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.

[Cystic fibrosis carrier screening: a Health technology assessment.] / Lo screening del portatore di fibrosi cistica: una valutazione di Health technology assessment.

This project of Health technology assessment was aimed at defining the impacts of offering a cystic fibrosis (CF) carrier screening to the general population, compared to the current situation, where the test is offered to individuals at high-risk to give birth to a child with CF. Results revealed: i) a lack of robust and updated data; ii) a return on investment up to six years from the screening's introduction, despite important economic and organizational efforts; iii) a general positive attitude of healthcare professionals, people with CF, families and general population; iv) possible issues related to the social impact.

Preconception or prenatal acceptance of SMN1 gene carrier screening and carrier rate of spinal muscular atrophy: a retrospective study in 18,818 reproductive age women in Wuhan area of China.

OBJECTIVE: Spinal muscular atrophy (SMA) is an autosomal recessive disorder mainly affecting the neuromuscular system, which seriously threatens the life and health of patients. But few studies have reported the acceptance rate of SMA gene screening and SMA carrier rate in China. The present study aimed to clarify the two issues in China through a retrospective analysis of 18,818 reproductive age women in Wuhan area of China. METHODS: The copy number (CN) of exons 7 and 8 in survival motor neuron 1 (SMN1) gene was detected by real-time quantitative PCR, and the results were verified by multiplex ligation-dependent probe amplification. RESULTS: Carrier screening was offered to 44,953 women of childbearing age in our medical center from March, 2018, to February, 2022, of whom 18,818 were enrolled in the program. A total of 336 women were identified as carriers (1.73%; 326/18,808; without fertility history of the children with SMA). Among 18,818 reproductive age women, 286 spouses (85.12%; 286/336) were successfully recalled for screening. The results showed 17 couples at high risk of having children with SMA, of whom prenatal diagnosis was implemented in 11, and 6 fetuses were identified with SMA. All the 5 pregnant women bearing the 6 SMA fetuses chose to terminate the pregnancy by artificial abortion. CONCLUSION: Reproductive age women and their spouses in Wuhan area showed a positive attitude toward general screening for SMA carriers. Given the high early mortality of children with SMA, screening for SMA carriers in women of reproductive age is necessary and feasible.

Ethnically unique disease burden and limitations of current expanded carrier screening panels.

OBJECTIVES: The purpose of the study is to identify the recessive diseases currently affecting real-world pediatric patients in Taiwan, and whether current extended carrier screening panels have the coverage and detective power to identify the pathogenic variants in the carrier parents. METHODS: A total of 132 trio-samples were collected from May 2017 to March 2022. The participants were parents of pediatric intensive care unit patients who were critically ill or infants with abnormal newborn screening results. A retrospective carrier screening scheme was applied to analyze only the carrier status of pathogenic or likely pathogenic recessive variants resulting in diseases in their children. The recessive disorders diagnosed in our cohort were compared with the gene content in commercial panels. RESULTS: Mutations in COQ4, PEX1, OTC, and IKBKG were the most frequently identified. In the parents of 44 children with confirmed diagnoses of recessive diseases, 47 (53.40%) screened positive for being the carriers of the same recessive disorders diagnosed in their children. The commercial panels covered 35.13% to 54.05% of the disorders diagnosed in this cohort. CONCLUSION: Clinicians and genetic counselors should be aware of the limitations of current extended carrier screening and interpret negative screening results with caution. Future panels should also consider genes with ethnically unique mutations such as pathogenic variants of the COQ4 gene in the East Asian population.

Effectiveness of preconceptional and prenatal cystic fibrosis carrier screening: a systematic review

