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Expanded carrier screening (ECS) is used to identify individuals and couples at risk for having children with recessive or X-linked genetic conditions; however, personal health risks (PHR) can also be identified through this testing. There is limited data on how genetic counseling regarding PHR from ECS is perceived by the individual, or how they use this information. This study quantitatively surveyed individuals identified with these risks between September 2013 and March 2020. The 30-item survey included the validated Genomics Outcome Scale Short Form, the validated Genetic Counseling Satisfaction Scale, and original questions. Survey topics included pre-test knowledge of the possibility of discovering PHR through testing, satisfaction with pre-test education that addresses potential risks, perceived severity of PHR, empowerment by and understanding of information, anxiety levels related to their PHR, perceived genetic counseling support, and satisfaction with telehealth. A total of 416 completed surveys were analyzed using descriptive statistics, and linear and logistic regressions. The majority of participants were satisfied or extremely satisfied with pre-test education (n = 328; 78.8%) and telehealth (n = 329; 79.1%). However, more participants who were aware of the possibility of identifying PHR through ECS prior to testing were satisfied with pre-test education compared to those who were not aware. Additionally, a lack of prior awareness of PHR was associated with lower empowerment scores (p = .004). Those who were highly satisfied with genetic counseling were more likely to feel empowered and understand the information presented (p = .001). The majority of individuals used their PHR information following their results appointment (n = 391; 94.0%). The results of this study suggest that receiving PHR information was useful and was positively influenced by both pre-test education and the genetic counseling process.

An estimated 7% of the world's population are carriers for a hemoglobin disorder. Current guidelines recommend carrier screening by complete blood count, with follow-up hemoglobin electrophoresis or fractionation based on abnormal result or ethnicity. Advances in molecular genetic testing are thought to increase carrier detection. This study compares carrier screening methodologies in a multi-ethnic sperm donor population. A retrospective analysis was conducted using data from a US sperm bank. All men underwent carrier screening for hemoglobin disorders via complete blood count, hemoglobin fractionation, and molecular testing. Results were compared using counts and percentages. McNemar's exact test was used to examine differences in the marginal probabilities of screening methodologies. Of the 438 tested, 25 (5.7%) were identified as carriers of at least one hemoglobin disorder by molecular testing. Seventeen (68%) of those carriers were missed by recommended methods. No identified carriers were detected by recommended methods but missed by molecular testing. The difference between these discordant pairs was significant (p-value < 0.001). The majority (44%) of carriers were mixed ethnicity, followed by 36% White. Results indicate that molecular screening methodologies have a greater ability to detect carriers of hemoglobin disorders compared to currently recommended methods in a multi-ethnic population.

Pheochromocytoma and paraganglioma are frequently hereditary tumors commonly associated with succinate dehydrogenase (SDHx) pathogenic variants (PV). Genetic testing is recommended to relatives of patients carrying SDHx PV. This study aims to explore the experiences associated with genetic testing for this hereditary condition. Semi-structured interviews with 38 SDHx PV (tumor-affected and non-affected) carriers were transcribed and content-analyzed. Four ways of living with this genetic alteration emerged from the interviews: 'living as if not knowing', 'preventing others from going through this', 'feeling privileged', and 'still suffering'. Within each, negative, neutral, and positive reactions to the actual test result emerged initially, in addition to blame and guilt. Recognition of the importance of the genetic test and of the follow-up occurred in all four, but views on fecundity were divided between having and not having children. Consideration for the four different meanings of carrying an SDHx PV can improve participants' experiences and clinical practice.

Chromosome 5q related Spinal muscular atrophy (SMA) is an autosomal recessive, progressive, neuromuscular disorder most commonly caused by homozygous deletion of exon 7 or exon 7 and 8 of SMN1 gene. Being the leading genetic cause of infant mortality, studies of its prevalence and incidence are necessary. Carrier testing for the common pathogenic variant for SMA is offered to the couples visiting our tertiary care hospital in North India. Subjects were tested for SMA carrier status by Multiplex Ligation-dependent Probe amplification (MLPA) technique for deletion of exons 7 and 8 of SMN1 gene. The retrospective data of individuals tested for SMA carrier status in last 4 years (2016-2019) was evaluated. Six hundred and six individuals without family history of SMA or carrier of SMA who were subjected to MLPA based screening for SMA carrier status were included in the study. The carrier frequency of SMN1 deletion (deletion of exon 7 and/or exon 8) was found to be 1 in 38 (16 out of 606). The catchment area of our medical genetics clinic covering the state of Uttar Pradesh (16.5% of Indian population according to censusindia.gov.in, 2011) and neighboring states, showing SMA carrier frequency of 1:38 in a cohort with no prior positive family history has important significance for policy making.

