[Carrier screening for 223 monogenic diseases in Chinese population: a multi-center study in 33 104 individuals].

OBJECTIVE: To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale, multicenter carrier screening. METHODS: This study was conducted among a total of 33 104 participants (16 610 females) from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods. RESULTS: The overall combined carrier frequency was 55.58% for 197 autosomal genes and 1.84% for 26 X-linked genes in these participants.Among the 16 669 families, 874 at-risk couples (5.24%) were identified.Specifically, 584 couples (3.50%) were at risk for autosomal genes, 306(1.84%) for X-linked genes, and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A, 393 couples), HBA1/HBA2(α-thalassemia, 36 couples), PAH (phenylketonuria, 14 couples), and SMN1(spinal muscular atrophy, 14 couples).The most frequently detected X-linked at-risk genes were G6PD (G6PD deficiency, 236 couples), DMD (Duchenne muscular dystrophy, 23 couples), and FMR1(fragile X syndrome, 17 couples).After excluding GJB2 c.109G>A, the detection rate of at-risk couples was 3.91%(651/16 669), which was lowered to 1.72%(287/16 669) after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95% of at-risk couples, while screening for the top 54 genes further increased the detection rate to over 99%. CONCLUSION: This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing, genetic counseling for specific genes or gene variants can be challenging, and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

Antenatal reproductive screening for pregnant people including preconception: Provides the best reproductive opportunity for informed consent, quality, and safety.

INTRODUCTION: This antenatal screening review will include reproductive screening evidence and approaches for pre-conception and post-conception, using first to third trimester screening opportunities. METHODS: Focused antenatal screening peer-reviewed publications were evaluated and summarized. RESULTS: Evidenced-based reproductive antenatal screening elements should be offered and discussed, with the pregnancy planning or pregnant person, during Preconception (genetic carrier screening for reproductive partners, personal and family (including reproductive partner) history review for increased genetic and pregnancy morbidity risks); First Trimester (fetal dating with ultrasound; fetal aneuploidy screening plus consideration for expanded fetal morbidity criteria, if appropriate; pregnant person preeclampsia screening; early fetal anatomy screening; early fetal cardiac screening); Second Trimester for standard fetal anatomy screening (18-22 weeks) including cardiac; pregnant person placental and cord pathology screening; pregnant person preterm birth screening with cervical length measurement); Third Trimester (fetal growth surveillance; continued preterm birth risk surveillance). CONCLUSION: Antenatal reproductive screening has multiple elements, is complex, is time-consuming, and requires the use of pre- and post-testing counselling for most screening elements. The use of preconception and trimesters 'one to three' requires clear patient understanding and buy-in. Informed consent and knowledge transfer is a main goal for antenatal reproductive screening approaches.

Identifying hemophilia B carriers: Utility of aPTT, factor IX levels and ratios of factor IX to other Vitamin K dependent factors.

INTRODUCTION: Diagnosing hemophilia B (HB) carrier status is important to manage bleeding in carriers and to prevent bleeding in potential offspring. Without a family history of hemophilia, diagnosing HB carrier status is challenging. Genetic testing is the gold-standard, however it is reserved for individuals with a high suspicion of carrier status. AIMS: To describe the distribution of activated partial thromboplastin time (aPTT) and factor IX coagulant (FIX:C) levels in HB carriers and assess the ratio of FIX:C to other Vitamin K dependent factors (FII:C, FVII:C, FX:C) as an indicator of HB carrier status. METHODS: In this retrospective, single-centre cohort study, subjects were included if they were obligate or genetically proven HB carriers. Distributions of aPTT and FIX:C were described and the relationship between FIX:C levels in carriers and severity of familial HB was analysed. Ratios of FIX:C to FII:C, FVII:C, FX:C were calculated. RESULTS: Seventy-two female HB carriers (median age: 34 years; IQR 24-43) were included. Median aPTT and FIX:C levels were 33.0 s [IQR 30.0-37.0] and 57 IU/dL [IQR 43-74]. Fifteen carriers (21%) had mild HB (FIX:C levels of 10-40 IU/dL). FIX:C levels trended higher in carriers of mild HB versus carriers of moderate/severe HB. In six carriers, the median ratio of FIX:C to other Vitamin K dependent factors was 0.44, with 92% of ratios being ≤ 0.75. CONCLUSION: aPTT and FIX:C levels were unreliable in diagnosing HB carrier status. A low ratio of FIX:C to other Vitamin K dependent factors may be a useful marker of HB carrier status.

Genetic Screening-Emerging Issues.

In many countries, some form of genetic screening is offered to all or part of the population, either in the form of well-organized screening programs or in a less formalized way. Screening can be offered at different phases of life, such as preconception, prenatal, neonatal and later in life. Screening should only be offered if the advantages outweigh the disadvantages. Technical innovations in testing and treatment are driving changes in the field of prenatal and neonatal screening, where many jurisdictions have organized population-based screening programs. As a result, a greater number and wider range of conditions are being added to the programs, which can benefit couples' reproductive autonomy (preconception and prenatal screening) and improve early diagnosis to prevent irreversible health damage in children (neonatal screening) and in adults (cancer and cascade screening). While many developments in screening are technology-driven, citizens may also express a demand for innovation in screening, as was the case with non-invasive prenatal testing. Relatively new emerging issues for genetic screening, especially if testing is performed using DNA sequencing, relate to organization, data storage and interpretation, benefit-harm ratio and distributive justice, information provision and follow-up, all connected to acceptability in current healthcare systems.