BACKGROUND: genetic testing for cystic fibrosis (CF) has been offered to people with higher risk of being carrier. OBJECTIVES: to assess the effectiveness of population-based CF carrier screening for adults of reproductive age and its optimal organizational features. DESIGN: systematic review. SETTING AND PARTICIPANTS: MedLine, Embase, Cochrane Library, CINAHL and LILACS (1990-2022) were searched to retrieve primary and secondary studies on adults (16 years and older), with no clinical indication or genetic risk, eligible for genetic testing for CF carrier status. MAIN OUTCOMES MEASURES: attitude to screening, uptake of screening offered, informed reproductive choices. RESULTS: a total of 3,326 records were screened and 292 potentially eligible full-text publications assessed. The review included 71 publications, corresponding to 3 reviews, 40 cohort studies (11 comparative, 29 single-arm), and 6 model studies, published between 1992 and 2021 (median 1998). Only one study compared screening or no screening. This study suggested an association between carrier screening and a lower incidence of CF. Comparative studies examined different approaches for invitation and testing, i.e., settings, target population (individuals/couples, prenatal/preconceptional), how invitations are organized (primary care/maternal hospitals), and format and content of the pre-test information. However, no firm conclusions can be drawn on the impact of these features on informed reproductive choices, uptake, and attitude, because of the limitations of the evidence collected. CONCLUSIONS: the broad heterogeneity of the studies, methodological weaknesses, and the limited transferability of the results mean there is still uncertainty about the effectiveness of preconceptional and prenatal CF carrier screening in the general population.

Improvement in cystic fibrosis newborn screening program outcomes with genetic counseling via telemedicine.

INTRODUCTION: The Cystic Fibrosis Foundation (CF Foundation) recommends the provision of genetic counseling (GC) to help educate families and decrease anxiety around the cystic fibrosis (CF) newborn screening process. Unfortunately, access to genetic counselors is limited, especially for CF trained genetic counselors. We hypothesized that the GC process for families could be improved by utilizing telemedicine to leverage the availability of two dedicated, CF trained genetic counselors to provide access to GC for several CF centers. In addition, we hoped to demonstrate that use of trained CF genetic counselors, delivering GC via telemedicine at the time of sweat testing, would provide families with understanding of CF genetics as well as result in high satisfaction with the newborn screening process. METHODS: GC was provided by CF trained genetic counselors via telemedicine at the time of sweat testing. Following the counseling session, families were administered an anonymous written survey to evaluate their impression of the services provided. A subset of 50 families was recruited for an assessment of gained knowledge regarding CF genetics using the Ciske knowledge inventory. Using χ2  analysis, Ciske knowledge inventory data from our telemedicine GC families was compared to counseled and uncounseled Ciske historical controls. Lastly, in-depth interviews about the newborn screening process for CF were performed with 10 families and interviews were coded for emerging themes. RESULTS: During the 4 years of the study, 250 patients received GC. Overall comfort with the counseling rated 4.77 out of 5 using a Likert scale. After counseling by telemedicine, parents demonstrated improved understanding of the genetic implications of an abnormal CF newborn screen for their family, with 100% of families understanding that their child was a carrier for CF as compared to 97.2% of counseled (p = .023) and 78.5% of uncounseled (p = .0007) from Ciske historical controls. The study group also showed improvement in understanding of both parents possibly being carriers, with an 87.7% correct response rate compared to a 37.0% correct response rate in the counseled group (p < .0001) and a 35.4% correct response rate in the non-counseled group (p < .0001) from Ciske historical controls. Subgroup analysis at one site showed a significant increase in the number of infants with completed sweat tests from previous years (49% in 2013 vs. 80% in 2017 during the study, p < .0001). CONCLUSIONS: GC by telemedicine was well received by families and demonstrated improved family knowledge acquisition and understanding of CF as it related to risks for their child as well as identification of risks for other family members. Furthermore, in addition to an increase is those receiving GC, a subgroup analysis demonstrated a significant increase in the number of infants receiving sweat tests. This study demonstrates that GC via telemedicine for CF is feasible and demonstrates improvement in parent understanding of CF genetics. Furthermore, this method can be implemented effectively across a wide geographical area with a limited number of CF trained genetic counselors to improve access to care for patients and families.

Current State of Dor Yeshorim, Expanded Carrier, and Newborn Screening: Benefits and Limitations.

ABSTRACT: Availability and accessibility of preconception and prenatal genetic carrier and newborn biochemical and genetic screening have grown exponentially over the past 2 decades and as such, it is challenging for clinicians to keep pace. Although genetic counseling or genetic consultation should be offered to all expectant and new parents for prenatal screening decisions and positive results, benefits and limitations of these tests and results must be known and familiar to perinatal and pediatric clinicians. A brief historical overview of Dor Yeshorim, preconception and prenatal expanded carrier, and newborn screening is presented, followed by discussion about the conditions screened and considerations surrounding the benefits and limitations of these tests in the practice setting.