OBJECTIVE To quantify carrier testing uptake rates for male partners of women found to be a carrier(s) for autosomal recessive conditions and to understand reasons for declining testing (uptake rate). METHODS A retrospective chart review of 513 female patients seen at Rutgers-Robert Wood Johnson Medical School found to be carriers through expanded carrier screening (ECS) panels. The aims of this study were to determine how often their male partner chose testing, reasons for declining and the type of methodology chosen for their screening. RESULTS Male partner uptake rate was 77%. We identified that the most significant barrier to male partner testing is female patients not following up on their own carrier screening results, thus missing the opportunity for partner testing. When male partners were provided options for testing, the most reported reason for declining is the belief it would have no impact on pregnancy management (20%). A carrier couple rate of 8.3% was identified of partners tested. CONCLUSION Despite a relatively high male testing uptake rate, a quarter of carrier females did not proceed with testing their partner. To ascertain fetal risk, results for both parents is necessary. Pretest counseling should stress need for potential male partner follow-up testing.

We sought to determine the costs of genetic testing and compliance with published guidelines and clinical best practices at our institution. A cost analysis was performed comparing the costs of ordered tests to the cost of the recommended testing. This was an approved quality improvement project at a tertiary teaching hospital in California. We identified charts associated with the genetic testing billing codes for common genetic tests through our contracted laboratory (cystic fibrosis genotyping, Breast cancer susceptibility gene (BRCA 1&2), Methylenetetrahydrofolate reductase (MTHFR), factor V Leiden (FVL), prothrombin gene pathogenic variant, alpha-thalassemia, hemochromatosis, and cell-free fetal DNA). Charts were reviewed retrospectively by a licensed, certified genetic counselor to assess the compliance with published clinical practice guidelines identified on GeneReviews and the American College of Obstetricians and Gynecologists (ACOG). Tests were classified as: appropriate, misordered/not indicated, misordered/false reassurance, and misordered/inadequate. We performed a cost analysis for the recommended test changes. We reviewed 114 charts over a three-month period. Forty-four (38.6%) of the tests were misordered based on published clinical practice guidelines: 24 (21%) were misordered/not indicated, 8 (7%) were misordered/false reassurance, and 12 (10.5%) were misordered/inadequate. Costs of ordered testing ($75,177) were compared to recommended testing after review ($54,265), with a total cost savings of $20,912. In clinical practice, over one-third of genetic tests reviewed were misordered. As these tests are a small fraction of all genetic tests at our institution, future studies should broaden the scope of testing evaluated to understand the magnitude of this problem and potential cost savings. Genetic counselor review and involvement in genetic test ordering can decrease inappropriate healthcare expenditures and improve patient care.

Approximately one in three Ashkenazi Jews are carriers for an autosomal recessive Jewish genetic disease (JGD). However, studies indicate that most Jews are uneducated on this topic and obstetricians do not routinely offer carrier screening to Jewish patients. Both the Reform and Conservative movements of Judaism call for JGD education to take place within the synagogue; however, little is known about the extent of this education occurring today. An online survey was created for Reform and Conservative rabbis to assess the types of JGD education taking place within the synagogue. Additionally, the survey included questions to assess JGD knowledge and possible factors that could predict counseling activity and knowledge level. Of the 94 participants, 91% had provided education about JGDs to congregants, with 98.8% providing this education during premarital counseling sessions. For most respondents, explaining recessive inheritance pattern and carrier screening was the extent of the discussion. Additionally, the majority of rabbis scored below 50% on the knowledge portion of the survey, with an average score of 1.9/4. There were no statistically significant differences between JGD education in Reform vs. Conservative synagogues, and there were no statistically significant predictors of knowledge score or JGD education frequency. In conclusion, while the number of rabbis discussing this topic is encouraging, discussion topics were found to be limited and their knowledge of JGDs was found to be poor.

Background: Globally, about 6% of children are born with a serious birth defect of genetic or partially genetic origin. Carrier screening or testing is one way to identify couples at increased risk of having a child with an autosomal recessive condition. The most common autosomal recessive conditions are thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease, with higher carrier rates in high-risk populations of specific ancestral backgrounds. Identifying and counselling couples at genetic risk of the conditions before pregnancy enables them to make fully informed reproductive decisions, with some of these choices not being available if testing is only offered in an antenatal setting. This is an update of a previously published review. Objectives: To assess the effectiveness of systematic preconception genetic risk assessment to enable autonomous reproductive choice and to improve reproductive outcomes in women and their partners who are both identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care. Search methods: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. Date of latest search of the registers: 04 August 2021. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials. Date of latest search of all these sources: 25 June 2021. Selection criteria: Any randomised controlled trials (RCTs) or quasi-RCTs (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care. Data collection and analysis: We identified 37 papers, describing 22 unique trials which were potentially eligible for inclusion in the review. However, after assessment, we found no RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease. Main results: No RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease are included. A trial identified earlier has published its results and has subsequently been listed as excluded in this review. Authors' conclusions: As there are no RCTs of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease included in either the earlier or current versions of this review, we recommend considering potential non-RCTs studies (for example prospective cohorts or before-and-after studies) for future reviews. While RCTs are desirable to inform evidence-based practice and robust recommendations, the ethical, legal and social implications associated with using this trial design to evaluate the implementation of preconception genetic risk assessment involving carrier testing and reproductive autonomy must also be considered. In addition, rather than focusing on single gene-by-gene carrier testing for specific autosomal-recessive conditions as the intervention being evaluated, preconception expanded genetic screening should also be included in future searches as this has received much attention in recent years as a more pragmatic strategy. The research evidence for current international policy recommendations is limited to non-randomised studies.

