Australian public perspectives on genomic newborn screening: which conditions should be included?

BACKGROUND: Implementing genomic sequencing into newborn screening programs allows for significant expansion in the number and scope of conditions detected. We sought to explore public preferences and perspectives on which conditions to include in genomic newborn screening (gNBS). METHODS: We recruited English-speaking members of the Australian public over 18 years of age, using social media, and invited them to participate in online focus groups. RESULTS: Seventy-five members of the public aged 23-72 participated in one of fifteen focus groups. Participants agreed that if prioritisation of conditions was necessary, childhood-onset conditions were more important to include than later-onset conditions. Despite the purpose of the focus groups being to elicit public preferences, participants wanted to defer to others, such as health professionals or those with a lived experience of each condition, to make decisions about which conditions to include. Many participants saw benefit in including conditions with no available treatment. Participants agreed that gNBS should be fully publicly funded. CONCLUSION: How many and which conditions are included in a gNBS program will be a complex decision requiring detailed assessment of benefits and costs alongside public and professional engagement. Our study provides support for implementing gNBS for treatable childhood-onset conditions.

Gene selection for genomic newborn screening: Moving toward consensus?

PURPOSE: Gene selection for genomic newborn screening (gNBS) underpins the validity, acceptability, and ethical application of this technology. Existing gNBS gene lists are highly variable despite being based on shared principles of gene-disease validity, treatability, and age of onset. This study aimed to curate a gNBS gene list that builds upon existing efforts and provide a core consensus list of gene-disease pairs assessed by multiple expert groups worldwide. METHODS: Our multidisciplinary expert team curated a gene list using an open platform and multiple existing curated resources. We included severe treatable disorders with age of disease onset <5 years with established gene-disease associations and reliable variant detection. We compared the final list with published lists from 5 other gNBS projects to determine consensus genes and to identify areas of discrepancy. RESULTS: We reviewed 1279 genes and 604 met our inclusion criteria. Metabolic conditions comprised the largest group (25%), followed by immunodeficiencies (21%) and endocrine disorders (15%). We identified 55 consensus genes included by all 6 gNBS research projects. Common reasons for discrepancy included variable definitions of treatability and strength of gene-disease association. CONCLUSION: We have identified a consensus gene list for gNBS that can be used as a basis for systematic harmonization efforts internationally.

Performance of a cell-free DNA prenatal screening test, choice of prenatal procedure, and chromosome conditions identified during pregnancy after low-risk cell-free DNA screening.

OBJECTIVES: To evaluate the performance of cell-free DNA (cfDNA) screening for common fetal aneuploidies, choice of prenatal procedure, and chromosome conditions identified during pregnancy after low-risk cfDNA screening. METHOD: A single-center prenatal cfDNA screening test was employed to detect trisomies 21, 18, and 13 (T21, T18, T13) and sex chromosome aneuploidies (SCAs). Test performance, choice of prenatal procedure, and cytogenetic results in pregnancies with low-risk cfDNA screening were reviewed. RESULTS: CfDNA screening of 38,289 consecutive samples identified 720 (1.9%) pregnancies at increased risk for aneuploidy. Positive predictive values (PPVs) for high-risk singleton pregnancies were 98.5% (T21), 92.5% (T18) and 55.2% (T13). PPVs for SCAs ranged from 30.6% to 95.2%. Most women elected chorionic villus sampling for prenatal diagnosis of T21, T18 and T13; amniocentesis and/or postnatal testing were commonly chosen for SCAs. Cytogenetic tests from 616 screen-negative pregnancies identified 64 cases (12.7%) with chromosome conditions not detected by cfDNA screening, including triploidy (n = 30) and pathogenic and likely pathogenic copy number variants (n = 34). A further 15 (0.04%) false-negative common aneuploidy results were identified. CONCLUSIONS: CfDNA screening was highly accurate for detecting fetal aneuploidy in this general-risk obstetric population. Fetal ultrasound and prenatal diagnostic testing were important in identifying chromosome conditions in pregnancies screened as low-risk.

