Elimination of lipaemic interference by high-speed centrifugation

IntroductionIn order to deliver high quality results, detection and elimination of possible analytical interferences, such as lipaemia, is crucial. The aim of this study is to evaluate the efficacy of high-speed centrifugation in eliminating lipaemic interference and to define own lipaemic index (LI) for the studied biochemical analytes. Materials and methodsEvaluated analytes were: albumin, alkaline phosphatase, alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), calcium, creatinine, gamma-glutamyltransferase (GGT), glucose, phosphates, total proteins, urea and total bilirubin. Those analytes and LIs have been analysed in duplicate in the Roche Diagnostics-c8000 analyser in samples centrifuged at 3000 rpm/10 minutes in the SL16 (Thermo Scientific, Waltham, USA) centrifuge and according to an own high-speed centrifugation protocol (12,900 rpm/15 minutes) in the MicroCL17R (Thermo Scientific, Waltham, USA) centrifuge. Lipaemia has been measured in each sample. The efficiency of high-speed centrifugation is verified by the Wilcoxon test (P < 0.05). In cases where significant differences are observed, our own LI is calculated. For ALT and AST, it is verified by McNemar test (P < 0.05). For creatinine, both Wilcoxon and McNemar test were applied. ResultsThere were statistically significant differences in analyte concentration before and after high-speed centrifugation for: albumin, creatinine, GGT, glucose, phosphates, urea and total bilirrubin. Own LI is calculated. McNemar test shows statistically significant diferences in the proportion of delivered results before and after high-speed centrifugation in ALT, AST and creatinine. ConclusionsThis study confirms the efficacy of high-speed centrifugation protocol for all the considered analytes, excepting calcium, alkaline phosphatase and total proteins

High Performance of a Dominant/X-Linked Gene Panel in Patients with Neurodevelopmental Disorders

Neurodevelopmental disorders (NDDs) affect 2-5% of the population and approximately 50% of cases are due to genetic factors. Since de novo pathogenic variants account for the majority of cases, a gene panel including 460 dominant and X-linked genes was designed and applied to 398 patients affected by intellectual disability (ID)/global developmental delay (GDD) and/or autism (ASD). Pathogenic variants were identified in 83 different genes showing the high genetic heterogeneity of NDDs. A molecular diagnosis was established in 28.6% of patients after high-depth sequencing and stringent variant filtering. Compared to other available gene panel solutions for NDD molecular diagnosis, our panel has a higher diagnostic yield for both ID/GDD and ASD. As reported previously, a significantly higher diagnostic yield was observed: (i) in patients affected by ID/GDD compared to those affected only by ASD, and (ii) in females despite the higher proportion of males among our patients. No differences in diagnostic rates were found between patients affected by different levels of ID severity. Interestingly, patients harboring pathogenic variants presented different phenotypic features, suggesting that deep phenotypic profiling may help in predicting the presence of a pathogenic variant. Despite the high performance of our panel, whole exome-sequencing (WES) approaches may represent a more robust solution. For this reason, we propose the list of genes included in our customized gene panel and the variant filtering procedure presented here as a first-tier approach for the molecular diagnosis of NDDs in WES studies

Case report : Identification of a novel variant p.Gly215Arg in the CHN1 gene causing Moebius syndrome

Background: Moebius Syndrome (MBS) is a rare congenital neurological disorder characterized by paralysis of facial nerves, impairment of ocular abduction and other variable abnormalities. MBS has been attributed to both environmental and genetic factors as potential causes. Until now only two genes, PLXND1 and REV3L have been identified to cause MBS. Results: We present a 9-year-old male clinically diagnosed with MBS, presenting facial palsy, altered ocular mobility, microglossia, dental anomalies and congenital torticollis. Radiologically, he lacks both abducens nerves and shows altered symmetry of both facial and vestibulocochlear nerves. Whole-exome sequence identified a de novo missense variant c.643

SpadaHC: a database to improve the classification of variants in hereditary cancer genes in the Spanish population