Consanguinity, the union between two individuals who are related as second cousins or closer, is a long-standing and respected tradition in many communities. Although there are social and economic benefits of consanguineous unions, offspring are at increased risk of having an inherited genetic condition or congenital anomaly. Genetic counseling services for consanguinity are available to couples at many centers. However, little is known about patient expectations of and experiences with genetic counseling for this indication, or their perspectives on genetic screening relevant to family planning, such as expanded carrier screening (ECS). This exploratory qualitative study involved interviews with 13 individuals who had recently received preconception or prenatal genetic counseling for consanguinity at a single center. We sought to gain insight into their expectations for the genetic counseling session, experiences discussing family history and reproductive risks with the genetic counselor, and views on ECS. Interview transcripts were analyzed using an interpretive descriptive approach. Data analysis revealed three main themes: (a) anticipation balances apprehension before the appointment; (b) genetic counseling reduces anxiety and empowers; and (c) the need for wider information dissemination about consanguinity-related risks and genetic services. Our findings support the personal utility of genetic counseling for consanguinity and demonstrate the need for increased visibility and access to genetics information, counseling, and testing relevant to this patient population.

Nail-Patella syndrome (NPS) is a genetic disorder generating physical malformations and, in approximately one in three cases, ocular and renal damage. The present research aimed to deeply understand patients' subjective experience with NPS, particularly the aspects of the syndrome that affect patients' adaptation and to propose interventions that can improve genetic and psychological counseling and help patients cope with their condition. Semi-structured interviews of nine people diagnosed with NPS were analyzed using interpretative phenomenological analysis. Results highlighted attempts to look like a person without disabilities by hiding malformations and not telling the truth about symptoms' genetic origin because of patients' poor self-esteem, negative self-cognition, and social isolation experienced from childhood to adulthood. Difficulties of adaptation to physical limits and pain were also identified. The majority of participants who were not diagnosed at birth tended to consider physical symptoms as “birth malformations” without imagining other potential implications until receiving a diagnosis. Despite the diagnosis, the majority continued to minimize the potential complications by considering NPS as a “physical difference” and not adhering to medical surveillance., SCOPUS: ar.j, info:eu-repo/semantics/published

The study aimed to explore with consanguineous couples in Australia the acceptability and perceived utility of whole exome reproductive carrier screening for autosomal recessive and X-linked recessive conditions. Semi-structured interviews with 21 consanguineous couples were conducted prior to the offer of screening. Interviews were coded, and thematic analysis was informed by an inductive approach. Three major themes were identified: experiences and attitudes of Australian consanguineous couples, childhood genetic conditions and beliefs, and the perceived utility of genomic screening. All but one couple had previously sought genetic advice, and a large majority of couples were aware of childhood conditions within their family or community. Thirteen couples perceived consanguinity as increasing the risk of having affected children. Nine spoke of premarital screening programs routinely conducted in their countries of origin. All supported the concept and availability of genomic reproductive carrier screening. Hypothetically, if found to be carriers of a severe childhood disorder, 13 couples reported they would test a pregnancy, and 12 of whom would consider termination of pregnancy or pre-implantation genetic diagnosis. Four couples would not test a pregnancy and two were unsure. A majority of couples would communicate potential at-risk status to family members, although there were some caveats. Fourteen couples chose to have exome screening and reported that they would utilize the results with the goal of preventing childhood conditions. Of these couples, nine (64%) had an affected child but were aware that testing may reveal they were at risk for a child with a different condition and five (71%) without an affected child. While from diverse ethnic and backgrounds, all couples practiced a religion and all but one couple were recruited from the same clinical genetics unit, with a likely higher genetic literacy and bias towards accepting genetic testing. However, the choice made by all couples was reportedly made with consideration of their personal values, their current family situation, and exome testing issues, including fear of incidental findings and concerns about test reliability.

In outbred Western populations, most individuals with intellectual disability (ID) are sporadic cases, dominant de novo mutations (DNM) are frequent, and autosomal recessive ID (ARID) is very rare. Due to the high rate of parental consanguinity which raises the risk for ARID and other recessive disorders, the prevalence of ID is significantly higher in Near- and Middle-East countries. Indeed, homozygosity mapping and sequencing in consanguineous families have already identified a plethora of ARID genes, but due to the design of these studies, DNMs could not be systematically assessed, and the proportion of cases that are potentially preventable by avoiding consanguineous marriages or through carrier testing is hitherto unknown. This prompted us to perform whole exome sequencing in 100 sporadic ID patients from Iran and their healthy consanguineous parents. In 61 patients, we identified apparently causative changes in known ID genes. Of these, 44 were homozygous recessive and 17 dominant de novo mutations. Assuming that the DNM rate is stable, these results suggest that parental consanguinity raises the ID risk about 3.6-fold, and about 4.1-4.25-fold for children of first-cousin unions. These results do not rhyme with recent opinions that consanguinity-related health risks are generally small and have been 'overstated' in the past. This article is protected by copyright. All rights reserved.

