Umair et al 2018 Clinical Genetics (original) (raw)

Comprehensive genotyping for 18 blood group systems using a multiplex ligation-dependent probe amplification assay shows a high degree of accuracy

Transfusion, 2013

Background: In recent years genotyping methods have been implemented in blood banks as alternative to comprehensive serologic typing. We evaluated a newly developed assay for convenient and comprehensive genotyping of blood group alleles based on multiplex ligation-dependent probe amplification [MLPA] technology. Methods: We analyzed 103 random and 150 selected samples to validate the specificity of the blood-MLPA assay that is able to determine the presence, absence, and copy number of 48 blood group and 112 variant alleles of 18 blood group systems. A total of 4038 serologic typing results, including results of 52 different antigens, were available for these samples. Results: In 4018 (99.5%) of the 4038 serologic typing results the predicted phenotypes by the blood-MLPA were in concordance with serologic typing. Twenty discordant results were due to false-positive serologic results (n = 2), false-negative serologic results (n = 1), inability of routine serologic typing to detect variant antigens (n = 14), or false-positive prediction from the blood-MLPA due to the presence of a null allele (n = 3). Conclusion: The blood-MLPA reliably predicts the presence or absence of blood group antigens, including almost all clinically relevant blood group antigens, except ABO, in patients and donors. Furthermore, it is the first assay that determines copy numbers of blood group alleles in the same test. It even provides more detailed and accurate information than serologic typing, because most variant alleles are immediately recognized. Because only standard laboratory equipment is needed, this assay finally offers the possibility to comprehensively type recipients and makes extensive matching for selected patients groups more feasible.

Identification of Novel Genetic Variants in CVID Patients With Autoimmunity, Autoinflammation, or Malignancy

Frontiers in Immunology, 2020

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by recurrent bacterial infections and defined by reduced levels of IgG, IgA, and/or IgM, insufficient response to polysaccharide vaccination, and an abnormal B-cell immunophenotype with a significantly reduced fraction of isotype-switched memory B cells. In addition to this infectious phenotype, at least one third of the patients experience autoimmune, autoinflammatory, granulomatous, and/or malignant complications. The very heterogeneous presentation strongly suggests a collection of different disease entities with somewhat different pathogeneses and most likely diverse genetic etiologies. Major progress has been made during recent years with the advent and introduction of next-generation sequencing, initially for research purposes, but more recently in clinical practice. In the present study, we performed whole exome sequencing on 20 CVID patients with autoimmunity, autoinflammation, and/or malignancy from the Danish CVID cohort with the aim to identify gene variants with a certain, possible, or potential disease-causing role in CVID. Through bioinformatics analyses, we identified variants with possible/probable disease-causing potential in nine of the patients. Of these, three patients had four variants in three different genes classified as likely pathogenic (NFKB1, TNFAIP3, and TTC37), whereas in six patients, we identified seven variants of possible pathogenic potential classified as variants of unknown significance (STAT3, IL17F, IRAK4, DDX41, NLRC3, TNFRSF1A, and PLCG2). In the remaining 11 patients, we did not identify possible genetic causes. Genetic findings were correlated to clinical disease presentation, clinical immunological phenotype, and disease complications. We suggest that the variants identified in the present work should lay the ground for future studies to functionally validate their disease-causing potential and to investigate at the mechanistic and molecular level their precise role in CVID pathogenesis. Overall, we believe that the present work contributes important new insights into the genetic basis of CVID and particular in the subset of CVID patients with a complex phenotype involving not only infection, but also autoimmunity, autoinflammation, and malignancy.

Professional responsibilities regarding the provision, publication, and dissemination of patient phenotypes in the context of clinical genetic and genomic testing: points to consider-a statement of the American College of Medical Genetics and Genomics (ACMG)

Genetics in medicine : official journal of the American College of Medical Genetics, 2018

Disclaimer: This Points to Consider document is designed as an educational resource to provide best practices for medical genetic clinicians, laboratories, and journals regarding the provision, publication, and dissemination of patient phenotypes in the context of genomic testing, clinical genetic practice, and research. While the goal of the document is the improvement of patient care, the considerations and practices described should not be considered inclusive of all proper considerations and practices or exclusive of others that are reasonably directed to obtaining the same goal. In determining the value of any practice, clinicians, laboratories, and journals should apply their own professional standards and judgment to the specific circumstances presented.The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the authors' affiliated institutions.GENETICS in MEDICINE advance online publication, 11 Janu...

