Molecular testing in newborn screening: VUS burden among true positives and secondary reproductive limitations via expanded carrier screening panels

PURPOSE

Expanded carrier screening (ECS) gene panels have several limitations, including variable content, current knowledge of disease-causing variants, and differing reporting policies. This study evaluated if the disease-associated variants identified in affected neonates who screened positive by California newborn screening (NBS) for an inherited metabolic disorder (IMD) by tandem mass spectrometry (MS/MS) would likely be reported by ECS gene panels.

METHODS

Retrospective review of neonates referred by the California Department of Public Health for a positive NBS by multianalyte MS/MS from January 1, 2020 through June 30, 2021.

RESULTS

One hundred thirty-six neonates screened positive for ≥1 NBS MS/MS indication. Nineteen neonates (14%) were ultimately diagnosed with an IMD, all of whom had abnormal biochemical testing. Eighteen of the 19 underwent molecular testing; 10 (56%) neonates had ≥1 variants of uncertain significance, 9 of whom were of non-White ancestry. ECS panels would have been negative for 56% (20/36) of parents with an affected neonate, 85% (17/20) of whom were of non-White ancestry.

CONCLUSION

The number of variants of uncertain significance identified in this cohort highlights the need for more diversified variant databases. Due in part to the lack of diversity in currently sequenced populations, genomic sequencing cannot replace biochemical testing for the diagnosis of an IMD.

Prevalence of common autosomal recessive mutation carriers in women in the Southern Vietnam following the application of expanded carrier screening

The common autosomal recessive (AR) mutation carrier is still unknown in Vietnam. This study aims to identify the most common AR gene mutation carriers in women of reproductive age to build a Vietnamese-specific carrier screening panel for AR and X-linked disorders in the preconception and prenatal healthcare program. A cross-sectional study was conducted at University Medical Center-Branch 2 in Ho Chi Minh City from December 1st, 2020, to June 30th, 2023. 338 women have consented to take a 5 mL blood test to identify 540 recessive genes. The carrier screening panel was designed based on the American College of Medical Genetics and Genomics (ACMG)-recommended genes and suggestions from 104 clinical experts in Vietnam. Obstetricians and genetic experts counseled all positive testing results to discuss the possibility of recessive diseases in their offspring. The most common recessive disorders were defined at a prevalence of 1 in 60 or greater, and those were added to a Vietnamese-specific carrier screening panel. 338 non-pregnant and pregnant women underwent the expanded carrier screening (ECS). The carrier frequency was 63.6%, in which 215 women carried at least one AR gene mutation. GJB2 hearing impairment was identified as the most common chronic condition (1 in 5). The second most common AR disorder was beta-thalassemia (1 in 16), followed by cystic fibrosis (1 in 23), G6PD deficiency (1 in 28), Wilson's disease (1 in 31), Usher's syndrome (1 in 31), and glycogen storage disease (1 in 56). Seven common recessive genes were added in ethnic-based carrier screening. Women in the South of Vietnam have been carried for many recessive conditions at high frequency, such as hearing impairment, genetic anemia, and cystic fibrosis. It is necessary to implement a preconception and prenatal screening program by using seven widely popular AR genes in a Vietnamese-specific carrier screening panel to reduce the burden related to AR and X-linked disorders.

Perceptions of reproductive healthcare providers regarding their involvement in offering expanded carrier screening in fertility clinics: a qualitative study

RESEARCH QUESTION

What are the main arguments of reproductive healthcare providers in favour or against their involvement in offering expanded carrier screening (ECS) for recessive disorders at fertility clinics in the Netherlands?

DESIGN

Semi-structured interview study with 20 reproductive healthcare providers between May 2020 and January 2021. Participants included 11 gynaecologists, seven fertility doctors, one nurse practitioner and one clinical embryologist, recruited from academic medical centres (n = 13), peripheral facilities associated with academic centres (n = 4), and independent fertility treatment centres (n = 3) in the Netherlands. An interview guide was developed, and thematic content analysis was performed using ATLAS.ti software.

RESULTS

Arguments of reproductive healthcare providers in favour of their potential involvement in offering ECS included: (i) opportunities offered by the setting; (ii) motivation to assist in reproduction and prevent suffering; and (iii) to counter unwanted commercialization offers. Arguments against involvement included: (i) lack of knowledge and familiarity with offering ECS; (ii) insufficient staff and resources, and potential high costs for clinics and/or couples; (iii) the emotional impact it may have on couples; (iv) perceived complexity of counselling and expected elongation of waiting lists; and (v) expected low impact on reducing the burden of diseases. Participants felt that more evidence and research on the costs-benefits, implications and demand are needed prior to their involvement.

CONCLUSION

While agreeing that the field of medically assisted reproduction provides a unique opportunity to offer ECS, reproductive healthcare workers feel a lack of capability and limited motivation to offer ECS to all or a selection of couples at their fertility clinics.

Investigation of interest in and timing preference for cancer predisposition testing and expanded carrier screening among women of reproductive age

Objective

To examine cognitive, relational, and social predictors of interest in and timing preference for cancer predisposition testing (CPT) and expanded carrier screening (ECS) offered in routine gynecologic care for women of reproductive age.

Methods

Women between 20 and 35 years old who were currently pregnant or had a prior pregnancy (N = 351) completed an online survey. Bivariate and multivariable analyses were used to identify significant predictors of women's interest in and timing preference for CPT and ECS.

Results

Most respondents reported high interest in CPT and ECS and preferred to have them when planning for a pregnancy. Perceived importance of genetic information and negative attitude towards uncertainty predicted interest in CPT and ECS in multivariable models. Genetic knowledge predicted preference for CPT or ECS when planning for a pregnancy.

Conclusion

Educational and decision support tools should be developed to enhance women's knowledge and awareness of CPT and ECS and to provide them with strategies to manage uncertainty.