As population‐level carrier screening panels for reprogenetic information emerge globally, conditions to be included, and the timing of implementation is widely debated. Thalassemia is the only condition for which population‐based prenatal carrier screening is offered in the UK. However, little is known about the views and experiences of the UK thalassemia‐affected community toward this screening or other forms of genetic screening for thalassemia (newborn, preconception), despite the range of direct consequences of screening programmes for this group.\ud \ud Using a mixed‐methods integrative analysis (qualitative interviews n = 20 and quantitative survey n = 80), this study outlines the experiences and attitudes of adults with thalassemia, their family members, and screen‐identified thalassemia carriers toward preconception, prenatal, and newborn screening for thalassemia. The majority of participants described thalassemia as a burdensome condition with a range of negative impacts, which contributed to their strong support for screening in all its potential formats. However, the data also highlight the challenges of each screening mode for this group, reflected in the high level of value conflict in participants' accounts and decisions. Cultural, social, and (to a lesser extent) religious factors were found to mitigate against the advantages of early screens, particularly within faith communities. Social stigma emerged as key to this process, informing the way that thalassemia severity was not only perceived, but also experienced by affected adults, which ultimately influenced screening uptake and outcomes.\ud \ud These findings suggest that cultural and social sensitivity is as important as the mode of screening delivery itself, if the iatrogenic and unintended harms of screening—particularly the social/psychological burden of value conflict—are to be adequately addressed and minimized.

Objectives Expanded carrier testing is acknowledged as an acceptable strategy for carrier testing by the American College of Obstetrics and Gynecology. Limited studies have investigated positivity rates of expanded carrier panels. We describe our experience with 3 commercial laboratory panels varying in size from 3 to 218 disorders. Methods We reviewed outcomes for 3 multigene carrier screening panels: trio (3 diseases), standard (23 diseases), and global (218 diseases). All panels used targeted genotype analysis of preselected mutations via next‐generation sequencing. We calculated positivity rates for each panel. Results Positivity rates were 7.2% for Preparent Trio, 13.2% for Preparent Standard, and 35.8% for Preparent Global. The most frequent positive results in the global panel were (in descending order): abnormal hemoglobin electrophoresis, familial Mediterranean fever, cystic fibrosis, fragile X, glucose‐6‐phosphate dehydrogenase deficiency, alpha‐thalassemia, and nonsyndromic hearing loss. Conclusions While genetic diseases are individually rare, they are cumulatively common. Our experience illustrates that, with a panel of 218 diseases, the likelihood of identifying a carrier can be as high as 36%. Understanding panel positivity rates is one important factor for providers when choosing the right test for their practice, setting appropriate expectations for patients, and planning for follow‐up counseling., What's already known about this topic? Expanded carrier testing is available as an assessment option.Pan‐ethnic–based testing does not rely on ethnicity as a qualification for assessing the presence of specific genetic conditions. What does this study add? This is a report of positivity frequencies for 3 multigene carrier panels offered by a single laboratory ranging from 7.2% to 35.8%.The study includes a list of the most commonly positive conditions on a large expanded carrier panel.

Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and is caused by an expansion of cytosine-guanine-guanine (CGG) repeats in the FMR1 gene. Female premutation allele carriers (55-200 CGG repeats) are at risk to have an affected child. Currently, specific population-based carrier screening for FXS is not recommended. Previous studies exploring female premutation carrier frequency have been limited by size or ethnicity. This retrospective study provides a pan-ethnic estimate of the Fragile X premutation carrier frequency in a large, ethnically diverse population of women referred for routine carrier screening during a specified time period at Progenity, Inc. Patient ethnicity was self-reported and categorized as: African American, Ashkenazi Jewish, Asian, Caucasian, Hispanic, Native American, Other/Mixed/Unknown, or Sephardic Jewish. FXS test results were stratified by ethnicity and repeat allele category. Total premutation carrier frequency was calculated and compared against each ethnic group. A total of 134,933 samples were included. The pan-ethnic premutation carrier frequency was 1 in 201. Only the Asian group differed significantly from this frequency. Using the carrier frequency of 1 in 201, a conservative pan-ethnic risk estimate for a male fetus to have FXS can be calculated as 1 in 2,412. This risk is similar to the highest ethnic-based fetal risks for cystic fibrosis and spinal muscular atrophy, for which population-wide screening is currently recommended. This study adds to the literature and supports further evaluation into specific population-wide screening recommendations for FXS.