Comprehensive genomic filtering algorithm to expose the cause of skewed X chromosome inactivation. The proof of concept in female haemophilia expression.

BACKGROUND: Exploring the expression of X linked disorders like haemophilia A (HA) in females involves understanding the balance achieved through X chromosome inactivation (XCI). Skewed XCI (SXCI) may be involved in symptomatic HA carriers. We aimed to develop an approach for dissecting the specific cause of SXCI and verify its value in HA. METHODS: A family involving three females (two symptomatic with severe/moderate HA: I.2, the mother, and II.1, the daughter; one asymptomatic: II.2) and two related affected males (I.1, the father and I.3, the maternal uncle) was studied. The genetic analysis included F8 mutational screening, multiplex ligation-dependent probe amplification, SNP microarray, whole exome sequencing (WES) and Sanger sequencing. XCI patterns were assessed in ectoderm/endoderm and mesoderm-derived tissues using AR-based and RP2-based systems. RESULTS: The comprehensive family analysis identifies I.2 female patient as a heterozygous carrier of F8:p.(Ser1414Ter) excluding copy number variations. A consistent XCI pattern of 99.5% across various tissues was observed. A comprehensive filtering algorithm for WES data was designed, developed and applied to I.2. A Gly58Arg missense variant in VMA21 was revealed as the cause for SXCI.Each step of the variant filtering system takes advantage of publicly available genomic databases, non-SXCI controls and case-specific molecular data, and aligns with established concepts in the theoretical background of SXCI. CONCLUSION: This study acts as a proof of concept for our genomic filtering algorithm's clinical utility in analysing X linked disorders. Our findings clarify the molecular aspects of SXCI and improve genetic diagnostics and counselling for families with X linked diseases like HA.

Expanded targeted preconception screening panel in Israel: findings and insights.

BACKGROUND: We aimed to analyse the efficacy and added value of a targeted Israeli expanded carrier screening panel (IL-ECSP), beyond the first-tier test covered by the Israeli Ministry of Health (IMOH) and the second-tier covered by the Health Maintenance Organisations (HMOs). METHODS: A curated variant-based IL-ECSP, tailored to the uniquely diverse Israeli population, was offered at two tertiary hospitals and a major genetics laboratory. The panel includes 1487 variants in 357 autosomal recessive and X-linked genes. RESULTS: We analysed 10 115 Israeli samples during an 18-month period. Of these, 6036 (59.7%) were tested as couples and 4079 (40.3%) were singles. Carriers were most frequently identified with mutations in the following genes: GJB2/GJB6 (1:22 allele frequency), CFTR (1:28), GBA (1:34), TYR (1:39), PAH (1:50), SMN1 (1:52) and HEXA (1:56). Of 3018 couples tested, 753 (25%) had no findings, in 1464 (48.5%) only one partner was a carrier, and in 733 (24.3%) both were carriers of different diseases. We identified 79 (2.6%) at-risk couples, where both partners are carriers of the same autosomal recessive condition, or the female carries an X-linked disease. Importantly, 48.1% of these would not have been detected by ethnically-based screening tests currently provided by the IMOH and HMOs, for example, variants in GBA, TYR, PAH and GJB2/GJB6. CONCLUSION: This is the largest cohort of targeted ECSP testing, tailored to the diverse Israeli population. The IL-ECSP expands the identification of couples at risk and empowers their reproductive choices. We recommend endorsing an expanded targeted panel to the National Genetic Carrier Screening programme.

The Early Care (0-3 Years) In Duchenne Muscular Dystrophy Meeting Report.

Objective: This report summarizes the key discussions from the "Early Care (0-3 years) in Duchenne Muscular Dystrophy" meeting, which aimed to address the challenges and opportunities in the diagnosis and care of Duchenne muscular dystrophy (DMD) and female carriers within the 0-3-year age group. Methods: The meeting brought together experts and healthcare providers who shared insights, discussed advancements in DMD care, and identified research needs. Presentations covered diagnostic challenges, approved therapies, clinical trials, identification of young female carriers, and the importance of clinical care and support for families. Results: The meeting highlighted the importance of timely diagnosis and the lack of evidence-based guidelines for the care of children with DMD aged 0-3 years. Diagnostic challenges were discussed, including delays in receiving a DMD diagnosis and disparities based on ethnicity. The potential benefits and process of newborn screening were addressed.Approved therapeutic interventions, such as corticosteroids and exon-skipping drugs, were explored, with studies indicating the potential benefits of early initiation of corticosteroid therapy and the safety of exon-skipping drugs in DMD. Clinical trials involving infants and young boys were discussed, focusing on drugs like ataluren, vamorolone, and gene therapies.The meeting emphasized the importance of clinical care and support for families, including comprehensive information provision, early intervention services, and individualized support. The identification and care of young female carriers were also addressed. Conclusion: The meeting provided a platform for experts and healthcare providers to discuss and identify key aspects of early care for children with DMD aged 0-3 years. The meeting emphasized the need for early diagnosis, evidence-based guidelines, and comprehensive care and support for affected children and their families. Further research, collaboration, and the development of consensus guidelines are needed to improve early diagnosis, treatment, and outcomes in this population.