Innovation

We examined women's timing preference for CPT and ECS and the impact of partner support and trust with gynecologist. A context-specific attitudes toward uncertainty scale was used to investigate women's particular perceptions of uncertainty in genetic testing.

Management considerations for clinically relevant findings on expanded carrier screening in a sperm donor applicant population

Objective

To describe the clinical experience of managing expanded carrier screening (ECS) results in sperm donor applicants at a sperm bank in the United States, including considerations around suitability determination and appropriate education of prospective donors and recipients.

Design

A retrospective review of donor genetic screening records from July 2017 to December 2021.

Setting

A U.S.-based sperm bank.

Patients

Donor applicants at a sperm bank.

Intervention

Not applicable.

Main Outcome Measures

To examine the rate of potentially significant health risks on the basis of ECS results to inform donor management and donor/recipient counseling considerations.

Results

Nearly 2% of donor applicants were identified as having potentially significant health risks on the basis of their ECS results, and most individuals had no clinical manifestations related to these findings.

Conclusion

There are unique challenges related to ECS in third-party reproduction for gamete providers, recipients, and their healthcare providers. A collaborative, multidisciplinary approach is necessary to help mitigate risks to donor offspring and maximize patient experience. Informed consent and access to a trained genetics professional are paramount when facilitating ECS on donor applicants and disseminating results to recipients.

Benefits and concerns of expanded carrier screening: what do pregnant Latina women in Texas think?

The American College of Medical Genetics and Genomics (ACMG) recommends carrier screening for all pregnant women regardless of race or ethnicity. In recent years, the ACMG broadened the guidelines to include expanded carrier screening (ECS) which can screen for 112 conditions. This study seeks to explore the perceptions of pregnant Latina women about the benefits and concerns related to ECS use. Partnering with prenatal clinics in Texas, we conducted semi-structured qualitative interviews with 32 pregnant Latina women in their second or third trimester of pregnancy. NVivo 8 was used to conduct content analysis and emergent coding of the data. Participants reported the benefits of ECS as helping them prepare for the baby's arrival, informing them of the baby's risk for genetic conditions, ensuring the health of their baby, and preventing diseases before birth. The ECS-related concerns expressed by the participants included worries surrounding potential positive ECS results, insufficient knowledge about the genetic diseases screened for by ECS, the accuracy of the ECS, the potential harm ECS may cause the baby, and the affordability of ECS. After weighing both their perceived benefits and concerns, nearly all the participants believed that ECS should be offered to all pregnant women. This study contributes to an understudied research area in the genetic/genomic field. Our findings can help increase the awareness of obstetricians, genetic professionals, and other healthcare providers regarding pregnant Latina women's views on ECS and inform the design of culturally appropriate care as ECS is adopted into routine clinical practice.

Implementing preconception expanded carrier screening in a universal health care system: A model-based cost-effectiveness analysis

PURPOSE

The limited evidence available on the cost-effectiveness (CE) of expanded carrier screening (ECS) prevents its widespread use in most countries, including Italy. Herein, we aimed to estimate the CE of 3 ECS panels (ie, American College of Medical Genetics and Genomics [ACMG] Tier 1 screening, "Focused Screening," testing 15 severe, highly penetrant conditions, and ACMG Tier 3 screening) compared with no screening, the health care model currently adopted in Italy.

METHODS

The reference population consisted of Italian couples seeking pregnancy with no increased personal/familial genetic risk. The CE model was developed from the perspective of the Italian universal health care system and was based on the following assumptions: 100% sensitivity of investigated screening strategies, 77% intervention rate of at-risk couples (ARCs), and no risk to conceive an affected child by risk-averse couples opting for medical interventions.

RESULTS

The incremental CE ratios generated by comparing each genetic screening panel with no screening were: -14,875 ± 1,208 €/life years gained (LYG) for ACMG1S, -106,863 ± 2,379 €/LYG for Focused Screening, and -47,277 ± 1,430 €/LYG for ACMG3S. ACMG1S and Focused Screening were dominated by ACMG3S. The parameter uncertainty did not significantly affect the outcome of the analyses.

CONCLUSION

From a universal health care system perspective, all the 3 ECS panels considered in the study would be more cost-effective than no screening.

Carrier burden of over 300 diseases in Han Chinese identified by expanded carrier testing of 300 couples using assisted reproductive technology

BACKGROUND

Expanded carrier screening (ECS) has become a common practice for identifying carriers of monogenic diseases. However, existing large gene panels are not well-tailored to Chinese populations. In this study, ECS testing for pathogenic variants of both single-nucleotide variants (SNVs) and copy number variants (CNVs) in 330 genes implicated in 342 autosomal recessive (AR) or X-linked diseases was carried out. We assessed the differences in allele frequencies specific to the Chinese population who have used assisted reproductive technology (ART) and the important genes to screen for in this population.

METHODOLOGY

A total of 300 heterosexual couples were screened by our ECS panel using next-generation sequencing. A customed bioinformatic algorithm was used to analyze SNVs and CNVs. Guidelines from the American College of Medical Genetics and Genomics and the Association for Molecular Pathology were adapted for variant interpretation. Pathogenic or likely pathogenic (P/LP) SNVs located in high homology regions/deletions and duplications of one or more exons in length were independently verified with other methods.

RESULTS

64.83% of the patients were identified to be carriers of at least one of 342 hereditary conditions. We identified 622 P/LP variants, 4.18% of which were flagged as CNVs. The rate of at-risk couples was 3%. A total of 149 AR diseases accounted for 64.05% of the cumulative carrier rate, and 48 diseases had a carrier rate above 1/200 in the test.

CONCLUSION

An expanded screening of inherited diseases by incorporating different variant types, especially CNVs, has the potential to reduce the occurrence of severe monogenic diseases in the offspring of patients using ART in China.

