point to host-encoded roles in nitroplast redox metabolism and diel regulation. These genome resources establish a foundation for investigating nitroplast protein import, host-organelle metabolic integration, and the genomic consequences of acquiring an intracellular nitrogen-fixing compartment. They further show that the evolution of the B. bigelowii-UCYN-A relationship involved substantial remodeling of genome architecture and nitrogen metabolism in both partners.

genomics↗

Dissecting functional elements in giant genomes using the first generation of high quality salamander assemblies

Salamanders are an enduring and historically significant group that helped originate multiple scientific fields of study, including regeneration, cytogenetics, experimental embryology, cloning, evolutionary developmental biology and evolution of extreme genome size. We generated a high-quality, single haplotype assembly for the 32 Gb axolotl (Ambystoma mexicanum) genome using an F1 hybrid between axolotl and a divergent relative the tiger salamander (A. tigrinum). Using multi-genome alignments to other salamanders that meet VGP metrics, we leveraged strong conservation of karyotypic structure to identify >523,000 highly conserved non-coding elements within massively expanded intronic and intergenic regions, the vast majority of which are unique to the salamander lineage. Orthogonal measures of chromatin state and enhancer activity confirmed that many conserved elements correspond to cis-regulatory sequences and identified several thousand that are utilized during regeneration. The conserved elements identified here will enable robust functional genomic analyses of tissue regeneration and other traits that uniquely empower salamander models in biological research.

genomics↗

Genomic Correlates of APOBEC-Associated Mutagenesis in Esophageal Squamous Cell Carcinoma

Background and Aims: APOBEC-associated mutagenesis is prominent in esophageal squamous cell carcinoma (ESCC), but genomic features associated with its intertumoral variability remain incompletely characterized. We investigated genomic correlates of APOBEC-associated mutagenesis while accounting for the compositional structure of mutational signature data. Methods: Mutational signatures were analyzed in 552 ESCC tumors from eight countries. APOBEC-associated mutagenesis was quantified as SBS2 plus SBS13 using absolute mutation counts and proportional contributions. Associations with co-occurring mutational signatures, total SBS burden, recurrent driver-gene alterations, and country were evaluated using correlation, sensitivity, and multivariable analyses. Principal component and regression-model robustness were additionally assessed. Results: APOBEC burden varied markedly across tumors (median, 2,002 mutations; IQR, 987-4,346). Several associations observed using signature proportions were not maintained in absolute-count analyses: SBS1, SBS3, and SBS5 changed direction, indicating sensitivity to compositional representation. In contrast, SBS18 remained inversely associated with APOBEC-associated mutagenesis in all variable pairings examined: proportion versus proportion (Spearman rho = -0.527), APOBEC proportion versus SBS18 absolute count (r = -0.435), and absolute count versus absolute count (Pearson r = -0.319, P = 1.59 x 10^-14; Spearman rho = -0.317). These are distinct comparisons rather than discrepant estimates. Notably, this cohort-wide relationship was primarily characterized by higher APOBEC burden in SBS18-negative than SBS18-positive tumors rather than a continuous inverse relationship among SBS18-positive tumors. The multivariable model had an in-sample R^2 of 0.400 but lower and variable 10-fold cross-validated performance (mean R^2 = 0.273). Country added little explanatory information to this model (delta R^2 = 0.008; global P = 0.402). ZNF750-mutant tumors had higher APOBEC burden than wild-type tumors (BH-FDR q = 0.0032), although only 12 tumors carried ZNF750 alterations. Conclusion: Genomic correlates of APOBEC-associated mutagenesis in ESCC are sensitive to the representation of mutational signature activity. SBS18 showed the most consistent inverse association, whereas the ZNF750 association warrants independent validation.

genomics↗