Accurate classification of genetic variants is crucial for clinical decision-making in hereditary cancer. In Spain, genetic diagnostic laboratories have traditionally approached this task independently due to the lack of a dedicated resource. Here we present SpadaHC, a web-based database for sharing variants in hereditary cancer genes in the Spanish population. SpadaHC is implemented using a three-tier architecture consisting of a relational database, a web tool and a bioinformatics pipeline. Contributing laboratories can share variant classifications and variants from individuals in Variant Calling Format (VCF) format. The platform supports open and restricted access, flexible dataset submissions, automatic pseudo-anonymization, VCF quality control, variant normalization and liftover between genome builds. Users can flexibly explore and search data, receive automatic discrepancy notifications and access SpadaHC population frequencies based on many criteria. In February 2024, SpadaHC included 18 laboratory members, storing 1.17 million variants from 4306 patients and 16 343 laboratory classifications. In the first analysis of the shared data, we identified 84 genetic variants with clinically relevant discrepancies in their classifications and addressed them through a three-phase resolution strategy. This work highlights the importance of data sharing to promote consistency in variant classifications among laboratories, so patients and family members can benefit from more accurate clinical management.Database URL: https://spadahc.ciberisciii.es/ Overview of SpadaHC and its main views. (A) List of existing variants in SpadaHC (in the image, search for the ATM gene). The 'Expert Cl.' column shows the classification made by a group of experts; the 'Lab Cl.' column shows a summary of the classifications made by the laboratories. (B) Allele frequency of a variant in the SpadaHC population according to clinical suspicion and sex. (C) Classifications provided by the laboratories for a variant. (D) List of patients carrying a variant. (E) Histogram showing the coverage and frequency (allele balance) with which the variant was detected in carrier patients. Alt text: SpadaHC overview; laboratories can share datasets of variant classifications (Excel) and variants from individuals (VCFs + Excel). The datasets undergo quality control, bioinformatics pipeline annotation and database integration before being displayed in SpadaHC. The graphical abstract also shows five views of SpadaHC

Systematic Collaborative Reanalysis of Genomic Data Improves Diagnostic Yield in Neurologic Rare Diseases

Altres ajuts: Generalitat de Catalunya, Departament de Salut; Generalitat de Catalunya, Departament d'Empresa i Coneixement i CERCA Program; Ministerio de Ciencia e Innovación; Instituto Nacional de Bioinformática; ELIXIR Implementation Studies (CNAG-CRG); Centro de Investigaciones Biomédicas en Red de Enfermedades Raras; Centro de Excelencia Severo Ochoa; European Regional Development Fund (FEDER).Many patients experiencing a rare disease remain undiagnosed even after genomic testing. Reanalysis of existing genomic data has shown to increase diagnostic yield, although there are few systematic and comprehensive reanalysis efforts that enable collaborative interpretation and future reinterpretation. The Undiagnosed Rare Disease Program of Catalonia project collated previously inconclusive good quality genomic data (panels, exomes, and genomes) and standardized phenotypic profiles from 323 families (543 individuals) with a neurologic rare disease. The data were reanalyzed systematically to identify relatedness, runs of homozygosity, consanguinity, single-nucleotide variants, insertions and deletions, and copy number variants. Data were shared and collaboratively interpreted within the consortium through a customized Genome-Phenome Analysis Platform, which also enables future data reinterpretation. Reanalysis of existing genomic data provided a diagnosis for 20.7% of the patients, including 1.8% diagnosed after the generation of additional genomic data to identify a second pathogenic heterozygous variant. Diagnostic rate was significantly higher for family-based exome/genome reanalysis compared with singleton panels. Most new diagnoses were attributable to recent gene-disease associations (50.8%), additional or improved bioinformatic analysis (19.7%), and standardized phenotyping data integrated within the Undiagnosed Rare Disease Program of Catalonia Genome-Phenome Analysis Platform functionalities (18%)