Updates in Genetic Screening for the General Obstetrician

The number of prenatal genetic screening options, including aneuploidy screening and carrier screening, has drastically increased with rapid advancements in DNA sequencing technologies. Noninvasive prenatal screening analyzing cell-free DNA has quickly been integrated into routine prenatal care as it is the most sensitive and specific screening method for pregnancies at increased and average risk of fetal aneuploidy. The aim of this article is to outline current recommendations for cell-free DNA screening and carrier screening, important aspects of pretest and posttest counseling for obstetric providers, and which patients should be referred to a genetic specialist.

Barriers to Completion of Expanded Carrier Screening in an Inner City Population

PURPOSE

The American College of Medical Genetics and Genomics emphasizes a "consistent and equitable approach for offering carrier screening". At our academic center, publicly insured prenatal patients underwent universal Expanded Carrier Screening (ECS) to promote equitable care. The aim of the study was to evaluate rates, time, and barriers to complete ECS. This was defined as post-test counseling and partner testing after a patient was found heterozygous for a pathogenic variant.

METHODS

A descriptive retrospective cohort study from 2018-2021. Patients were offered ECS, consisting of 283 recessive and X-linked genes. Heterozygotes were contacted by genetic counselors (</=5 attempts), for education and partner testing. Rates of counseling, partner testing, diagnostic procedures, follow up times, and barriers to completion were assessed.

RESULTS

During this time, 643 women underwent ECS. 462/643 were heterozygotes and 326/462 had counseling. 222/462 partners obtained testing, with a median of 32 days from patient to partner result. 21 couples were heterozygous for the same pathogenic variant. One patient pursued diagnostic testing.

CONCLUSION

ECS offers useful information, however, this study highlights significant barriers to completion. There was suboptimal patient follow up and low partner screening, perhaps from insufficient time to educate and counsel. Future directions include implementing quality measures to ensure optimal completion.

Clinical application value of expanded carrier screening in the population of childbearing age

OBJECTIVE

The objective of this study was to explore the clinical utility of the implementation of expanded carrier screening (ECS) in Chinese population of childbearing age.

MATERIALS AND METHODS

Based on capillary electrophoresis, a first-generation sequencing technology, a prospective screening study of carriers of 15 single-gene diseases was carried out in 327 subjects in Anhui Province, including 84 couples and 159 women of childbearing age, the disease carrier rate, types of screened pathogenic genes, and incidence of both partners carrying the same pathogenic genes were summarized and analyzed.

RESULTS

In 320 people with normal phenotypes who underwent ECS for 15 genetic diseases and 7 spouses who underwent targeted gene sequencing, 65 carriers of at least one disease were detected, with a total carrier rate of 20.31% (65/320). Among the 65 carriers, 81.54% (53/65) carried one genetic variant, 16.92% (11/65) carried two genetic variants, and 1.54% (1/65) carried three genetic variants. In this study, the three diseases with the highest carrier rates were hereditary deafness (8.13%, 26/320), Wilson's disease (4.06%, 13/320), and phenylketonuria (3.13%, 10/320). One high-risk couple (1.19%, 1/84) was detected.

CONCLUSIONS

It has certain clinical application value to implement ECS in the population of childbearing age in China.

A guidelines-consistent carrier screening panel that supports equity across diverse populations

PURPOSE

The American College of Obstetricians and Gynecologists (ACOG) and the American College of Medical Genetics and Genomics (ACMG) suggest carrier screening panel design criteria intended to ensure meaningful results. This study used a data-driven approach to interpret the criteria to identify guidelines-consistent panels.

METHODS

Carrier frequencies in >460,000 individuals across 11 races/ethnicities were used to assess carrier frequency. Other criteria were interpreted on the basis of published data. A total of 176 conditions were then evaluated. Stringency thresholds were set as suggested by ACOG and/or ACMG or by evaluating conditions already recommended by ACOG and ACMG.

RESULTS

Forty and 75 conditions had carrier frequencies of ≥1 in 100 and ≥1 in 200, respectively; 175 had a well-defined phenotype; and 165 met at least 1 severity criterion and had an onset early in life. Thirty-seven conditions met conservative thresholds, including a carrier frequency of ≥1 in 100, and 74 conditions met permissive thresholds, including a carrier frequency of ≥1 in 200; thus, both were identified as guidelines-consistent panels.

CONCLUSION

Clear panel design criteria are needed to ensure quality and consistency among carrier screening panels. Evidence-based analyses of criteria resulted in the identification of guidelines-consistent panels of 37 and 74 conditions.

Attitudes of sperm donors towards offspring, identity release and extended genetic screening

RESEARCH QUESTION

What is sperm donors' attitude towards offspring, anonymity and extended genetic screening?

DESIGN

An online questionnaire for sperm donors was administered at Cryos International in the USA and Denmark between 9 and 30 September 2020. A total of 233 donors (37 in the USA and 196 in Denmark) completed the questionnaire. This study is unique because it was performed in a setting that allows donors to choose to be either ID-release or non-ID-release donors.

RESULTS

Most donors had two motives to donate: helping childless people and/or financial compensation. ID-release donors differed significantly from non-ID-release donors in numerous aspects of the donation, including relationships with the offspring, information sharing with others and wanting information about offspring. In general, donors had a very positive attitude towards genetic testing and extended genetic screening.

CONCLUSIONS

Offering the possibility for donors to be either ID-release or non-ID-release allows more donors to be recruited than if only one option were available. The multiple differences between the two donor types suggests that these are groups with profoundly different attitudes towards donation. The general attitude of donors towards genetic testing and expanded genetic screening is very positive but further studies on the attitude of candidate donors are needed.

