Genome Mapping Nomenclature.

Background Genome Mapping Technologies (optical and electronic) uses ultra high-molecular weight DNA to detect structural variation and has an application in constitutional genetic disorders, haematological neoplasms and solid tumours. Genome mapping can detect balanced and unbalanced structural variation, copy number changes and haplotypes. The technique is analogous to chromosomal microarray analysis although genome mapping has the added benefit of being able to detect and ascertain the nature of more abnormalities than array, karyotyping or FISH. Key Messages This paper describes a specific nomenclature for genome mapping that can be used by diagnostic and research centres to accurately report their findings. An international nomenclature is essential for patient results to be understood by different healthcare providers as well as clear communication in publications and consistency in databases. Summary Genome mapping can detect aneuploidy, balanced and unbalanced structural variation as well as copy number changes. The Standing Committee for the International System for Human Cytogenomic Nomenclature (ISCN), recognised there was a need for a specific nomenclature for genome mapping that encompasses the range of abnormalities detected by this technique. This paper explains the general principles of the nomenclature as well as giving specific ISCN examples for the different types of numerical and structural rearrangements.

Addenda to ISCN 2020.

Since the publication of ISCN 2020, the ISCN Standing Committee have noted some clarification of the text and additional examples were needed. These addenda have already been published online (https://iscn.karger.com/) and this short report summarises the ISCN 2020 addenda for the benefit of participants. These addenda will be included in the release of the next version of ISCN.

The International Collaboration for Cancer Classification and Research.

Gaps in the translation of research findings to clinical management have been recognized for decades. They exist for the diagnosis as well as the management of cancer. The international standards for cancer diagnosis are contained within the World Health Organization (WHO) Classification of Tumours, published by the International Agency for Research on Cancer (IARC) and known worldwide as the WHO Blue Books. In addition to their relevance to individual patients, these volumes provide a valuable contribution to cancer research and surveillance, fulfilling an important role in scientific evidence synthesis and international standard setting. However, the multidimensional nature of cancer classification, the way in which the WHO Classification of Tumours is constructed, and the scientific information overload in the field pose important challenges for the translation of research findings to tumour classification and hence cancer diagnosis. To help address these challenges, we have established the International Collaboration for Cancer Classification and Research (IC3 R) to provide a forum for the coordination of efforts in evidence generation, standard setting and best practice recommendations in the field of tumour classification. The first IC3 R meeting, held in Lyon, France, in February 2019, gathered representatives of major institutions involved in tumour classification and related fields to identify and discuss translational challenges in data comparability, standard setting, quality management, evidence evaluation and copyright, as well as to develop a collaborative plan for addressing these challenges.

Opportunistic genomic screening. Recommendations of the European Society of Human Genetics.

If genome sequencing is performed in health care, in theory the opportunity arises to take a further look at the data: opportunistic genomic screening (OGS). The European Society of Human Genetics (ESHG) in 2013 recommended that genome analysis should be restricted to the original health problem at least for the time being. Other organizations have argued that 'actionable' genetic variants should or could be reported (including American College of Medical Genetics and Genomics, French Society of Predictive and Personalized Medicine, Genomics England). They argue that the opportunity should be used to routinely and systematically look for secondary findings-so-called opportunistic screening. From a normative perspective, the distinguishing characteristic of screening is not so much its context (whether public health or health care), but the lack of an indication for having this specific test or investigation in those to whom screening is offered. Screening entails a more precarious benefits-to-risks balance. The ESHG continues to recommend a cautious approach to opportunistic screening. Proportionality and autonomy must be guaranteed, and in collectively funded health-care systems the potential benefits must be balanced against health care expenditures. With regard to genome sequencing in pediatrics, ESHG argues that it is premature to look for later-onset conditions in children. Counseling should be offered and informed consent is and should be a central ethical norm. Depending on developing evidence on penetrance, actionability, and available resources, OGS pilots may be justified to generate data for a future, informed, comparative analysis of OGS and its main alternatives, such as cascade testing.

Ensuring high standards for the delivery of NIPT world-wide: Development of an international external quality assessment scheme.

OBJECTIVE: To ensure accurate and appropriate reporting of non-invasive prenatal testing (NIPT) results, the standard of testing should be measured and monitored by participation in external quality assessment (EQA) schemes. The findings from international pilot EQAs for NIPT for the common trisomies are presented. METHODS: In the first pilot, three EQA providers used artificially manufactured reference materials to deliver an EQA for NIPT. The second pilot used clinically collected maternal plasma samples. The testing and reporting for aneuploidy status was performed by participating laboratories using routine procedures. Reports were assessed against peer ratified criteria and EQA scores were returned to participants. RESULTS: Forty laboratories participated in the first. Genotyping accuracy was high; four laboratories reported a critical genotyping error (10%) and two reported partial results. Eighty seven laboratories participated in the second pilot using maternal plasma, two reporting a critical genotyping error (2.3%). For both rounds, report content was variable with key information frequently omitted or difficult to identify within the report. CONCLUSIONS: We have successfully delivered an international pilot EQA for NIPT. When compared with currently available manufactured materials, EQA for NIPT was best performed using clinically collected maternal plasma. Work is required to define and improve the standard of reporting.