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: In this descriptive retrospective cohort study from 2018 to 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. Of these 643 women, 462 were heterozygotes and 326 of 462 had undergone counseling. Two hundred twenty-two of 462 partners obtained testing, with a median of 32 days from patient to partner result. Approximately 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.

Detection of male 2+0 and 1+0 carriers for spinal muscular atrophy by digital PCR.

Spinal muscular atrophy (SMA) is an autosomal recessive disease with a high carrier frequency. While current screening methods can identify 1+0 carriers, detecting 2+0 genotypes remains challenging, highlighting the need for additional research. Herein, we applied Digital Polymerase Chain Reaction (dPCR) to develop a novel approach for the detection of male carriers (DMC), especially for those with a 2+0 genotype. The clinical utility of DMC was evaluated in 39 semen samples. Multiple ligation-dependent probe amplification (MLPA) and pedigree analysis were performed on genomic DNA from 111 males and their family members. DMC identified 1+1, 2+1, and 1+0 genotypes in 21, 1, and 8 subjects. Importantly, seven men were identified as 2+0 carriers, while two men were excluded from the 2+0 carrier status. The results of DMC were consistent with those of MLPA and pedigree analysis. DMC provides an inexpensive and accurate method for determining the 2+0 and 1+0 genotypes.

Pregnant Latinas' perspectives on pursuing expanded carrier screening: "It is better to know than not".

With the advance of genetic technologies, the use of expanded carrier screening (ECS) in the prenatal setting is growing. ECS tests for a wide range of inherited genetic disorders regardless of racial/ethnic background and family history. Latinxs are an important ECS stakeholder group as they are the largest minority group with the highest fertility rate in the United States. Yet, the Latinx population has, to date, been underrepresented and understudied in genetics/genomics research. We conducted a study to explore the knowledge and perspectives of pregnant Latinas regarding ECS in which descriptive statistics and content analysis were used to analyze the data. Thirty-two pregnant Latinas - mostly of low educational levels (no education beyond high school) and with less than $20,000 annual household income living in rural areas were surveyed, provided with education about ECS, and interviewed. Participants were found to possess limited knowledge about ECS prior to being interviewed. Most (68.8%), however, expressed interest in pursuing ECS following the educational component that explained ECS. Their interest was mainly driven by the desire to know their baby's chance of developing a genetic disorder, the low risk of ECS procedures for both pregnant Latinas and their fetus, and the opportunity to better prepare for raising a child with a genetic condition. Our findings contribute to the limited research in the genetics/genomics field by providing in-depth insights into the perspectives of pregnant Latinas regarding ECS. Obstetric providers and genetic counselors should provide culturally appropriate education and counseling to empower pregnant Latinas to make informed decisions about the use of ECS.

Experiences of nonpregnant couples after receiving reproductive genetic carrier screening results in Belgium.

Reproductive genetic carrier screening (RGCS) allows for the identification of couples who have an increased likelihood of conceiving a child with a particular autosomal recessive or X-linked condition. The aim of this study was to assess the level of satisfaction, anxiety, knowledge retention, psychosocial and counseling-related aspects among couples who chose to have RGCS. Participants were initially informed about their screening results by telephone. After obtaining a written report of test results, participants were asked to complete an individual self-administered questionnaire. All participants (n = 67) felt they had enough information to make an informed choice. None of the participants regretted their choice to have RGCS. Test results were most often shared with parents (61%) or siblings (37%). Our findings demonstrate that the information/counseling and reporting strategy that was used in the context of this study led to high participant satisfaction, an increase in knowledge over time and favorable psychosocial and counseling-related outcomes.

Genetic counseling and carrier screening in candidates for gamete donation at a Portuguese center.