Legal challenges in reproductive genetics

Recent advancements in reproductive genetics have resulted in the availability of an extraordinary amount of new and detailed information for patients and providers. Whereas this information can inform many who are facing difficult clinical decisions, it can also introduce complex and uncertain choices. Expanded carrier screening and preimplantation genetic diagnosis for aneuploidy are important examples of new genetic techniques that are now widely used in reproductive medicine. This paper will explore these techniques through a medical-legal prism to better understand the opportunities and obligations incumbent on both patients and providers in this new age of genetic diagnosis.

Preconception expanded carrier screening: a focus group study with relatives of mucopolysaccharidosis type III patients and the general population

Preconception expanded carrier screening (ECS) enables prospective parents to assess their risk of having a child with an autosomal recessive disorder. Knowledge on motivations, feelings, and considerations people have towards the offer and use of ECS is limited. To enrich the public and professional discussion on ECS implementation, this study explored the perspectives towards various aspects of ECS in seven focus groups compromising first- and second-degree relatives of MPS III patients (N=9, N=4, N=5, N=5) and members of the general Dutch population (N=6, N=7, N=5). The focus groups were audio recorded and the transcripts were qualitatively analyzed to identify themes. Both relatives of MPS III patients and participants from the general population supported offering ECS, in particular for severe, childhood-onset disorders. Important barriers identified for ECS were a lack of genetic knowledge and a perceived lack of personal relevance and awareness, as well as out-of-pocket costs of testing. The majority of participants would prefer full disclosure of individual test results instead of couple-based test results. Moreover, offering people a choice for the way of reporting was proposed. All participants agreed that more efforts, for example by governmental campaigns, should be made to increase awareness on the availability, potentials, and limitations of ECS. Educating prospective parents about ECS is essential for increasing awareness and informed decision making. This study provides valuable insights that can be used by governments and public health authorities when considering implementation of preconception ECS.

First French study relative to preconception genetic testing: 1500 general population participants' opinion

Background

Until very recently, preconception genetic testing was only conducted in particular communities, ethnic groups or families for which an increased risk of genetic disease was identified. To detect in general population a risk for a couple to have a child affected by a rare, recessive or X-linked, genetic disease, carrier screening is proposed in several countries. We aimed to determine the current public opinion relative to this approach in France, using either a printed or web-based questionnaire.

Results

Among the 1568 participants, 91% are favorable to preconception genetic tests and 57% declare to be willing to have the screening if the latter is available. A medical prescription by a family doctor or a gynecologist would be the best way to propose the test for 73%, with a reimbursement from the social security insurance. However, 19% declare not to be willing to use the test because of their ethic or moral convictions, and the fear that the outcome would question the pregnancy. Otherwise, most participants consider that the test is a medical progress despite the risk of an increased medicalization of the pregnancy.

Conclusion

This first study in France highlights a global favorable opinion for the preconception genetic carrier testing under a medical prescription and a reimbursement by social security insurance. Our results emphasize as well the complex concerns underpinned by the use of this screening strategy. Therefore, the ethical issues related to these tests include the risk of eugenic drift mentioned by more than half of the participants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01754-z.

Expanded carrier screening for recessively inherited disorders: economic burden and factors in decision-making when one individual in a couple is identified as a carrier

PURPOSE

When undergoing expanded carrier screening (ECS), couples are often screened sequentially to reduce need for a second individual's test. It is unknown how often partners of individuals found to be carriers complete the recommended testing with a sequential approach and what factors contribute to decision-making regarding partner testing. Additionally, the economic burden placed on individuals by ECS testing and its effect on partner testing has not been evaluated.

METHODS

In part 1, all individuals at a university-affiliated reproductive endocrinology and infertility practice identified to be carriers of a recessively inherited mutation using the Counsyl/Foresight ECS were included. Conditions were categorized by severity according to a previously described classification system. In part 2, all individuals who underwent ECS with a single test provider between September 1, 2013 and February 1, 2020 were contacted via email to complete a confidential and anonymized online survey.

RESULTS

In part 1, a total of 2061 patients were screened. 36.9% were carriers of one or more recessively inherited disorders. Twenty-seven percent of positively screened individuals did not have their partner screened. Carriers of a moderate condition had a trend towards a reduced odds for having their partner screened compared to a profound condition (OR 0.36, 95% CI 0.12-1.05, p = 0.06). Number of conditions was not predictive of subsequent partner screening (OR 0.95, 95% CI 0.72-1.25, p = 0.72). In part 2, the cost of ECS was not covered by insurance for 54.5% (103/189) and most paid over $300 out-of-pocket for testing (47.6%). The most common reason for not completing partner testing was that the results would not alter their course when seeking conception (33.3%). 73.5% of patients knew that the largest benefit of ECS comes from knowing a partner's results as well as their own.

CONCLUSIONS

Not all carriers of recessively inherited disorders choose to undergo partner screening. Patients found to be carrier of more debilitating genetic disorders may be more likely to screen their reproductive partners. For many, ECS testing is not covered by insurance, and this test may impose a significant economic burden. For some patients, the results of ECS would not change what they would do when seeking conception. Providers should evaluate whether a patient's ECS result would change their treatment course prior to testing.

Current attitudes and preconceptions towards expanded carrier screening in the Eastern Chinese reproductive-aged population

PURPOSE

A growing number of Chinese individuals of reproductive age will face the choice of accepting or refusing expanded carrier screening (ECS). This study aimed to explore the awareness, wishes, and possible misconceptions of ECS among this population, as well as factors affecting their decision-making.

METHODS

Chinese reproductive-aged individuals in Eastern China who sought cell-free fetal DNA screening and peripheral blood karyotype were invited to complete a 31-item ECS survey by scanning a specific quick response code. We evaluated the relationship between awareness, attitudes, and intentions to participate in ECS, along with possible misconceptions.