As expanded genome-scale carrier screening becomes increasingly prevalent, patients will face decisions about whether to receive results about a vast number of genetic conditions. Understanding patient preferences is important to meaningfully demonstrate the ethical goal of respect and support patient autonomy. We explore one possible way to elicit preferences by sorting conditions into categories, which may support patient decision making, but the extent to which categories are helpful is unknown. In the context of a randomized trial of genome sequencing for preconception carrier screening compared to usual care (single disease carrier testing), we interviewed 41 participants who had genome sequencing about their experience using a taxonomy of conditions to select categories of results to receive. We then conducted interviews with an additional 10 participants who were not randomized to genome sequencing, asking them about the taxonomy, their reasons for selecting categories, and alternative ways of presenting information about potential results to receive. Participants in both groups found the categories helpful and valued having a meaningful opportunity to choose which results to receive, regardless of whether they opted to receive all or only certain categories of results. Additionally, participants who received usual care highlighted preparedness as a primary motivation for receiving results, and they indicated that being presented with possible reasons for receiving or declining results for each category could be helpful. Our findings can be used to develop approaches, including the use of categories, to support patient choices in expanded carrier screening. Further research should evaluate and optimize these approaches.

It is generally well recognised and accepted that opportunities exist to test individuals for genetic disorders; however, the application of such genetic testing during childhood is subject to controversy and debate. The views of the child, parent and professional must be considered and how these views are weighted will vary with each and every case. For conditions where there is a recognised medical treatment, childhood genetic testing is generally justified. However, testing children for carrier status or predictively for an adult-onset condition should be approached with extreme caution. The introduction of more sophisticated genetic testing methods such as array CGH and next-generation sequencing has another level of complexity, with the increased identification of incidental findings and variants of uncertain significance. The advent of direct-to-consumer testing and advances in prenatal and newborn testing have also influenced the debate about testing in childhood. Key Concepts Genetic tests may be diagnostic, predictive or assess carrier status. Genetic testing may be performed prenatally, in the newborn period, in childhood, adulthood or on stored DNA from deceased relatives. Childhood genetic testing is generally instigated by parents/guardians, but the views and opinions of children must be sought. Testing in childhood that is performed predictively or to assess carrier status takes away the child's right to decide on testing for themselves when older. New genetic testing technologies increase the diagnostic rate but may identify uncertain or incidental findings. Keywords: genetic testing; childhood testing; predictive testing; carrier testing; adult-onset disorders; consent; incidental findings; direct-to-consumer testing; next-generation sequencing; prenatal testing

Objectives The objective of this study is to report 6-year clinical prenatal diagnosis experience of Duchenne muscular dystrophy (DMD)-affected families evaluated at a single prenatal diagnosis center in China and establish a reliable and rational prenatal diagnosis procedure for DMD families. Methods The prenatal diagnosis data of 146 at-risk pregnancies in 131 DMD families referred to our center from 2010 to 2016 were retrospectively reviewed. Results The mutation detection rate of the probands was greater than 99%. In the 131 families, 50 mothers showed negative results during carrier testing, and de novo exon deletions arose in 51.1% of the probands. Of the 146 pregnancies, 91 were male fetuses, 34 of which were affected. Germline mosaicism was identified three times in this cohort, and recombination of the DMD gene was detected in nine cases. Conclusions Accurate genetic diagnosis of the proband is important for preventing recurrence in at-risk families. The present results demonstrate the importance of considering maternal germline mosaicism in the genetic assessment. Prenatal diagnosis should be suggested to the parent with a DMD proband whether carrier testing found the causative mutation in the mother's blood or not. Finally, we have developed a prenatal diagnosis algorithm for dystrophinopathies that combines multiplex ligation-dependent probe amplification, quantitative PCR, sequencing and linkage analyses. © 2017 John Wiley & Sons, Ltd.

Pheochromocytoma and paraganglioma (PPGL) are rare tumours and at least 30% are part of hereditary syndromes. Approximately 20% of hereditary PPGL are caused by pathogenic germ line variants in genes of the succinate dehydrogenase complex (SDHx), TMEM127 or MAX. Herein we present guidelines regarding genetic testing of family members and their surveillance based on a thorough literature review. All cases of PPGL are recommended genetic testing for germ line variants regardless of patient and family characteristics. At minimum, FH, NF1, RET, SDHB, SDHD and VHL should be tested. In addition, testing of MEN1, SDHA, SDHAF2, SDHC, TMEM127 and MAX is recommended. Healthy first-degree relatives (and second-degree relatives in the case of SDHD and SDHAF2 which are maternally imprinted) should be offered carrier testing. Carriers of pathogenic variants should be offered surveillance with annual biochemical measurements of methoxy-catecholamines and bi-annual rapid whole-body magnetic resonance imaging and clinical examination. Surveillance should start 5 years before the earliest age of onset in the family and thus only children eligible for surveillance should be offered pre-symptomatic genetic testing. The surveillance of children younger than 15 years needs to be individually designed. Our guidelines will provide a framework for patient management with the possibility to follow outcome via national registries and/or follow-up studies. Together with improved insights into the disease, this may enable optimisation of the surveillance scheme in order to minimise both anxiety and medical complications while ensuring early disease detection.