How should severity be understood in the context of reproductive genetic carrier screening?

Reproductive genetic carrier screening provides information about people's chance of having children with certain genetic conditions. Severity of genetic conditions is an important criterion for their inclusion in carrier screening programmes. However, the concept of severity is conceptually complex and underspecified. We analyse why severity is an important concept in carrier screening and for reproductive decision-making and show that assessments of severity can also have normative societal implications. While some genetic conditions are unambiguously associated with a high degree of suffering, there are many factors that contribute to how severe a condition is perceived to be, and perspectives will vary. Attempts to classify genetic conditions according to their severity tend to prioritise biomedical information at the expense of incorporating qualitative aspects of the impact of genetic conditions on people's lives. Further complexity arises because some genotypes can present with variable phenotypes and because some conditions are not always experienced in the same way by all people who have them. To acknowledge this complexity, we argue that an understanding of severity needs to distinguish between the severity of a genetic condition-requiring a generalised approach for purposes of policy development and programme design-and the severity of an instance of a genetic condition in a particular person. Families making reproductive decisions also require access to diverse experiences of the qualitative aspects of living with genetic conditions. As a result, reproductive carrier screening programmes must recognise and respond to the complexity inherent in determining the severity of genetic conditions.

"It becomes your whole life"-Exploring experiences of reciprocal translocation carriers and their partners.

Reciprocal translocation carriers are often diagnosed when they are experiencing difficulties conceiving or after a pregnancy affected by an unbalanced set of chromosomes inherited from the balanced carrier parent. Having a reciprocal translocation is not uncommon; carriers can benefit from reproductive options to achieve a healthy, chromosomally balanced, pregnancy. The aim of this study was to explore the lived experience of carriers and their partners. We conducted 13 semi-structured telephone interviews. Participants were recruited through Victorian Clinical Genetics Services and interviews took place between May and September 2020. Interview transcripts were analyzed using thematic analysis. Reciprocal translocation carriers and their partners described long term emotional and reproductive impacts, with carrier status identified at the time of prenatal diagnosis having marked emotional consequences. Couples facing reproductive challenges found the diagnosis created uncertainty for their future. When considering a pregnancy, couples worried about experiencing a miscarriage; during pregnancy, there was a reluctance to have an invasive diagnostic procedure due to fearing the risk of losing an unaffected pregnancy. Adaptation to their new reality involved having access to accurate information, peer support and maintaining hope. Couples valued having the option to know the carrier status of their children. The complex impacts of carrying a reciprocal translocation highlight the importance of access to specialist genetic counseling services to ensure couples are supported in understanding the implications of their translocation.

Experiences of receiving an increased chance of sex chromosome aneuploidy result from non-invasive prenatal testing in Australia: "A more complicated scenario than what I had ever realized".

Many non-invasive prenatal testing (NIPT) platforms screen for sex chromosome aneuploidy (SCA) and SCA analysis is generally included in Australia where NIPT is available as a self-funded test. Little is known about the experience of receiving an NIPT result indicating an increased chance of SCA. This study aimed to explore the experiences of people who received this result and their perspectives on the information, care, and support they received from healthcare practitioners (HCPs). Semi-structured interviews were conducted with people who received an NIPT result indicating an increased chance of SCA and continued their pregnancy. Most participants only had contact with a genetic counselor after receiving their result. Transcribed data were analyzed using rigorous thematic analysis to identify important patterns and themes. Participants (18 women, 2 male partners) described embarking on NIPT, primarily based on advice from their HCP and without much consideration. Consequently, participants expressed feeling unprepared for the unanticipated complexity of their NIPT result and were faced with making a time-sensitive decision about a condition they had not previously considered. While more pre-test information was desired, timely access to genetic counseling post-test assisted with adjustment to the result. These findings suggest that routinization of NIPT may be compromising informed decision-making, resulting in unpreparedness for an increased chance result. Given the increasing uptake and expanding scope of NIPT, resources should be dedicated to educating HCPs offering NIPT and ensuring timely access to genetic counseling post-result. With appropriate funding, genetics services may be able to play a central role in offering information and support to both people who undertake NIPT and their HCPs ordering the testing. Implementing a publicly funded screening program in Australia could assist with standardizing prenatal screening care pathways and consequently better access to appropriate resources.