OBJECTIVE: Genetic counseling and carrier screening are part of the gamete donation process by healthy individuals. We aim to review the findings of genetic counseling and carrier screening of a cohort of candidates at our public gametes bank. METHODS: Thirty-four male and 64 female candidates had genetic counseling with a medical geneticist before donation. Of these, one female candidate voluntarily dropped-out. Thirty-four males and 63 females performed karyotype and screening for the more common pathogenic variants for CFTR-related cystic fibrosis and spinal muscular atrophy (SMN1) in the Portuguese population. In addition, all females also performed Fragile X expansion screening (FMR1). Thirty candidates with known or assumed African ancestry performed hemoglobinopathies screening. RESULTS: Six candidates were definitely or temporarily withheld from the donation process given their family or personal history that required further investigation. Of 97 candidates tested, 16.5% presented anomalous laboratory results (16/97): ten candidates were carriers for an autosomal recessive disorder - cystic fibrosis (5/97), sickle cell anemia (3/30), and spinal muscular atrophy (2/97). One female was an FMR1 pre-mutation carrier (1/63). One female candidate presented with triple X mosaicism: 47,XXX[2]/46,XX[50]. Two candidates presented with chromosomal instability of unknown origin. In one candidate, a mosaic for the Philadelphia chromosome was detected, revealing the diagnosis of chronic myeloid leukemia. CONCLUSIONS: From a cohort of 97 candidates, 21.7% had a family/personal history or an anomalous laboratory result that required additional genetic counseling, stressing the importance of performing pre-donation genetic counseling in this population.

Incidental molecular diagnoses and heterozygous risk alleles in a carrier screening cohort.

PURPOSE: Expanded pan-ethnic carrier screening is an effective tool for the management of reproductive risk. However, growth in the number of conditions screened, in combination with increasingly more comprehensive test methodologies, can lead to the detection of genetic findings that may affect the health of the tested individual. The objective of this study was to investigate the frequency of pathogenic genotypes in a presumed healthy carrier screening cohort to facilitate broader discussions regarding disclosure of genetic information from carrier screening. METHODS: A retrospective analysis of 73,755 targeted carrier screens was performed to identify individuals with pathogenic genotypes and heterozygous risk alleles. RESULTS: In this study, we identified 79 individuals (0.11%) with pathogenic genotypes associated with moderate to profound autosomal recessive or X-linked conditions. In addition, 10 cases had chromosome X dosage abnormalities suggestive of a sex chromosome abnormality. Heterozygote risk alleles represented the majority of ancillary findings in this cohort, including 280 female carriers of FMR1 premutation alleles, 15 heterozygous females with pathogenic DMD variants, and 174 heterozygotes with pathogenic variants in genes that may confer increased risk for somatic malignancies in the heterozygous state. CONCLUSION: These data suggest that nearly 1% of individuals undergoing carrier screening will have a finding that may require clinical evaluation or surveillance.

A Cross-Sectional Study of the Marital Attitudes of Pregnant Women at Risk for Cystic Fibrosis and Psychological Impact of Prenatal Screening.

Cystic fibrosis (CF) is one of the most frequent genetic disorders in those with Northern European ancestry. Prenatal testing for cystic fibrosis may be used to plan and prepare for the birth of a child with the disease or to determine whether to terminate the pregnancy. The accessibility of prenatal detection for women with a high genetic risk of delivering a child with cystic fibrosis is determined by CF carriers and those affected by the disease. Moreover, prenatal testing for CF is mainly dependent on invasive diagnostic tests that can influence the mental health of the pregnant woman, and it is assumed that the birth of a CF child will have a serious influence on the couple's subsequent family planning and marital behavior. The purpose of this research was to examine the marital attitudes of women at risk for cystic fibrosis and the psychological effect of screening for CF among pregnant women. The study followed a cross-sectional design with five questionnaires comprising Prenatal Attachment Interview (PAI), Maternal Antenatal Attachment Scale (MAAS), Pregnancy-Related Anxiety Questionnaire (PRAQ-R2), the Prenatal Psychosocial Profile (PPP), and the Marital Intimacy Questionnaire (MIQ). A total of 84 pregnant women were included in the "carriers" group for CFTR and 91 in the "non-carrier" group. CFTR-carrier mothers were likely to be more affectionate to the fetus, with better maternal-fetal quality and intensity of attachment. The same group of pregnant women was less scared of giving birth or worried about bearing a physically or mentally handicapped child compared to women who were expecting the prenatal diagnosis test for being at risk of delivering a newborn with malformations. CFTR-carrier pregnant women did not score significantly different results in the Prenatal Psychosocial Profile regarding stress levels, social support, and self-esteem. It was also found that intimacy and consensus problems inside the marriage were significantly more often experienced by CFTR carriers. Based on the current findings, it is likely that CFTR-carrier mothers have a better perception of the possible pregnancy outcomes by knowing their abnormal gene carrier status. Therefore, the psychological impact of invasive diagnostic tests is lower in this category compared with those who are unaware of the possible pregnancy outcomes. However, we promote a future analysis for pregnant women with moderate risk of giving birth to a child with single-gene mutations such as cystic fibrosis or other congenital malformations that undergo noninvasive prenatal diagnosis tests, as they become more accurate and might cause lower pre-diagnosis stress levels.