Human genetic disorders: Mendelian and complex diseases

From Darwin’s “On the Origin of Species”, many years elapsed before human diseases were considered in an evolutionary framework. Besides theoretical and empirical advances, we are far from the complete understanding of disease aetiology. Highly penetrant disorders with Mendelian inheritance are mostly explained by the mutation-selection balance model, which is insufficient to describe the selective pressures acting on the full set of alleles related to diseases. We show in the first two papers that Next Generation Sequencing (NGS) technologies provide a unique opportunity to investigate variation and contribute to the understanding of the genetic architecture of disease. Besides exploring the role of rare and copy number variants in Parkinson’s disease (PD), we demonstrate the functional relation between Mendelian and idiopathic PD. In the last paper, we report that variation in genes previously related to Mendelian disorders has a more important role in driving complex disease susceptibility than genes associated only to complex diseases.Des de l'Origen de les Espècies de Darwin van passar molts anys abans que les malalties humanes fossin considerades sota un marc evolutiu. Tanmateix, tot i els darrers avenços teòrics i empírics, estem molt lluny de tenir una comprensió completa de l'etiologia de les malalties humanes. Mentre els trastorns altament penetrants amb herència mendeliana poden explicar-se sota un model d’equilibri mutació-selecció, aquest és insuficient per descriure les pressions selectives que actuen sobre tot el conjunt d'al·lels associats a malalties. Mostrem en els dos primers treballs que les noves tecnologies de seqüenciació proporcionen una oportunitat única per investigar la variació i contribuir a la comprensió de l'arquitectura genètica de la malaltia. A més d'explorar el paper de les variants rares i en el nombre de còpies en la malaltia de Parkinson (PD), demostrem la relació funcional entre les formes mendelianes i idiopàtiques d’aquesta malaltia. En el darrer treball, mostrem sota una perspectiva evolutiva i funcional que, en comparació amb la variació genètica en gens associats només a malalties complexes, la variació en gens prèviament relacionats amb trastorns Mendelians sembla tenir un paper clarament més important en la susceptibilitat a la malaltia complexa

Human genetic disorders: Mendelian and complex diseases

From Darwin’s “On the Origin of Species”, many years elapsed before human diseases were considered in an evolutionary framework. Besides theoretical and empirical advances, we are far from the complete understanding of disease aetiology. Highly penetrant disorders with Mendelian inheritance are mostly explained by the mutation-selection balance model, which is insufficient to describe the selective pressures acting on the full set of alleles related to diseases. We show in the first two papers that Next Generation Sequencing (NGS) technologies provide a unique opportunity to investigate variation and contribute to the understanding of the genetic architecture of disease. Besides exploring the role of rare and copy number variants in Parkinson’s disease (PD), we demonstrate the functional relation between Mendelian and idiopathic PD. In the last paper, we report that variation in genes previously related to Mendelian disorders has a more important role in driving complex disease susceptibility than genes associated only to complex diseases.Des de l'Origen de les Espècies de Darwin van passar molts anys abans que les malalties humanes fossin considerades sota un marc evolutiu. Tanmateix, tot i els darrers avenços teòrics i empírics, estem molt lluny de tenir una comprensió completa de l'etiologia de les malalties humanes. Mentre els trastorns altament penetrants amb herència mendeliana poden explicar-se sota un model d’equilibri mutació-selecció, aquest és insuficient per descriure les pressions selectives que actuen sobre tot el conjunt d'al·lels associats a malalties. Mostrem en els dos primers treballs que les noves tecnologies de seqüenciació proporcionen una oportunitat única per investigar la variació i contribuir a la comprensió de l'arquitectura genètica de la malaltia. A més d'explorar el paper de les variants rares i en el nombre de còpies en la malaltia de Parkinson (PD), demostrem la relació funcional entre les formes mendelianes i idiopàtiques d’aquesta malaltia. En el darrer treball, mostrem sota una perspectiva evolutiva i funcional que, en comparació amb la variació genètica en gens associats només a malalties complexes, la variació en gens prèviament relacionats amb trastorns Mendelians sembla tenir un paper clarament més important en la susceptibilitat a la malaltia complexa