Ethical considerations in gene selection for reproductive carrier screening.

Genetic carrier screening for reproductive purposes has existed for half a century. It was originally offered to particular ethnic groups with a higher prevalence of certain severe recessive or X-linked genetic conditions, or (as carrier testing) to those with a family history of a particular genetic condition. Commercial providers are increasingly offering carrier screening on a user-pays basis. Some countries are also trialing or offering public reproductive genetic carrier screening with whole populations, rather than only to those known to have a higher chance of having a child with an inherited genetic condition. Such programs broaden the ethical and practical challenges that arise in clinical carrier testing. In this paper we consider three aspects of selecting genes for population reproductive genetic carrier screening panels that give rise to important ethical considerations: severity, variable penetrance and expressivity, and scalability; we also draw on three exemplar genes to illustrate the ethical issues raised: CFTR, GALT and SERPINA1. We argue that such issues are important to attend to at the point of gene selection for RGCS. These factors warrant a cautious approach to screening panel design, one that takes into account the likely value of the information generated by screening and the feasibility of implementation in large and diverse populations. Given the highly complex and uncertain nature of some genetic variants, careful consideration needs to be given to the balance between delivering potentially burdensome or harmful information, and providing valuable information to inform reproductive decisions.

Standardized practices for RNA diagnostics using clinically accessible specimens reclassifies 75% of putative splicing variants.

PURPOSE: Genetic variants causing aberrant premessenger RNA splicing are increasingly being recognized as causal variants in genetic disorders. In this study, we devise standardized practices for polymerase chain reaction (PCR)-based RNA diagnostics using clinically accessible specimens (blood, fibroblasts, urothelia, biopsy). METHODS: A total of 74 families with diverse monogenic conditions (31% prenatal-congenital onset, 47% early childhood, and 22% teenage-adult onset) were triaged into PCR-based RNA testing, with comparative RNA sequencing for 19 cases. RESULTS: Informative RNA assay data were obtained for 96% of cases, enabling variant reclassification for 75% variants that can be used for genetic counseling (71%), to inform clinical care (32%) and prenatal counseling (41%). Variant-associated mis-splicing was highly reproducible for 28 cases with samples from ≥2 affected individuals or heterozygotes and 10 cases with ≥2 biospecimens. PCR amplicons encompassing another segregated heterozygous variant was vital for clinical interpretation of 22 of 79 variants to phase RNA splicing events and discern complete from partial mis-splicing. CONCLUSION: RNA diagnostics enabled provision of a genetic diagnosis for 64% of recruited cases. PCR-based RNA diagnostics has capacity to analyze 81.3% of clinically significant genes, with long amplicons providing an advantage over RNA sequencing to phase RNA splicing events. The Australasian Consortium for RNA Diagnostics (SpliceACORD) provide clinically-endorsed, standardized protocols and recommendations for interpreting RNA assay data.

Paternal retraction of a fragile X allele to normal size, showing normal function over two generations.

The FMR1 premutation (PM:55-199 CGG) is associated with fragile X-associated tremor/ataxia syndrome (FXTAS) and when maternally transmitted is at risk of expansion to a hypermethylated full mutation (FM: ≥ 200 CGG) that causes fragile X syndrome (FXS). We describe a maternally transmitted PM (77 CGG) that was passed to a son (103 CGG), and to a daughter (220-1822 CGG), who were affected with FXTAS and FXS, respectively. The male with the PM showed low-level mosaicism for normal size of 30 and 37 CGG. This male had two offspring: one female mosaic for PM and FM (56, 157, >200 CGG) and another with only a 37 CGG allele detected in multiple tissues, neither with a clinical phenotype. The female with the 37 CGG allele showed normal levels of FMR1 methylation and mRNA and passed this 37 CGG allele to one of her daughters, who was also unaffected. These findings show that post-zygotic paternal retraction can lead to low-level mosaicism for normal size alleles, with these normal alleles being functional when passed over two generations.