Genetic carrier testing includes tests for the heterozygous status of an inherited disorder in individuals who, although apparently healthy themselves, have a high risk of transmitting the genetic disorder to their offspring. Carrier testing will allow couples of childbearing age to make informed reproductive decisions. Genetic carrier tests are used by people who have a family history of an inherited disorder or carriership, reproductive partners of carriers and partners of individuals who have the disorder. A prerequisite for knowledge about a possible risk for relatives and the availability of testing is the dissemination of information in the family. Many factors impede the sharing of genetic information in families including lack of knowledge, persistent lay beliefs or poor relationships. In addition, several factors have been identified that interfere with decisions about genetic carrier testing, resulting in low uptake rates for carrier tests in high risk families. Key concepts Reproductive planning is the most important factor motivating genetic carrier testing. Family disclosure of genetic information is a prerequisite to knowledge about the risk and availability of carrier testing. Because of factors impeding the sharing of information in families and factors interfering with the decision about testing, the uptake for carrier testing in high-risk families is often lower than expected. To minimize (time) constraints and maximize reproductive options, carrier testing before conception is advocated. Keywords: carrier status; genetic testing; genetic risk; family communication; psychological impact

When a child is identified with a genetic condition, some parents want to know the carrier status of their other children. There has been little exploration of why parents want this information. To address this question, semi-structured interviews were conducted with parents of 32 children with cystic fibrosis, haemophilia, and Duchenne muscular dystrophy who wanted to know the carrier status of their other children. Data was analyzed using inductive content analysis. Parents expressed a range of reasons for desiring their child's carrier status, which fell into two broad categories: 1) benefit for the parents and 2) perceived benefit to the child. Parents discussed the desire for certainty and peace of mind derived from having knowledge of their child's status. The most commonly expressed reason for wanting to know their child's carrier status was in order to communicate the information to their child to provide them with the ability to make informed reproductive decisions. These reasons suggest parents are seeking their children's carrier information both as a coping strategy and to communicate carrier information as part of their role as a parent. This has important implications for genetic counseling practice, especially as international guidelines generally recommend against carrier testing in children.

As genome or exome sequencing (hereafter genome-scale sequencing) becomes more integrated into standard care, carrier testing is an important possible application. Carrier testing using genome-scale sequencing can identify a large number of conditions, but choosing which conditions/genes to evaluate as well as which results to disclose can be complicated. Carrier testing generally occurs in the context of reproductive decision-making and involves patient values in a way that other types of genetic testing may not. The Kaiser Permanente Clinical Sequencing Exploratory Research program is conducting a randomized clinical trial of preconception carrier testing that allows participants to select their preferences for results from among broad descriptive categories rather than selecting individual conditions. This paper describes (1) the criteria developed by the research team, the return of results committee (RORC), and stakeholders for defining the categories; (2) the process of refining the categories based on input from patient focus groups and validation through a patient survey; and (3) how the RORC then assigned specific gene-condition pairs to taxonomy categories being piloted in the trial. The development of four categories (serious, moderate/mild, unpredictable, late onset) for sharing results allows patients to select results based on their values without separately deciding their interest in knowing their carrier status for hundreds of conditions. A fifth category, lifespan limiting, was always shared. The lessons learned may be applicable in other results disclosure situations, such as incidental findings.

Carrier testing is widely available for multiple genetic conditions, and several professional organizations have created practice guidelines regarding appropriate clinical application and the testing of minors. Previous research has focused on carrier screening, predictive testing, and testing for X-linked conditions. However, family perspectives on carrier testing for X-linked lethal diseases have yet to be described. In this study, we explored communication within the family about carrier testing and the perspectives of mothers of sons with an X-linked lethal disease, Duchenne muscular dystrophy (DMD). Twenty-five mothers of sons with DMD participated in an anonymous online survey. Survey questions included multiple choice, Likert scale, and open ended, short answer questions. Analysis of the multiple choice and Likert scale questions revealed that most mothers preferred a gradual style of communication with their daughters regarding risk status. In addition, most participants reported having consulted with a genetic counselor and found it helpful. Comparisons between groups, analyzed using Fisher's exact tests, found no differences in preferred style due to mother's carrier status or having a daughter. Thematic analysis was conducted on responses to open ended questions. Themes identified included the impact of family implications, age and maturity, and a desire for autonomy regarding the decision to discuss and undergo carrier testing with at-risk daughters, particularly timing of these discussions. Implications for genetic counseling practice are discussed.