Reasons affecting the uptake of reproductive genetic carrier screening among nonpregnant reproductive-aged women in Flanders (Belgium).

Reproductive genetic carrier screening (RGCS) allows to identify couples who have an increased likelihood of conceiving a child affected with an autosomal recessive or X-linked monogenic condition. Multiple studies have reported on a wide and fragmented set of reasons to accept or decline RGCS. Only a few studies have been performed to assess the uptake of RGCS. Nonpregnant women visiting their gynecologist were invited to complete a questionnaire assessing perceived susceptibility, the acceptability of offering RGCS, attitudes, the intention to participate in RGCS, reasons to accept or decline RGCS, and sociodemographic characteristics. Women who showed the intention to have RGCS were asked to consider a free RGCS offer. Most women (n = 127) were between 25 and 34 years old (60%), in a relationship (91%), and wanted to have children (65%). Study participants had positive attitudes towards RGCS and the intention to consider RGCS in the future. Reasons to accept RGCS were being able to share genetic information with children or relatives (n = 104/127, 82%), to prevent the birth of a child affected with a hereditary condition (n = 103/127, 81%), and/or to know the chance of conceiving a child with a hereditary condition (n = 102/127, 80%). Reasons for declining RGCS were the possible concerns that could arise when receiving test results (n = 27/127, 21%), having no family history of hereditary disorders (n = 19/127, 15%), and not wanting to take action based on test results (n = 13/127, 10%). Among test intenders that met the inclusion criteria, 53% decided to participate in RGCS together with their male reproductive partner. More in-depth research on the decision-making process behind the choice to accept or decline an RGCS offer would be highly valuable to make sure couples are making informed reproductive choices.

Pathogenic variant-based preconception carrier screening in the Israeli Jewish population.

Preconception carrier screening allows identification of couples at risk to have offspring with autosomal recessive and X-linked disorders. In a current multiethnic world, screening based on self-reported ancestry has limitations. Here we describe the findings of a comprehensive pan-ethnic variant-based carrier screening, using the Israeli Jewish population as a model. The cohort included 1696 individuals (848 couples) tested with the 'MyScreen' multigene panel. The panel covers 1206 variants spanning 385 genes, known in different Jewish ethnicities and local Arab, Druze and Bedouin populations. Out of these, 205 variants in 143 genes are Jewish founder variants. We identified 859 (50.6%), carriers of at least one variant in 151 genes. Importantly, 569 (66.2%) of carriers could be missed by the current Israeli screening program. In total, 1:40 (2.5%) of carrier couples were identified by the 'MyScreen' panel, compared with 1:144 (0.7%) found by the ethnicity-based screening. Surprisingly, 90 individuals (10.5%) were carriers of variants "unexpected" for their reported origin, and 16 variants were previously unreported in Jewish patients. Our results support the advantages of variant-based comprehensive carrier screening for detection of carriers and at-risk couples in a diverse population with many founder disease-causing variants.

Current Updates on Expanded Carrier Screening: New Insights in the Omics Era.

