Cover: In Smith and Sheffield (http://doi.org/10.1002/cphg.101), the image shows ATAC-seq general workflow. Raw reads are processed through a series of steps to produce uniform intermediate results, which can then be further analyzed with more specific analyses relevant to a biological research question.

Clinical interpretation of DNA sequence variants is a critical step in reporting clinical genetic testing results. Application of next-generation sequencing technology in molecular genetic testing has facilitated diagnoses of genetic disorders in clinical practice. However, the large number of DNA sequence variants detected in clinical specimens, many of which have never been seen before, make clinical interpretation challenging. Recommendations by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) have been widely adopted by clinical laboratories around the world to guide clinical interpretation of sequence variants. The ClinGen Sequence Variant Interpretation Working Group and various disease-specific variant curation expert panels have also developed specifications for the ACMG/AMP recommendations. Despite these efforts to standardize variant interpretation in clinical practice, different laboratories may subjectively use professional judgment to determine which criteria are applicable when classifying a variant. In addition, clinicians and researchers who are not familiar with the variant interpretation process may have difficulty understanding clinical genetic reports and communicating the clinical significance of genetic testing results. Here we provide a step-by-step protocol for clinical interpretation of sequence variants, including practical examples. By following this protocol, clinical laboratory geneticists can interpret the clinical significance of sequence variants according to the ACMG/AMP recommendations and ClinGen framework. Furthermore, this article will help clinicians and researchers to understand variant classification in clinical genetic testing reports and evaluate the quality of the reports. © 2020 by John Wiley & Sons, Inc. Basic Protocol: Interpreting the clinical significance of sequence variants Support Protocol: Reevaluating the clinical significance of sequence variants.

After now more than 170years of research the dynamic three-dimensional chromatin architecture of genomes and the co-evolved interaction networks of regulatory elements which create genome function - i.e. the storage, expression, and finally replication of genetic information - involves ever more investigative efforts in respect to not only the pure understanding of living organisms, but also diagnosis, treatment, and even future genome engineering. To study genomic interactions, we developed a novel and superior high-quality selective high-resolution, high-throughput chromosome interaction capture method - T2C (targeted chromatin capture) - which allows to arbitrarily balance resolution, frequency range of interactions, and the investigated general genetic region or single interactions in a highly cost-effective manner in respect to the obtainable result and compared to other techniques. Beyond, T2C has such a high signal-to-noise ratio at high resolution that the "genomic" statistical mechanics level can be reached. With the guided T2C protocol described here, we were already able to finally determine the chromatin quasi-fiber conformation and its folding into stable multi-loop aggregates/rosettes connected by a linker. Actually, this guided T2C protocol provides the means for architectural genome sequencing from the level of the single base pair to the entire cell nucleus and thus to analyze genetic interactions in respect to genome function in a systems biological manner in general as well as in settings ranging from basic research, via diagnostics and treatment, to genome engineering. © 2018 by John Wiley & Sons, Inc.

Insulin-expressing beta cells are crucial for the maintenance of systemic glucose homeostasis. Elucidation of the molecular and cellular mechanisms of beta cell development, expansion, survival, and function are required for full understanding of the molecular pathogenesis of diabetes. However, access to human beta cells for such studies is limited by virtue of the logistics of acquisition, prior medical status of donor, and imperfect culture systems for maintaining beta cell identity and function after isolation from human pancreas. Here, a technique for generation of beta cells from human pluripotent stem cells (hPSCs) by modification of key signaling pathways during islet development is described. Up to 70% C-peptide-positive beta cells can be obtained from endodermal anlagen after 27 days of differentiation with specific growth factors and small molecules. Although 50% of them are monohormonal C-peptide-positive cells and have molecular and cellular characteristics consistent with human beta cells in the Islets of Langerhans, a sub-population co-expressing other endocrine markers are also generated, indicating the immaturity of these cells. © 2018 by John Wiley & Sons, Inc.

Identification of sequence variants that create or eliminate splice sites has proven to be a significant challenge and represents one of many roadblocks in the clinical interpretation of rare genetic variation. Current methods of identifying splice altering sequence variants exist, however, these are limited by an imperfect understanding of splice signals and cumbersome functional assays. We have recently developed a computational tool that prioritizes putative splice-altering sequence variants, and a moderate-throughput minigene assay that confirms the variants which alter splicing. This bioinformatic strategy represents a substantial increase in accuracy and efficiency of historical in vitro splicing assays. In this unit we give detailed instructions on how to organize, run, and interpret various features of this protocol. We expect that splice-altering variants revealed through this protocol can be reliably carried forward for further clinical and biological analyses.

Quantitative analysis of urine acylglycines has shown to be a highly sensitive and specific method with proven clinical utility for the diagnosis of several inherited metabolic disorders including: medium chain acyl-CoA dehydrogenase deficiency, multiple acyl-CoA dehydrogenase deficiency, short chain acyl-CoA dehydrogenase deficiency, 3-methylcrotonyl-CoA carboxylase deficiency, 2-methylbutyryl-CoA dehydrogenase deficiency, isovaleric acidemia, propionic academia, and isobutyryl-CoA dehydrogenase deficiency. Here, a method that is currently performed using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) is described. © 2016 by John Wiley & Sons, Inc.

Fabry disease is an X-linked lysosomal storage disorder caused by the absence or reduction of the enzyme α-galactosidase A activity. Currently, globotriaosylsphingosine (lyso-Gb3 ) and globotriaosylceramide (Gb3 ) are used as biomarkers to diagnose and monitor Fabry patients. However, recent metabolomic studies have shown that several glycosphingolipids are also elevated in biological fluids of affected patients and may be related to disease manifestations. This unit describes a multiplex methodology targeting the analysis of urinary lyso-Gb3 and seven structurally related analogs. A solid-phase extraction process is performed, then lyso-Gb3 and its analogs are analyzed simultaneously with an internal standard by ultra-performance liquid chromatography (UPLC) coupled to a tandem mass spectrometry (MS/MS) system. This methodology can be useful for the diagnosis of Fabry patients, including patients with cardiac variant mutations, but also to monitor the efficacy of therapeutic interventions, considering that lyso-Gb3 analogs are more elevated than lyso-Gb3 itself in urine. © 2016 by John Wiley & Sons, Inc.

This unit describes the concepts and practical techniques for annotating genomic variants in the human genome to estimate their functional significance. With the rapid increase of available whole exome and whole genome sequencing information for human studies, annotation techniques have become progressively more important for highlighting and prioritizing nucleotide variants and their potential impact on genes and other genetic constructs. Here, we present an overview of different types of variant annotation approaches and elaborate on their foundations, assumptions, and the downstream consequences of their use. Computational approaches and tools to assign annotations and to identify variants are reviewed. Further, the general philosophy of assigning potential function to a genetic change within the biological context of a disease is discussed.