X-linked myotubular myopathy (XLMTM) is a congenital neuromuscular disorder defined by severe hypotonia, respiratory failure and histopathologic changes in muscle biopsy. The objective of this report is to inform about our experience of genetic analysis on a group of 25 unrelated XLMTM patients, clinically diagnosed by several Italian and European Medical Institutes from 2006 to 2015. The molecular strategy used for genotyping involved Sanger sequencing of coding and intron/exon regions and the Multiplex Ligation Probe Amplification method. A total of 13 different point variants (6 nonsense, 5 missense, 1 splicing and 1 small deletion) were found in 15 patients (60%). Three were new missense variants: c.185G>T p.(Arg62Ile), c.719T>A p.(Val240Glu), and c.1262G>T p.(Arg421Leu). No large duplications/deletions have been identified. We performed carrier testing of at-risk female relatives. Only one mutation was de novo. Successively, we offered XLMTM prenatal testing for seven pregnancies in five unrelated families. In this context, the aim to propose an effective molecular diagnostic service is to confirm clinical XLMTM diagnosis, to monitor the cause-disease mutation segregation in the family and to offer genetic counseling to have correct information regarding offspring risks and the prenatal testing.

Only 5% of breast cancers are explained by highly penetrant multisystem autosomal dominant hereditary disorders. Though another 20-30% has a familial presentation, the genetic and other etiologies are still not well understood. Genetic testing is now widely available and multiple professional societies have published guidelines for testing and management. Genetic testing trends include utilization of multi-gene panels that take advantage of next-generation sequencing as well as testing for low- and moderate-penetrance susceptibility genes.

Introduction Spinal muscular atrophy (SMA) is a severe autosomal recessive genetic disease that occurs in about one in every 10 000 births. Prenatal carrier testing is available for SMA, and the utility of universal screening is actively debated. Objective The aim of this study was to perform a systematic review and meta-analysis of SMA genotype frequency, carrier frequency, and carrier test performance in different ethnic groups. Methods We performed a systematic review of the literature for studies on SMA carrier screening test performance. Ethnicity-specific allele frequencies, carrier rates, and screening test performance were determined from data of 169 000 individuals in 14 published studies. Pooled estimates were calculated for each ethnic group using a random effects meta-analysis. Results The detection rate of SMA screening in the non-Black population was 87–95%; however, detection rates fell to 71% among the Black population. Conclusion These results highlight that although SMA carrier testing generally performs well and could be considered as a routine prenatal screen, SMA testing should be used cautiously in the Black population. © 2014 John Wiley & Sons, Ltd.

Osteopetrosis is a rare and heterogeneous genetic disorder characterized by dense bone mass that is a consequence of defective osteoclast function and/or development. Autosomal recessive osteopetrosis (ARO) is the most severe form and is often fatal within the first years of life; early hematopoietic stem cell transplant (HSCT) remains the only curative treatment for ARO. The majority of the ARO-causing mutations are located in the TCIRG1 gene. We report here the identification and characterization of an A to T transversion in the fourth base of the intron 2 donor splice site (c.117+4A→T) in TCIRG1, a mutation not previously seen in the Ashkenazi Jewish (AJ) population. Analysis of a random sample of individuals of AJ descent revealed a carrier frequency of approximately 1 in 350. Genotyping of five loci adjacent to the c.117+4A→T-containing TCIRG1 allele revealed that the presence of this mutation in the AJ population is due to a single founder. The identification of this mutation will enable population carrier testing and will facilitate the identification and treatment of individuals homozygous for this mutation.

Developmental disabilities and sensory impair- ments have a wide range of genetic and envi- ronmental causes. Recognized environmental insults include in utero exposure to infections or teratogens (e.g., alcohol, prescription medica- tions, illegal drugs), birth trauma, and premature birth. Genetic causes range from large genome imbalances (such as Down syndrome, or Tri- somy 21, in which there is an extra copy of an entire chromosome) to something as small as one pathogenic DNA variant in a single gene.Genetic abnormalities can occur de novo (a new genetic abnormality not transmitted from either parent) or they can be inherited in several recognizableMendelianpatterns,includingfrom carrier parents who themselves are apparently healthy but who have an increased risk for a serious health problem in their children. Knowledge about heritable risks has long been of interest to parents. For the most part, carrier testing for inherited disorders historically has been disease specific, focusing on severely disabling or life-threatening conditions such as Tay-Sachs disease and cystic fibrosis. But five recent phenomena have forced a rethinking of views and practices regarding the detection of heritable conditions.PHENOMENA AFFECTING DETECTION OF HERITABLE CONDITIONSMore disorders causing disability are recognized as having an inherited componentBasic research on underlying disease processes has led to the identification of inheritance mechanisms for an increasingly large number of disorders. Bell et al. (2011), drawing on data from the Online Mendelian Inheritance in Man (OMIM), reported that there are 7,028 disorders with a suspected Mendelian inheritance, of which only about 16% (1,139) are autosomal recessive (requiring two carrier parents before the disease is manifest in children).Complex notions of genetic susceptibility and riskGenome-wide association studies are pro- viding new insights into genetic suscepti- bility for conditions such as schizophrenia, bipolar disorder, autism, or attention-deficit/ hyperactivity disorders (ADHD; Gershon & Alliey-Rodriguez, 2013). Genetic susceptibility means that genetic changes have been associ- ated with elevated risk for having the disorder at the population level. But the factors determining whether or how the disorder is expressed in an individual are not well understood.Although many types of intellectual and developmental disabilities are predicted to have an underlying causal genetic component, far fewer cases can be confidently ascribed to a single gene mutation. Although Mendelian forms certainly exist, with the X chromosome harboring many genes crucial for normal brain development, many cases of intellectual disabilities are classified as ''familial.'' This classification assumes that a genetic component is present because of its occurrence in multiple biologic relatives, but the family history does not fit a Mendelian pattern of inheritance of a single gene. Rather, the term multifactorial is commonly used to describe the combination of genetic and environmental factors that occur together in the affected individual. A polygenic risk score has been proposed as a way to summarize genetic effects for traits or conditions in which no single gene is implicated but for which a composite score of multiple genetic components can be calculated to provide an overall summary of heritability (Dudbridge, 2013). Because members of a family share many alleles (versions of a gene) as well as many environmental factors in common, it is oftendifficulttountangletheirrelevantcausative roles. Hamshere et al. (2013) provide a recent example of how a polygenic risk score is associated with ADHD, an association that is further strengthened if children with ADHD also have comorbid aggression.Other contributions to gene expression or disruptionIt is becoming increasingly apparent that the bio- logical and physical environment can affect gene expression, a phenomenon generally referred to as ''epigenetics'' (cf. …