Health practitioners' perceptions of the barriers and enablers to the implementation of reproductive genetic carrier screening: A systematic review.

BACKGROUND: As interest in reproductive genetic carrier screening rises, with increased availability, the role of healthcare practitioners is central in guiding uptake aligned with a couples' values and beliefs. Therefore, practitioners' views on implementation are critical to the success of any reproductive genetic carrier screening programme. AIM: To explore healthcare practitioners' perceptions of the barriers and enablers to implementation. MATERIALS & METHODS: We undertook a systematic review of the literature searching seven databases using health practitioner, screening and implementation terms returning 490 articles. RESULTS: Screening led to the inclusion of 26 articles for full-text review. We found three interconnected themes relating to reproductive genetic carrier screening: (i) use and impact, (ii) practitioners' beliefs and expectations and (iii) resources. DISCUSSION: Barriers and enablers to implementation were present within each theme and grouping these determinants by (a) community for example lack of public interest, (b) practitioner for example lack of practitioner time and (c) organisation for example lack of effective metrics, reveals a preponderance of practitioner barriers and organisational enablers. Linking barriers with potential enablers leaves several barriers unresolved (e.g., costs for couples) implying additional interventions may be required. CONCLUSION: Future research should draw on the findings from this study to develop and test strategies to facilitate appropriate offering of reproductive genetic carrier screening by healthcare practitioners.

Factors influencing medical practitioner participation in population carrier screening for cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) carrier screening should be offered to people planning a pregnancy or in early pregnancy, according to current recommendations. However, research indicates rates of offering CF carrier screening are low. Health professionals (HPs) play an important role in offering population carrier screening. AIMS: To determine the opinions, knowledge and practice patterns of HPs with regard to the routine offering of population carrier screening for CF. MATERIALS AND METHODS: Five key informant interviews informed the development of an online questionnaire which was distributed to a select group of HPs involved in prenatal care in Victoria, Australia. RESULTS: Of the participants who completed the questionnaire (n = 87), 35.6% reported offering CF carrier screening to all patients attending for preconception or early pregnancy consultations. High referrers of CF carrier screening were more likely to be female, work in the private sector, in metropolitan areas and specialise as an obstetrician. High referrers demonstrated a greater level of knowledge of CF and carrier screening than low referrers (t = -3.779, P < 0.001). Low referrers perceived more barriers to offering carrier screening than high referrers (t = 2.125, P = 0.037). Low referrers were more likely to perceive lack of community awareness and HP knowledge as a barrier to offering CF carrier screening, compared to high referrers, who were more likely to perceive time constraints as a barrier. CONCLUSIONS: To promote routine offering of population CF carrier screening, resources are needed to improve knowledge and provide clinical support thereby reducing perceived barriers.

Genome-wide noninvasive prenatal screening for carriers of balanced reciprocal translocations.

PURPOSE: Balanced reciprocal translocation carriers are at increased risk of producing gametes with unbalanced forms of the translocation leading to miscarriage, fetal anomalies, and birth defects. We sought to determine if genome-wide cell-free DNA based noninvasive prenatal screening (gw-NIPS) could provide an alternative to prenatal diagnosis for carriers of these chromosomal rearrangements. METHODS: This pilot series comprises a retrospective analysis of gw-NIPS and clinical outcome data from 42 singleton pregnancies where one parent carried a balanced reciprocal translocation. Gw-NIPS was performed between August 2015 and March 2018. Inclusion criteria required at least one translocation segment to be ≥15 Mb in size. RESULTS: Forty samples (95%) returned an informative result; 7 pregnancies (17.5%) were high risk for an unbalanced translocation and confirmed after diagnostic testing. The remaining 33 informative samples were low risk and confirmed after diagnostic testing or normal newborn physical exam. Test sensitivity of 100% (95% confidence interval [CI]: 64.6-100%) and specificity of 100% (95% CI: 89.6-100%) were observed for this pilot series. CONCLUSION: We demonstrate that gw-NIPS is a potential option for a majority of reciprocal translocation carriers. Further confirmation of this methodology could lead to adoption of this noninvasive alternative.