RESULTS

Overall, 93.1% of participants intended to undergo ECS at their expenses, and 53.6% indicated they would pay less than 1000 CNY (approximately 145 USD) for the test. Around 96.5% of participants had misconceptions about ECS and genetic diseases. Participants whose first reaction was interest, who had prior awareness of the test, or who perceived benefits were more likely to intend to use ECS (p < 0.001). Participants with a bachelor's degree or above or with a household income over 150,000 CNY (approximately 21,700 USD) would be more likely to pay ≥ 1000 CNY (p < 0.05).

CONCLUSIONS

Our study indicates that overall, the Eastern Chinese reproductive-aged population has positive attitudes towards ECS, although there are some misconceptions about ECS and genetic disorders. Population-based ECS appears to be desired by the reproductive-aged people in Eastern China. Steps should be taken to offer ECS along with pre- and post-test education and genetic counseling to raise awareness and to reduce misconceptions.

Which types of conditions should be included in reproductive genetic carrier screening? Views of parents of children with a genetic condition

Reproductive genetic carrier screening identifies couples with an increased chance of having children with autosomal and X-linked recessive conditions. Initially only offered for single conditions to people with a high priori risk, carrier screening is becoming increasingly offered to individuals/couples in the general population for a wider range of genetic conditions. Despite advances in genomic testing technology and greater availability of carrier screening panels, there is no consensus around which types of conditions to include in carrier screening panels. This study sought to identify which types of conditions parents of children with a genetic condition believe should be included in carrier screening. Participants (n = 150) were recruited through Royal Children's Hospital (RCH) Melbourne outpatient clinics, the Genetic Support Network of Victoria (GSNV) and a databank of children with hearing loss (VicCHILD). This study found that the majority of participants support offering carrier screening for: neuromuscular conditions (n = 128/134, 95.5%), early fatal neurodegenerative conditions (n = 130/141, 92.2%), chronic multi-system disorders (n = 124/135, 91.9%), conditions which cause intellectual disability (n = 128/139, 92.1%) and treatable metabolic conditions (n = 120/138, 87.0%). Views towards the inclusion of non-syndromic hearing loss (n = 88/135, 65.2%) and preventable adult-onset conditions (n = 75/135, 55.6%) were more mixed. Most participants indicated that they would use reproductive options to avoid having a child with the more clinically severe conditions, but most would not do so for clinically milder conditions. A recurring association was observed between participants' views towards carrier screening and their lived experience of having a child with a genetic condition.

Beyond the "Jewish panel": the importance of offering expanded carrier screening to the Ashkenazi Jewish population

Objective

To assess whether or not the current American College of Obstetricians and Gynecologists (ACOG) recommendations regarding carrier screening are sufficiently robust in detecting mutations in the Ashkenazi Jewish (AJ) population.

Design

Cross-sectional study.

Setting

Outreach program at university community center.

Patient(s)

Self-identified Jewish students, 18–24 years of age, interested in genetic carrier testing.

Intervention(s)

Expanded carrier screening (ECS) with the use of a commercially available targeted genotyping panel including >700 mutations in 180 genes.

Main Outcome Measure(s)

Gene mutations found in this population were grouped into three categories based on ACOG’s 2017 committee opinion regarding carrier screening: category 1: the four commonly recommended genetic conditions known to be a risk for this population; category 2: 14 genetic disorders that should be considered for more comprehensive screening, including those of category 1; and category 3: the ECS panel, which includes category 2.

Result(s)

A total of 81 students underwent screening and 36 (44.4%) were ascertained to be carriers of at least one mutation. A total of 45 mutations were identified, as 8 students were carriers for more than one condition. If testing were limited to category 1, 84% of the mutations would not have been identified, and if limited to category 2, 55% of mutations would have gone undetected.

Conclusion(s)

Individuals of Ashkenazi Jewish descent are at significant risk for carrying a variety of single-gene mutations and therefore they should be offered panethnic ECS to increase the likelihood of detecting preventable disorders.

Autonomous decisions by couples in reproductive care

Background

Preconception Expanded Carrier Screening (ECS) is a genetic test offered to a general population or to couples who have no known risk of recessive and X-linked genetic diseases and are interested in becoming parents. A test may screen for carrier status of several autosomal recessive diseases at one go. Such a program has been piloted in the Netherlands and may become a reality in more European countries in the future. The ethical rationale for such tests is that they enhance reproductive autonomy. The dominant conception of autonomy is individual-based. However, at the clinic, people deciding on preconception ECS will be counselled together and are expected to make a joint decision, as a couple. The aim of the present study was to develop an understanding of autonomous decisions made by couples in the context of reproductive technologies in general and of preconception ECS in particular. Further, to shed light on what occurs in reproductive clinics and suggest concrete implications for healthcare professionals.

Main text

Based on the shift in emphasis from individual autonomy to relational autonomy, a notion of couple autonomy was suggested and some features of this concept were outlined. First, that both partners are individually autonomous and that the decision is reached through a communicative process. In this process each partner should feel free to express his or her concerns and preferences, so no one partner dominates the discussion. Further, there should be adequate time for the couple to negotiate possible differences and conclude that the decision is right for them. The final decision should be reached through consensus of both partners without coercion, manipulation or miscommunication. Through concrete examples, the suggested notion of couple autonomy was applied to diverse clinical situations.

Conclusions

A notion of couple autonomy can be fruitful for healthcare professionals by structuring their attention to and support of a couple who is required to make an autonomous joint decision concerning preconception ECS. A normative implication for healthcare staff is to allow the necessary time for decision-making and to promote a dialogue that can increase the power of the weaker part in a relationship.

Expanded genetic carrier screening in clinical practice: a current survey of patient impressions and attitudes

PURPOSE

Expanded genetic carrier screening (ECS) is an important part of gynecological practice and preconception planning. We evaluated the awareness and attitudes among women regarding ECS and factors that may influence decision-making in a family planning context.

METHODS

A 32-question survey in an academic university practice was given to 521 women who were either currently pregnant (n = 108), undergoing gynecologic care who were considering future fertility (n = 308), and considering or receiving fertility treatment (n = 105). Data are reported descriptively.