Objective The objective of this study is to assess the opinions of Fellows of the American College of Obstetricians and Gynecologists on expanded carrier testing (molecular detection of >100 genetic diseases of variable severity) and noninvasive prenatal testing (NIPT). Methods A survey conducted between March and August 2012, assessed current use of testing, provision of genetic counseling, types of disorders that should be identified, preferences for future use, ethical aspects, and views on regulatory oversight. Results Expanded carrier testing was offered to all patients by 15% of the responders and 52.1% upon patient request. Most (67.3%) favored testing only for mutations of known significance. In this study, 79.1% supported the use of NIPT as a screen for Down syndrome for all women with 47.9% viewing NIPT as a complete substitution for invasive testing. Most supported expansion to other aneuploidies (97.5%) and severe early-onset Mendelian disorders (90.4%) but not for adult-onset disorders (29.8%) or nonmedical sex identification (15.7%). A majority (73.2%) believed that NIPT would increase pregnancy terminations for mild disease states. Respondents favored a role for professional societies in providing regulatory oversight. Conclusion Rapid incorporation of new genetic technologies may be limited by the availability of genetic counseling, concerns regarding inclusion of clinically mild disorders, results of unknown significance, and costs. © 2013 John Wiley & Sons, Ltd.

To provide practice recommendations for genetic counselors whose clients are considering cystic fibrosis (CF) carrier testing or seeking information regarding CF molecular test results. The goals of these recommendations are to: 1) Provide updated information about the natural history, diagnosis, and treatment of CF and related conditions. 2) Supplement genetic counselors’ knowledge and understanding of the available carrier screening and diagnostic testing options. 3) Describe the current state of genotype/phenotype correlations for CFTR mutations and an approach to interpreting both novel and previously described variants. 4) Provide a framework for genetic counselors to assist clients’ decision-making regarding CF carrier testing, prenatal diagnosis, and pregnancy management. Disclaimer The practice guidelines of the National Society of Genetic Counselors (NSGC) are developed by members of the NSGC to assist genetic counselors and other health care providers in making decisions about appropriate management of genetic concerns; including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue, and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the NSGC practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are only current as of their publication date, and are subject to change without notice as advances emerge. In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health care provider’s best medical judgment based on the clinical circumstances of a particular patient or patient population. Practice guidelines are published by NSGC for educational and informational purposes only, and NSGC does not “approve” or “endorse” any specific methods, practices, or sources of information.

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease and the most common genetic cause of infant mortality, affecting ∼1 in 10,000 live births. The disease is characterized by progressive symmetrical muscle weakness resulting from the degeneration and loss of anterior horn cells in the spinal cord and brain stem nuclei. The disease is classified on the basis of age of onset and clinical course. SMA is caused by mutations in the telomeric copy of the survival motor neuron 1 (SMN1) gene, but all patients retain a centromeric copy of the gene, SMN2. The homozygous absence of the SMN1 exon 7 has been observed in the majority of patients and is being utilized as a reliable and sensitive SMA diagnostic test. In the majority of cases, the disease severity correlates inversely with an increased SMN2 gene copy number. Carrier detection, in the deletion cases, relies on the accurate determination of the SMN1 gene copies. Since SMA is one of the most common lethal genetic disorders, with a carrier frequency of 1 in 40 to 1 in 60, direct carrier dosage testing has been beneficial to many families. This unit attempts to highlight the molecular genetics of SMA with a focus on the advantages and limitations of the current molecular technologies.