European guidelines for constitutional cytogenomic analysis.

With advancing technology and the consequent shift towards an increasing application of molecular genetic techniques (e.g., microarrays, next-generation sequencing) with the potential for higher resolution in specific contexts, as well as the application of combined testing strategies for the diagnosis of chromosomal disorders, it is crucial that cytogenetic/cytogenomic services keep up to date with technology and have documents that provide guidance in this constantly evolving scenario. These new guidelines therefore aim to provide an updated, practical and easily available document that will enable genetic laboratories to operate within acceptable standards and to maintain a quality service.

Recommended practice for laboratory reporting of non-invasive prenatal testing of trisomies 13, 18 and 21: a consensus opinion.

OBJECTIVE: Non-invasive prenatal testing (NIPT) for trisomies 13, 18 and 21 is used worldwide. Laboratory reports should provide clear, concise results with test limitations indicated, yet no national or local guidelines are currently available. Here, we aim to present minimum best practice guidelines. METHODS: All laboratories registered in the three European quality assurance schemes for molecular and cytogenetics were invited to complete an online survey focused on services provided for NIPT and non-invasive prenatal diagnosis. Laboratories delivering NIPT for aneuploidy were asked to submit two example reports; one high and one low risk result. Reports were reviewed for content and discussed at a meeting of laboratory providers and clinicians held at the ISPD 2016 conference in Berlin. RESULTS: Of the 122 laboratories that responded, 50 issued reports for NIPT and 43 of these submitted sample reports. Responses and reports were discussed by 72 attendees at the meeting. Consensus opinion was determined in several areas and used to develop best practice guidelines for reporting of NIPT results. CONCLUSIONS: Across Europe, there is considerable variation in reporting NIPT results. Here, we describe minimum best practice guidelines, which will be distributed to European laboratories, and reports audited in subsequent external quality assurance cycles. © 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

Guidelines for genomic array analysis in acquired haematological neoplastic disorders.

Genetic profiling is important for disease evaluation and prediction of prognosis or responsiveness to therapy in neoplasia. Microarray technologies, including array comparative genomic hybridization and single-nucleotide polymorphism-detecting arrays, have in recent years been introduced into the diagnostic setting for specific types of haematological malignancies and solid tumours. It can be used as a complementary test or depending on the neoplasia investigated, also as a standalone test. However, comprehensive and readable presentation of frequently identified complex genomic profiles remains challenging. To assist diagnostic laboratories, standardization and minimum criteria for clinical interpretation and reporting of acquired genomic abnormalities detected through arrays in neoplastic disorders are presented.

Towards a European consensus for reporting incidental findings during clinical NGS testing.

In 2013, the American College of Medical Genetics (ACMG) examined the issue of incidental findings in whole exome and whole genome sequencing, and introduced recommendations to search for, evaluate and report medically actionable variants in a set of 56 genes. At a debate held during the 2014 European Society for Human Genetics Conference (ESHG) in Milan, Italy, the first author of that paper presented this view in a debate session that did not end with a conclusive vote from the mainly European audience for or against reporting back actionable incidental findings. In this meeting report, we elaborate on the discussions held during a special meeting hosted at the ESHG in 2013 from posing the question 'How to reach a (European) consensus on reporting incidental findings and unclassified variants in diagnostic next generation sequencing'. We ask whether an European consensus exists on the reporting of incidental findings in genome diagnostics, and present a series of key issues that require discussion at both a national and European level in order to develop recommendations for handling incidental findings and unclassified variants in line with the legal and cultural particularities of individual European member states.

Recommendations for reporting results of diagnostic genetic testing (biochemical, cytogenetic and molecular genetic).

Genetic test results can have considerable importance for patients, their parents and more remote family members. Clinical therapy and surveillance, reproductive decisions and genetic diagnostics in family members, including prenatal diagnosis, are based on these results. The genetic test report should therefore provide a clear, concise, accurate, fully interpretative and authoritative answer to the clinical question. The need for harmonizing reporting practice of genetic tests has been recognised by the External Quality Assessment (EQA), providers and laboratories. The ESHG Genetic Services Quality Committee has produced reporting guidelines for the genetic disciplines (biochemical, cytogenetic and molecular genetic). These guidelines give assistance on report content, including the interpretation of results. Selected examples of genetic test reports for all three disciplines are provided in an annexe.

The introduction of arrays in prenatal diagnosis: a special challenge.

Genome-wide arrays are rapidly replacing conventional karyotyping in postnatal cytogenetic diagnostics and there is a growing request for arrays in the prenatal setting. Several studies have documented 1-3% additional abnormal findings in prenatal diagnosis with arrays compared to conventional karyotyping. A recent meta-analysis demonstrated that 5.2% extra diagnoses can be expected in fetuses with ultrasound abnormalities. However, no consensus exists as to whether the use of genome-wide arrays should be restricted to pregnancies with ultrasound abnormalities, performed in all women undergoing invasive prenatal testing or offered to all pregnant women. Moreover, the interpretation of array results in the prenatal situation is challenging due to the large numbers of copy number variants with no major phenotypic effect. This also raises the question of what, or what not to report, for example, how to deal with unsolicited findings. These issues were discussed at a working group meeting that preceded the European Society of Human Genetics 2011 Conference in Amsterdam. This article is the result of this meeting and explores the introduction of genome-wide arrays into routine prenatal diagnosis. We aim to give some general recommendations on how to develop practical guidelines that can be implemented in the local setting and that are consistent with the emerging international consensus.