RESULTS

Forty-seven percent (n = 246) of patients were aware of ECS. Though most reported feeling positive or neutral towards ECS, 51% (n = 263) reported no desire for testing. Fifty-eight percent (n = 303) felt it beneficial to know their carrier status, and 55% (n = 257) said it was their responsibility to undergo testing. Those considering future fertility were found to have a more positive attitude towards ECS (51.4%) than those considering or receiving fertility treatment (34%). For positive carriers of a genetic disorder, 228 (49%) of patients would proceed with having their partner screened, 58 (13%) would undergo prenatal screening only and 12 (2.6%) would continue with vitro fertilization (IVF). Related to cost for ECS, 53.5% (n = 191) would be willing to pay at least $50-100 for testing, while 29% (n = 146) would not pay anything out of pocket.

CONCLUSIONS

Despite patients' beliefs that it would be beneficial and their responsibility to undergo carrier status testing, the majority reported no desire for ECS and many were unwilling to pay out of pocket. Further education is necessary to reconcile the gap between technology and patient decision-making.

Attitudes of the general population towards preconception expanded carrier screening for autosomal recessive disorders including inborn errors of metabolism

BACKGROUND

A substantial number of severely debilitating and often ultimately fatal inborn errors of metabolism (IEMs) still lack an effective disease-modifying treatment. Informing couples before a pregnancy about an increased risk of having a child with an inherited disorder is now feasible by preconception expanded carrier screening (ECS). While knowledge about carrier status enhances reproductive autonomy, it may also result in ethical dilemmas. The purpose of this study was to assess the attitudes of the general Dutch population towards preconception ECS and to investigate which factors influence these attitudes.

METHODS

Data collection was carried out in collaboration with a market research agency. In total, 1188 Dutch individuals of reproductive age (18-45 years) were invited by email to complete an online ECS questionnaire in 2016. Prior to the start of the questionnaire, a written explanation of the concepts of autosomal recessive (AR) inheritance, carrier status and ECS was presented.

RESULTS

The questionnaire was completed by 781 individuals (65.7%), of whom 31% indicated they would take an ECS test themselves. In addition, 55% agreed that ECS should be offered to all prospective parents. The most frequently selected argument in favor of ECS (47.2%) was that participants want to spare a child from a life with a severe hereditary disorder. The reason most often mentioned not to participate in ECS (48%) was that participants reported not having a hereditary disorder in the family. The majority preferred receiving individual test results above a couple-based disclosure method in which participants receive the carrier status results only when they are a carrier couple of the same disorder. Participants with religious beliefs were less likely to participate in ECS, whereas participants who were considering a (future) pregnancy were more likely to participate.

CONCLUSION

Our study demonstrates an overall positive attitude among participants of reproductive age in the general Dutch population towards preconception ECS. A striking misconception is that many of the participants believe that ECS is of interest only for those with a positive family history of one of the hereditary disorders. This finding emphasizes the importance of providing understandable, balanced information and education to the general public regarding the concepts of inheritance when presenting the option of carrier screening. Our results provide valuable insights that can be used in the debate about the responsible implementation of preconception ECS for AR disorders, including IEMs.

"A perfect society"- Swedish policymakers' ethical and social views on preconception expanded carrier screening

To improve healthcare policymaking, commentators have recommended the use of evidence, health technology assessment, priority setting, and public engagement in the process of policymaking. Preconception expanded carrier screening, according to the World Health Organization's definition, is a novel health technology and therefore warrants assessment, part of which involves evaluating ethical and social implications. We examined ten Swedish policymakers' perspectives on ethical and social aspects of preconception expanded screening through in-depth expert interviewing, using a semi-structured questionnaire. Respondents were affiliated to governmental and non-governmental institutions that directly influence healthcare policymaking in Sweden. The interviews were recorded, transcribed verbatim, and analyzed via inductive thematic analysis method, which generated seven themes and several subthemes. Policymakers harbored concerns regarding the economics, Swedish and international political respects, implementation procedures, and societal effects, which included long-term ones. Moreover, participants detailed the role of public engagement, research, and responsibility in regard to preconception expanded carrier screening implementation. Since this is a qualitative study, with a small non-random sample, the results may not be generalizable to all policymakers in Sweden. However, the results give a profound insight into the process and interpretative knowledge of experts, in the Swedish milieu and the extent of readiness of Sweden to implement a preconception expanded carrier screening program.

Expanded carrier screening: A current perspective

Prenatal carrier screening has expanded to include a large number of genes offered to all couples considering pregnancy or with an ongoing pregnancy. Expanded carrier screening refers to identification of carriers of single-gene disorders outside of traditional screening guidelines. Expanded carrier screening panels include numerous autosomal recessive and X-linked genetic conditions, including those with a very low carrier frequency, as well as those with mild or incompletely penetrant phenotype. Therefore, the clinical utility of these panels is still subject of debate. Priority should be given to carrier screening panels that include a comprehensive set of severe childhood-onset disorders. Psychosocial support and genetic couseling should be available prior to screening and for the return of positive results. Systems are needed to reduce the risk of misinterpreting results. Finally, attention should be paid on the impact of expanded carrier screening on health care organizations and burden of cost.

Expanded Carrier Screening

Prenatal carrier screening has expanded to include a larger number of genes and variants offered to all couples considering or with an ongoing pregnancy. Panethnic screening for cystic fibrosis and spinal muscular atrophy and screening for a limited number of conditions based on ethnicity are recommended by the American College of Obstetricians and Gynecologists. Residual risk calculations have become an obsolete part of posttest counseling when expanded carrier screening (ECS) is selected. The Perception of Uncertainties in Genome Sequencing scale offers a useful understanding of the pretest and posttest counseling concerns that should be considered as part of ECS implementation.