International perspectives on the implementation of reproductive carrier screening.

Reproductive carrier screening started in some countries in the 1970s for hemoglobinopathies and Tay-Sachs disease. Cystic fibrosis carrier screening became possible in the late 1980s and with technical advances, screening of an ever increasing number of genes has become possible. The goal of carrier screening is to inform people about their risk of having children with autosomal recessive and X-linked recessive disorders, to allow for informed decision making about reproductive options. The consequence may be a decrease in the birth prevalence of these conditions, which has occurred in several countries for some conditions. Different programs target different groups (high school, premarital, couples before conception, couples attending fertility clinics, and pregnant women) as does the governance structure (public health initiative and user pays). Ancestry-based offers of screening are being replaced by expanded carrier screening panels with multiple genes that is independent of ancestry. This review describes screening in Australia, Cyprus, Israel, Italy, Malaysia, the Netherlands, Saudi Arabia, the United Kingdom, and the United States. It provides an insight into the enormous variability in how reproductive carrier screening is offered across the globe. This largely relates to geographical variation in carrier frequencies of genetic conditions and local health care, financial, cultural, and religious factors.

FMR1 allele size distribution in 35,000 males and females: a comparison of developmental delay and general population cohorts.

PURPOSE: Developmental delay phenotypes have been associated with FMR1 premutation (PM: 55-200 CGG repeats) and "gray zone" (GZ: 45-54 CGG repeats) alleles. However, these associations have not been confirmed by larger studies to be useful in pediatric diagnostic or screening settings. METHODS: This study determined the prevalence of PM and GZ alleles in two independent cohorts of 19,076 pediatric referrals to developmental delay diagnostic testing through Victorian Clinical Genetics Service (cohort 1: N = 10,235; cohort 2: N = 8841), compared with two independent general population cohorts (newborn screening N = 1997; carrier screening by the Victorian Clinical Genetics Service prepair program N = 14,249). RESULTS: PM and GZ prevalence rates were not significantly increased (p > 0.05) in either developmental delay cohort (male PM: 0.12-0.22%; female PM: 0.26-0.33%; male GZ: 0.68-0.69%; female GZ: 1.59-2.13-%) compared with general population cohorts (male PM: 0.20%; female PM: 0.27-0.82%; male GZ: 0.79%; female GZ: 1.43-2.51%). Furthermore, CGG size distributions were comparable across datasets, with each having a modal value of 29 or 30 and ~1/3 females and ~1/5 males having at least one allele with ≤26 CGG repeats. CONCLUSION: These data do not support the causative link between PM and GZ expansions and developmental-delay phenotypes in pediatric settings.

Correction: Reproductive genetic carrier screening for cystic fibrosis, fragile X syndrome, and spinal muscular atrophy in Australia: outcomes of 12,000 tests.

Zoe McDonald, BSc, was omitted from the list of article coauthors. Her name should have been included as the seventh author, following Clare Elizabeth Hunt. Her affiliation is Victorian Clinical Genetics Services, Parkville, Victoria, Australia. The authors regret the error.

Reproductive genetic carrier screening for cystic fibrosis, fragile X syndrome, and spinal muscular atrophy in Australia: outcomes of 12,000 tests.