Current Genetic Defects in Common Variable Immune Deficiency Patients on the Geography Between Europe and Asia

Research Square (Research Square), 2023

Identi cation of the causes of monogenetic common variable immune de ciency (CVID) patients has rapidly increased in the last years by means of worldwide availability of appropriate genetic diagnostic methods. However, up to date, very limited numbers of reports demostrating the role of geography, ethnicity and consanguinity have been published. Here, we reported the rst study of Turkish CVID patients and compared them with the results of three countries from America, Europe and Asia. A total of 100 children diagnosed as CVID according to the criteria of European Society for Immunode ciencies were enrolled and they were genetically analyzed by using Targeted Next Generation Sequencing and Whole Exome Sequencing. The median age of our patients was 5.8 years (range, 3.0-16.0 years) at clinical diagnosis and 9.0 years (range, 4.8-21.0 years) at the time of genetic diagnosis. The consanguianity rate was 24%. Disease-causing pathogenic mutations were de ned in 40% of patients in a total of 17 different genes. Sixteen of 40 identi ed mutations were novel (40%). We determined 18 surface molecular defects, 10 cytosolic defects, 9 nuclear defects and 3 others. In our cohort, the most common gene was TACI (15/40 in mutation identi ed cases and 15/100 in all cases) followed by the others such as PLCÒ¯2, LRBA, TCF3 and STAT1. In contrast to our expectations, our results were more similar to American and European population rather than Asians, although we also have high consanguinity rates and live on the geography between Europe and Asia. Genetic investigation is a great challenge, because of the complexity and heterogenity of the disease and each country has to know their own current genetic landscape in CVID for a better and successful management of the patients.

Molecular genetic testing methodologies in hematopoietic diseases: current and future methods

International Journal of Laboratory Hematology

Introduction: Rapid technological advancements in clinical molecular genetics have increased our diagnostic and prognostic capabilities in health care. Understanding these assays, as well as how they may change over time, is critical for pathologists, clinicians, and translational researchers alike. Methods: This review provides a practical summary and basic reference for current molecular genetic technologies, as well as new testing methodologies that are in use, gaining momentum, or anticipated to contribute more broadly in the future. Results: Here, we discuss DNA and RNA based methodologies including classic assays such as the polymerase chain reaction (PCR), Sanger sequencing, and microarrays, to more cutting-edge next-generation sequencing (NGS) based assays and emerging molecular technologies such as cell-free DNA (cfDNA) or circulating tumor DNA (ctDNA), and NGS-based detection of infectious disease organisms. Conclusion: This review serves as a basic foundation for knowledge in current and emerging clinical molecular genetic technologies.

Systematic identification of genetic systems associated with phenotypes in patients with rare genomic copy number variations

Human Genetics, 2020

Copy number variation (CNV) related disorders tend to show complex phenotypic profiles that do not match known diseases. This makes it difficult to ascertain their underlying molecular basis. A potential solution is to compare the affected genomic regions for multiple patients that share a pathological phenotype, looking for commonalities. Here, we present a novel approach to associate phenotypes with functional systems, in terms of GO categories and KEGG and Reactome pathways, based on patient data. The approach uses genomic and phenomic data from the same patients, finding shared genomic regions between patients with similar phenotypes. These regions are mapped to genes to find associated functional systems. We applied the approach to analyse patients in the DECIPHER database with de novo CNVs, finding functional systems associated with most phenotypes, often due to mutations affecting related genes in the same genomic region. Manual inspection of the ten top-scoring phenotypes found multiple FunSys connections supported by the previous studies for seven of them. The workflow also produces reports focussed on the genes and FunSys connected to the different phenotypes, alongside patientspecific reports, which give details of the associated genes and FunSys for each individual in the cohort. These can be run in "confidential" mode, preserving patient confidentiality. The workflow presented here can be used to associate phenotypes with functional systems using data at the level of a whole cohort of patients, identifying important connections that could not be found when considering them individually. The full workflow is available for download, enabling it to be run on any patient cohort for which phenotypic and CNV data are available.