Expanded carrier screening: a current survey of physician utilization and attitudes

PURPOSE

Expanded carrier screening (ECS) is an available component of preconception and prenatal care. There is complexity around offering, administering, and following-up test results. The goal of this study is to evaluate current physicians' utilization and attitudes towards ECS in current practice.

METHODS

This was a prospective qualitative survey study. A 32-question electronic survey was distributed during a 1-year period to obstetricians-gynecologists who were identified using a Qualtrics listserv database.

RESULTS

While more than 90% of physicians offered ethnic-based carrier screening (CS), ECS was offered significantly less (2010, 20.6%, and 2016, 27.1%). Physicians who were not fellowship-trained in reproductive endocrinology and infertility (REI) preferred ethnic-based carrier screening (95.9 vs 16.8%; P < 0.001). REI subspecialists were more likely to offer ECS (80%) compared to 70% of maternal fetal medicine physicians (MFM). Physicians were comfortable discussing negative results (53.6%) compared to positive results (48.4%). Most physicians (56%) believed that ECS should not be offered until the significance of each disease is understood; 52% believed that testing should be restricted to those conditions important to couples; while 26% felt that testing should be done regardless of the clinical significance.

CONCLUSIONS

Discussion and application of ECS has increased in clinical practice. However, lack of comfort with counseling and varying beliefs surrounding ECS continue to hinder its utilization. Further education and training programs, and subsequent evaluation are warranted.

Prenatal genetic carrier screening in the genomic age

The Society for Maternal-Fetal Medicine, American College of Obstetricians and Gynecologists (ACOG), and American College of Medical Genetics and Genomics (ACMG) held a workshop entitled "Prenatal Genetic Testing" on January 25, 2017 to address several questions arising from the increasing implementation of preconception and prenatal expanded carrier screening (ECS). ECS allows for identification of a greater number of genetic sequencing changes (not all of which cause disease) and simultaneous testing for an increased number of genetic conditions without limitation to specific ethnic groups. The workshop participants reached consensus on the following: ethnicity based testing cannot be completely abandoned in favor of panethnic ECS; the specific approach to screening should be a patient's choice and not driven solely by provider preference; organizations should work to develop a framework for vetting conditions that should be reported on ECS panels; compared with prenatal screening, preconception screening is ideal and, at this time, due to the costs and the need for timeliness associated with prenatal screening posttest counseling and testing, that when ECS is offered it should be presented as a preconception option; preconception and prenatal panels should be identical across the spectrum of patients, including those undergoing assisted reproduction; adult-onset conditions should not be included on ECS panels; partners should be offered next-generation sequencing to identify rare variants when the first partner screened is determined to be a carrier; re-screening in subsequent pregnancies is not indicated, despite the potential for expansion of carrier screening conditions and variants; and more education about ECS for providers and patients is necessary to implement prenatal carrier screening in a responsible way.

Clinical Utility of Expanded Carrier Screening: Reproductive Behaviors of At-Risk Couples

Expanded carrier screening (ECS) analyzes dozens or hundreds of recessive genes to determine reproductive risk. Data on the clinical utility of screening conditions beyond professional guidelines are scarce. Individuals underwent ECS for up to 110 genes. Five-hundred thirty-seven at-risk couples (ARC), those in which both partners carry the same recessive disease, were invited to participate in a retrospective IRB-approved survey of their reproductive decision making after receiving ECS results. Sixty-four eligible ARC completed the survey. Of 45 respondents screened preconceptionally, 62% (n = 28) planned IVF with PGD or prenatal diagnosis (PNDx) in future pregnancies. Twenty-nine percent (n = 13) were not planning to alter reproductive decisions. The remaining 9% (n = 4) of responses were unclear. Of 19 pregnant respondents, 42% (n = 8) elected PNDx, 11% (n = 2) planned amniocentesis but miscarried, and 47% (n = 9) considered the condition insufficiently severe to warrant invasive testing. Of the 8 pregnancies that underwent PNDx, 5 were unaffected and 3 were affected. Two of 3 affected pregnancies were terminated. Disease severity was found to have significant association (p = 0.000145) with changes in decision making, whereas guideline status of diseases, controlled for severity, was not (p = 0.284). Most ARC altered reproductive planning, demonstrating the clinical utility of ECS. Severity of conditions factored into decision making.

Carrier screening for single gene disorders

Screening for genetic disorders began in 1963 with the initiation of newborn screening for phenylketonuria. Advances in molecular technology have made both newborn screening for newborns affected with serious disorders, and carrier screening of individuals at risk for offspring with genetic disorders, more complex and more widely available. Carrier screening today can be performed secondary to family history-based screening, ethnic-based screening, and expanded carrier screening (ECS). ECS is panel-based screening, which analyzes carrier status for hundreds of genetic disorders irrespective of patient race or ethnicity. In this article, we review the historical and current aspects of carrier screening for single gene disorders, including future research directions.

Expanded carrier screening and preimplantation genetic diagnosis in a couple who delivered a baby affected with congenital factor VII deficiency

Background

Preimplantation genetic diagnosis (PGD) is a powerful tool for preventing the transmission of Mendelian disorders from generation to generation. However, PGD only can identify monogenically inherited diseases, but not other potential monogenic pathologies. We aimed to use PGD to deliver a healthy baby without congenital FVII deficiency or other common Mendelian diseases in a couple in which both individuals carried a deleterious mutation in the F7 gene.

Methods

After both members of the couple were confirmed to be carriers of the F7 gene mutation by Sanger sequencing, expanded carrier screening (ECS) for 623 recessive inheritance diseases was performed to detect pathological mutations in other genes. PGD and preimplantational genetic screening (PGS) were employed to exclude monogenic disorders and aneuploidy for their embryos.