PurposeTo describe our experience of offering simultaneous genetic carrier screening for cystic fibrosis (CF), fragile X syndrome (FXS), and spinal muscular atrophy (SMA).MethodsCarrier screening is offered through general practice, obstetrics, fertility, and genetics settings before or in early pregnancy. Carriers are offered genetic counseling with prenatal/preimplantation genetic diagnosis available to those at increased risk.ResultsScreening of 12,000 individuals revealed 610 carriers (5.08%; 1 in 20): 342 CF, 35 FXS, 241 SMA (8 carriers of 2 conditions), approximately 88% of whom had no family history. At least 94% of CF and SMA carriers' partners were tested. Fifty couples (0.42%; 1 in 240) were at increased risk of having a child with one of the conditions (14 CF, 35 FXS, and 1 SMA) with 32 pregnant at the time of testing. Of these, 26 opted for prenatal diagnosis revealing 7 pregnancies affected (4 CF, 2 FXS, 1 SMA).ConclusionThe combined affected pregnancy rate is comparable to the population risk for Down syndrome, emphasizing the need to routinely offer carrier screening. The availability of appropriate genetic counseling support and a collaborative approach between laboratory teams, genetics services, health professionals offering screening, and support organizations is essential.

Informed decision making and psychosocial outcomes in pregnant and nonpregnant women offered population fragile X carrier screening.

PurposePopulation-based carrier screening for fragile X syndrome (FXS) is still not universally endorsed by professional organizations due to concerns around genetic counseling for complex information and potential for psychosocial harms.MethodsWe determined uptake levels, decision making, and psychosocial impact in a prospective study of pregnant and nonpregnant Australian women offered FXS carrier screening in clinical settings. Women received pretest genetic counseling, and completed questionnaires when deciding and one month later.ResultsOf 1,156 women recruited, 83.1% returned the first questionnaire with 70.6% nonpregnant and 58.8% pregnant women choosing testing (χ2=16.98, P<0.001). Overall, informed choice was high in both nonpregnant (77.4%) and pregnant (72.9%) women (χ2=0.21, P=0.644), and more tested (76.0%) than not-tested (66.7%) women (χ2=6.35, P=0.012) made an informed choice. Measures of depression, stress, and anxiety were similar to population norms for ~85% of women. Decisional conflict and regret were generally low; however, decisional uncertainty and regret were greater in pregnant than nonpregnant women, and not-tested than tested women (uncertainty: χ2=18.51, P<0.001 and χ2=43.11, P<0.001, respectively; regret: χ2=6.61, P<0.037 and χ2=35.54, P<0.001, respectively).ConclusionWe provide evidence to inform guidelines that population FXS carrier screening can be implemented with minimal psychosocial harms following appropriate information and prescreening genetic counseling.

"It wasn't a disaster or anything": Parents' experiences of their child's uncertain chromosomal microarray result.

Chromosomal microarray is an increasingly utilized diagnostic test, particularly in the pediatric setting. However, the clinical significance of copy number variants detected by this technology is not always understood, creating uncertainties in interpreting and communicating results. The aim of this study was to explore parents' experiences of an uncertain microarray result for their child. This research utilized a qualitative approach with a phenomenological methodology. Semi-structured interviews were conducted with nine parents of eight children who received an uncertain microarray result for their child, either a 16p11.2 microdeletion or 15q13.3 microdeletion. Interviews were transcribed verbatim and thematic analysis was used to identify themes within the data. Participants were unprepared for the abnormal test result. They had a complex perception of the extent of their child's condition and a mixed understanding of the clinical relevance of the result, but were accepting of the limitations of medical knowledge, and appeared to have adapted to the result. The test result was empowering for parents in terms of access to medical and educational services; however, they articulated significant unmet support needs. Participants expressed hope for the future, in particular that more information would become available over time. This research has demonstrated that parents of children who have an uncertain microarray result appeared to adapt to uncertainty and limited availability of information and valued honesty and empathic ongoing support from health professionals. Genetic health professionals are well positioned to provide such support and aid patients' and families' adaptation to their situation as well as promote empowerment. © 2016 Wiley Periodicals, Inc.