The changing landscape of genetic testing and its impact on clinical and laboratory services and research in Europe.

The arrival of new genetic technologies that allow efficient examination of the whole human genome (microarray, next-generation sequencing) will impact upon both laboratories (cytogenetic and molecular genetics in the first instance) and clinical/medical genetic services. The interpretation of analytical results in terms of their clinical relevance and the predicted health status poses a challenge to both laboratory and clinical geneticists, due to the wealth and complexity of the information obtained. There is a need to discuss how to best restructure the genetic services logistically and to determine the clinical utility of genetic testing so that patients can receive appropriate advice and genetic testing. To weigh up the questions and challenges of the new genetic technologies, the European Society of Human Genetics (ESHG) held a series of workshops on 10 June 2010 in Gothenburg. This was part of an ESHG satellite symposium on the 'Changing landscape of genetic testing', co-organized by the ESHG Genetic Services Quality and Public and Professional Policy Committees. The audience consisted of a mix of geneticists, ethicists, social scientists and lawyers. In this paper, we summarize the discussions during the workshops and present some of the identified ways forward to improve and adapt the genetic services so that patients receive accurate and relevant information. This paper covers ethics, clinical utility, primary care, genetic services and the blurring boundaries between healthcare and research.

Diagnostic interpretation of array data using public databases and internet sources.

The range of commercially available array platforms and analysis software packages is expanding and their utility is improving, making reliable detection of copy-number variants (CNVs) relatively straightforward. Reliable interpretation of CNV data, however, is often difficult and requires expertise. With our knowledge of the human genome growing rapidly, applications for array testing continuously broadening, and the resolution of CNV detection increasing, this leads to great complexity in interpreting what can be daunting data. Correct CNV interpretation and optimal use of the genotype information provided by single-nucleotide polymorphism probes on an array depends largely on knowledge present in various resources. In addition to the availability of host laboratories' own datasets and national registries, there are several public databases and Internet resources with genotype and phenotype information that can be used for array data interpretation. With so many resources now available, it is important to know which are fit-for-purpose in a diagnostic setting. We summarize the characteristics of the most commonly used Internet databases and resources, and propose a general data interpretation strategy that can be used for comparative hybridization, comparative intensity, and genotype-based array data.

Quality control in FISH as part of a laboratory's quality management system.

Quality control in the laboratory setting requires the establishment of a quality management system (QMS) that covers training, standard operating procedures, internal quality control, validation of tests, and external quality assessment (EQA). Laboratory accreditation through inspection by an external body is also desirable as this provides an effective procedure for assuring quality and also reassures the patient that the laboratory is working to acceptable international standards. The implementation of fluorescence in situ hybridisation (FISH) in the routine diagnostic laboratory requires rigorous quality control with attention to when it is appropriate to apply the technology, a systematic approach to the validation of probes, policies and procedures documenting the analytical validity of all FISH tests performed, technical procedures involved, and a comprehensive means of reporting results. Knowledge of the limitations of any FISH test is required in relation to the probe and/or tissue being examined, since errors of analysis and interpretation can result in incorrect patient management. A structured QMS with internal quality control and regular audits will minimise the error rate.

The importance and value of EQA for diagnostic genetic laboratories.

Quality control in a laboratory setting requires the establishment of effective training, standard operating procedures, internal quality control, validation of tests and external quality assessment (EQA). A structured quality management system subject to regular internal and external audits will minimise the error rate. EQA, therefore, gives assurance, both to patients and referring clinicians, that the diagnostic laboratory is competent to produce results that are reliable and accurate. EQA is educational and aims to improve and validate the overall quality of genetic service to the user. Regular EQA assessment compares laboratory performance against set standards and also allows comparison between laboratories. Sometimes EQA can also help to define good standards (best practice), although this does depend on the type of EQA test. EQA interprets best practice standards (=quality) into a numerical score (=quantity). While international bodies or professional organisations set these standards, EQA is able to assess whether these standards are met, with any omissions resulting in a reduction in the total score. Although EQA has an educational role rather than a punitive role, critical errors affecting clinical management will result in a laboratory receiving a poor performance categorisation. Accurate analysis and interpretation are essential quality parameters that require extensive knowledge of the aetiology of genetic abnormalities/disease and risk factors. Training of staff in interpretation of the results together with a comprehensive means of reporting normal and abnormal genetic results underpins the diagnostic service to the patient. Poor-performing laboratories are, therefore, encouraged to review their internal processes. EQA schemes that have been established for many years have seen improvements in the analytical and reporting content over time, thereby improving the quality of diagnostic service available to patients.