Results

ECS using targeted capture sequencing technology revealed that the couple carried the heterozygous disease-causative mutations c.3659C > T (p.Thr1220Ile) and c.3209G > A (p.Arg1070Gln) in the CFTR gene. After PGD and PGS, one of their embryos that was free of congenital FVII deficiency, cystic fibrosis (CF) and aneuploidy was transferred, resulting in the birth of a healthy 3200 g male infant.

Conclusion

We successfully implemented PGD for congenital FVII deficiency and PGD after ECS to exclude CF for the first time to the best of our knowledge. Our work significantly improved the reproductive outcome for the couple and provides a clear example of the use of ECS combined with PGD to avoid the delivery of offspring affected not only by identified monogenically inherited diseases but also by other potential monogenic pathologies and aneuploidy.

Recent developments in genetics and medically assisted reproduction: from research to clinical applications

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Expanded carrier screening in gamete donors of Venezuela

OBJECTIVE

To discuss the implications of expanded genetic carrier screening for preconception purposes based on our practice.

METHODS

One hundred and forty-three potential gamete donors aged 20-32 years old (µ=24, 127 females and 16 males), signed informed consent forms and were selected according to the REDLARA guidelines. Blood or saliva samples were examined by one of these genetic carrier screening methods: Genzyme screening for Cystic Fibrosis (CF), Fragile X and Spinal Muscular Atrophy (SMA); Counsyl Universal panel or Recombine Carrier Map.

RESULTS

Genotyping results for all donors were analyzed; 41% (58/143) of donors were identified as carriers for at least one condition. We found a carrier frequency of 1/24 for CF, 1/72 for SMA and 0/120 for Fragile X syndrome. Among the high-impact most prevalent conditions in our study (Carrier Map group) were: 21-Hydroxilase-Deficient Congenital Nonclassical Adrenal Hyperplasia (1/8), Factor V deficiency (1/12), Hemochromatosis: Type 1: HFE Related (1/12), Short Chain Acyl-CoA (1/14) and MTHFR deficiency 1/3 (39%).

CONCLUSIONS

The rate of gamete donors identified as carriers of at least one condition was 41%, which supports the offering of expanded carrier screening to our population. Studies in Latin American populations could help customize screening panels. The ART patient population has a unique opportunity to be offered expanded carrier screening and appropriate counseling, to make its best-informed decisions.

Pre- and post-testing counseling considerations for the provision of expanded carrier screening: exploration of European geneticists' views

Background

Carrier screening is generally performed with the aim of identifying healthy couples at risk of having a child affected with a monogenic disorder to provide them with reproductive options. Expanded carrier screening (ECS), which provides the opportunity for multiple conditions to be screened in one test, offers a more cost-effective and comprehensive option than screening for single disorders. However, implementation of ECS at a population level would have implications for genetic counseling practice.

Methods

We conducted semi-structured interviews with sixteen European clinical and molecular geneticists with expertise in carrier screening to explore their views on the implementation of ECS in the clinical setting.

Results

Using inductive content analysis, we identified content categories relevant to the pre- and post-test settings. Participants believed ECS would ideally be targeted at couples before pregnancy. There was some disagreement regarding the acceptability of performing ECS in individuals, with several participants actively opposing individual-based screening. In addition, participants discussed the importance of ensuring informed and voluntary participation in ECS, recommending measures to minimize external pressure on prospective parents to undergo testing. A need for adequate counseling to foster informed, autonomous reproductive decision-making and provide support for couples found to be at risk was emphasized.

Conclusions

Practical challenges in optimizing pre-test education and post-test counseling should not be underestimated and they should be carefully addressed before implementing ECS in the clinical setting.

Experiences among Women with Positive Prenatal Expanded Carrier Screening Results

The offering and acceptance of expanded carrier screening is increasing among pregnant women including women without an increased risk based on race, ethnicity or family history. The chances of a positive screening test have been reported to be as high as 24 % when multiple conditions are screened. Yet, little is known about the way these tests are offered and how patients are affected by a positive test result. To explore this area of genetic testing, interviews (n = 17) were conducted among women who received positive expanded carrier results in the context of obstetric care. A content analysis was conducted on the transcript data from the interviews. Outcomes of this research suggest that educational interventions are needed to improve maternal understanding of positive carrier screening results. Most of the participants in this study confused the results with other prenatal screening test options. In addition, the way the results were discussed varied greatly, and influenced participants' thoughts about reproductive decisions that led to a range of emotional uncertainty. Our data suggests that genetic counseling improved participants' understanding of positive results. More research is needed to further understand if our results are consistent within a larger, more diverse sample, and to explore how to best provide education about expanded carrier screening.

Genetic Counselors' Perspectives and Practices Regarding Expanded Carrier Screening after Initial Clinical Availability

Expanded carrier screening (ECS), introduced in 2009, identifies carriers for dozens or hundreds of recessive diseases. At the time of its introduction into clinical use, perspectives of the genetic counseling community regarding ECS were unknown. We conducted a survey in early 2012 of GCs and report the results here. They represent a snapshot of opinions and usage at that time, providing a baseline for comparison as the technology continues to evolve and as usage increases. The survey assessed personal perspectives, opinions on clinical implementation and clinical utilization of ECS. The sample included 337 GCs of varying clinical fields, of whom 150 reported practicing in reproductive settings. Our findings demonstrate that, at the time, GCs indicated general agreement with ECS as a concept - for example, most GCs agreed that carrier screening should address diseases outside of current guidelines and also indicated personal interest in electing ECS. There were also disagreements or concerns expressed regarding appropriate pre- and post-test counseling (e.g., the content and delivery mode of adequate informed consent) and practical implementation (e.g., the amount of time available for follow-up care). This was the first quantitative study of a large number of GCs and it revealed initial overall support for ECS among the GC profession. The authors plan to re-administer a similar survey, which may reveal changes in opinions and/or utilization over time. A follow up survey would also allow further exploration of questions uncovered by these data.