Disease genes and evolution: a complex issue

Trabajo presentado en la 4th Meeting of the Spanish Society of the Evolutionary Biology (SESBE 2013) celebrada en Barcelona del 27 al 29 de noviembre de 2013.N

Genome-phenome explorer (GePhEx): a tool for the visualization and interpretation of phenotypic relationships supported by genetic evidence

[Motivation] Association studies based on SNP arrays and Next Generation Sequencing technologies have enabled the discovery of thousands of genetic loci related to human diseases. Nevertheless, their biological interpretation is still elusive, and their medical applications limited. Recently, various tools have been developed to help bridging the gap between genomes and phenomes. To our knowledge, however none of these tools allows users to retrieve the phenotype-wide list of genetic variants that may be linked to a given disease or to visually explore the joint genetic architecture of different pathologies.[Results] We present the Genome-Phenome Explorer (GePhEx), a web-tool easing the visual exploration of phenotypic relationships supported by genetic evidences. GePhEx is primarily based on the thorough analysis of linkage disequilibrium between disease-associated variants and also considers relationships based on genes, pathways or drug-targets, leveraging on publicly available variant-disease associations to detect potential relationships between diseases. We demonstrate that GePhEx does retrieve well-known relationships as well as novel ones, and that, thus, it might help shedding light on the patho-physiological mechanisms underlying complex diseases. To this end, we investigate the potential relationship between schizophrenia and lung cancer, first detected using GePhEx and provide further evidence supporting a functional link between them.This work was supported by Ministerio de Economía y Competitividad (MINECO): BFU2015-68649-P (MINECO/FEDER, UE), and by the Agencia Estatal de investigación: AEI-PGC2018-101927-B-I00 (FEDER/UE), by Direcció General de Recerca, Generalitat de Catalunya (2017SGR880) and by the Spanish National Institute of Bioinformatics (PT17/0009/0020), the REEM (RD16/00150017) of the Instituto de Salud Carlos III. This research has also received funding from the European Union's Horizon 2020 research and innovation programme 2014–2020 under Grant Agreement N°. 634143 (MedBioinformatics).Peer reviewe

Properties of human disease genes and the role of genes linked to Mendelian disorders in complex disease aetiology

Do genes presenting variation that has been linked to human disease have different biological properties than genes that have never been related to disease? What is the relationship between disease and fitness? Are the evolutionary pressures that affect genes linked to Mendelian diseases the same to those acting on genes whose variation contributes to complex disorders? The answers to these questions could shed light on the architecture of human genetic disorders and may have relevant implications when designing mapping strategies in future genetic studies. Here we show that, relative to non-disease genes, human disease (HD) genes have specific evolutionary profiles and protein network properties. Additionally, our results indicate that the mutation-selection balance renders an insufficient account of the evolutionary history of some HD genes and that adaptive selection could also contribute to shape their genetic architecture. Notably, several biological features of HD genes depend on the type of pathology (complex or Mendelian) with which they are related. For example, genes harbouring both causal variants for Mendelian disorders and risk factors for complex disease traits (Complex-Mendelian genes), tend to present higher functional relevance in the protein network and higher expression levels than genes associated only with complex disorders. Moreover, risk variants in Complex-Mendelian genes tend to present higher odds ratios than those on genes associated with the same complex disorders but with no link to Mendelian diseases. Taken together, our results suggest that genetic variation at genes linked to Mendelian disorders plays an important role in driving susceptibility to complex disease.This work was supported by Ministerio de Ciencia e Innovación, Spain (SAF2011-29239 to EB and BFU2012-38236 to AN), by Direcció General de Recerca, Generalitat de Catalunya (2014SGR1311 and 2014SGR866), by the Spanish National Institute of Bioinfomatics of the Instituto de Salud Carlos III (PT13/0001/0026) and by FEDER (Fondo Europeo de Desarrollo Regional)/FSE (Fondo Social Europeo). Funding to pay the Open Access publication charges for this article was provided by the ICREA Award granted to EB by the Institució Catalana de Recerca i Estudis Avançats (Generalitat de Catalunya)