Genetic carrier screening has been successfully used over the last decades to identify individuals at risk of transmitting specific DNA variants to their newborns, thus having an affected child. Traditional testing has been offered based on familial and/or ethnic backgrounds. The development of high-throughput technologies, such as next-generations sequencing, able to allow the study of large genomic regions in a time and cost-affordable way, has moved carrier screening toward a more comprehensive and extensive approach, i.e., expanded carrier screening (ECS). ECS simultaneously analyses several disease-related genes and better estimates individuals' carrier status. Indeed, it is not influenced by ethnicity and is not limited to a subset of mutations that may arise from poor information in some populations. Moreover, if couples carry out ECS before conceiving a baby, it allows them to obtain a complete estimation of their genetic risk and the possibility to make an informed decision regarding their reproductive life. Despite these advantages, some weakness still exists regarding, for example, the number of genes and the kind of diseases to be analyzed and the interpretation and communication of the obtained results. Once these points are fixed, it is expectable that ECS will become an ever more frequent practice in clinical settings.

Expanded carrier screening in the United States: A systematic evidence review exploring client and provider experiences.

The aim of carrier screening is to identify prospective parents at risk of having a pregnancy affected with an autosomal recessive or X-linked disorder. Though minimal guideline-based screening is available, expanded carrier screening (ECS) is quickly becoming a feasible option for the general population due to its growing availability and affordability. However, the impact of ECS on clients and providers remains relatively unexplored. We performed a systematic evidence review to identify publications describing client-, provider-, and test-related outcomes. We searched several biomedical databases for articles published between January 1, 2003 and May 31, 2021. Studies were eligible for inclusion if they described genetic counseling and/or genetic testing for carrier screening (minimal guideline-based or ECS) in a prenatal or preconception setting in the United States. Title and abstract screening were performed using the Raayan web application or customized Google Forms. Full-text review and data extraction of included articles were performed using custom Google Forms. Two researchers performed a multistep selection process independently for validation purposes. Of 5413 unique articles screened, 36 studies were included with several studies contributing to multiple outcomes. Twenty described outcomes relating to patients/clients, 10 described provider-based outcomes, and 16 described test-based outcomes. Findings suggest that client and provider perceptions of ECS and minimal guideline-based carrier screening are multifaceted. Though clients have expressed desire for ECS, clinical uptake and impact on reproductive decision-making varies. Additionally, though genetic counselors seem to be comfortable with ECS, most other reproductive care providers seem to prefer minimal guideline or ancestry-based screening due to perceived barriers, such as time needed for ECS results disclosure and follow-up, as well as the desire to have panels set by professional societies/recommendations. There are limitations within the gathered literature, leading to potential uncertainty in the generalizability of our review. We outline several recommendations for future studies, including the need to examine variant interpretation and use of next-generation sequencing.

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.

Carrier screening in the Mexican Jewish community using a pan-ethnic expanded carrier screening NGS panel.

PURPOSE: The Mexican Jewish community (MJC) is a previously uncharacterized, genetically isolated group composed of Ashkenazi and Sephardi-Mizrahi Jews who migrated in the early 1900s. We aimed to determine the heterozygote frequency of disease-causing variants in 302 genes in this population. METHODS: We conducted a cross-sectional study of the MJC involving individuals representing Ashkenazi Jews, Sephardi-Mizrahi Jews, or mixed-ancestry Jews. We offered saliva-based preconception pan-ethnic expanded carrier screening, which examined 302 genes. We analyzed heterozygote frequencies of pathogenic/likely pathogenic variants and compared them with those in the Genome Aggregation Database (gnomAD). RESULTS: We recruited 208 participants. The carrier screening results showed that 72.1% were heterozygous for at least 1 severe disease-causing variant in 1 of the genes analyzed. The most common genes with severe disease-causing variants were CFTR (16.8% of participants), MEFV (11.5%), WNT10A (6.7%), and GBA (6.7%). The allele frequencies were compared with those in the gnomAD; 85% of variant frequencies were statistically different from those found in gnomAD (P <.05). Finally, 6% of couples were at risk of having a child with a severe disorder. CONCLUSION: The heterozygote frequency of at least 1 severe disease-causing variant in the MJC was 72.1%. The use of carrier screening in the MJC and other understudied populations could help parents make more informed decisions.