Exploring attitudes and experiences with reproductive genetic carrier screening among couples seeking medically assisted reproduction: a longitudinal survey study.

PURPOSE: This study aimed to assess the attitudes and experiences of subfertile couples applying for medically assisted reproduction (MAR) using their own gametes towards reproductive genetic carrier screening (RGCS) for monogenic conditions. METHODS: A prospective survey study was conducted where subfertile couples were recruited from the fertility centre of a university hospital in Flanders, Belgium. Participants were offered RGCS free of charge and completed self-administered questionnaires at three different time points. RESULTS: The study sample consisted of 26 couples. Most participants had no children, did not consider themselves as religious, and had some form of higher education. Overall, attitudes towards RGCS were mostly positive and the intention to participate in RGCS was high. Anxiety scores were only elevated and clinically relevant for a limited number of participants. A large proportion of participants would consider preventive reproductive options like prenatal diagnosis or in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) combined with pre-implantation genetic testing for monogenic conditions (PGT-M) in the event of an increased likelihood of conceiving a child with a hereditary condition. Participants were satisfied with their decision to undergo RGCS, and the majority would recommend RGCS to other couples. CONCLUSION: Our study findings suggest that subfertile couples applying for MAR using their own gametes find RGCS acceptable and have a positive attitude towards it. This study provides valuable insights into the perspectives of these couples, highlighting the need for appropriate counseling and timely information provision.

Molecular diagnosis, clinical evaluation and phenotypic spectrum of Townes-Brocks syndrome: insights from a large Chinese hearing loss cohort.

BACKGROUND: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterised by multiple malformations. Due to its phenotypic heterogeneity and rarity, diagnosis and recognition of TBS can be challenging and there has been a lack of investigation of patients with atypical TBS in large cohorts and delineation of their phenotypic characteristics. METHODS: We screened SALL1 and DACT1 variants using next-generation sequencing in the China Deafness Genetics Consortium (CDGC) cohort enrolling 20 666 unrelated hearing loss (HL) cases. Comprehensive clinical evaluations were conducted on seven members from a three-generation TBS family. Combining data from previously reported cases, we also provided a landscape of phenotypes and genotypes of patients with TBS. RESULTS: We identified five novel and two reported pathogenic/likely pathogenic (P/LP) SALL1 variants from seven families. Audiological features in patients differed in severity and binaural asymmetry. Moreover, previously undocumented malformations in the middle and inner ear were detected in one patient. By comprehensive clinical evaluations, we further provide evidence for the causal relationship between SALL1 variation and certain endocrine abnormalities. Penetrance analysis within familial contexts revealed incomplete penetrance among first-generation patients with TBS and a higher disease burden among their affected offspring. CONCLUSION: This study presents the first insight of genetic screening for patients with TBS in a large HL cohort. We broadened the phenotypic-genotypic spectrum of TBS and our results supported an underestimated prevalence of TBS. Due to the rarity and phenotypic heterogeneity of rare diseases, broader spectrum molecular tests, especially whole genome sequencing, can improve the situation of underdiagnosis and provide effective recommendations for clinical management.

Parental request for familial carrier testing in early childhood: The genetic counseling perspective.

Professional guidelines generally caution against carrier testing in minors, though prior research indicates parents request and providers sometimes facilitate testing for unaffected siblings of a child affected by a genetic disorder. We investigated the perspectives of genetic counselors in North America regarding carrier testing prior to adolescence. Practicing genetic counselors (n = 177) responded to an electronic survey assessing their willingness to facilitate testing in four hypothetical scenarios and their evaluation of parental motivations. Participants did not find parental arguments for testing persuasive, and most were unwilling to facilitate carrier testing in children. A significant interaction effect indicated the presence of nonactionable carrier-associated health risks in adulthood made participants significantly less hesitant when the mode of inheritance was X-linked. Participants considered parental motivations that center the child's interests as significantly more persuasive. This study suggests genetic counselors are resistant to carrier testing for familial disorders in young children and tend to align with current guidelines, yet they recognize nuance in various cases. Further investigation into this topic is warranted to support genetic counselors facing these requests as the ethics of pediatric carrier testing continues to be debated.

Educational tools support informed decision-making for genetic carrier screening in a heterogenic Israeli population.

Reproductive genetic carrier screening (RGCS) aims to provide couples with information to make informed decisions. Since 2013, the Israeli Carrier Screening Program has been offered routinely and free of charge to all Israelis of reproductive age, personalized based on religion, ethnicity, and village/tribe where a disorder is frequent. This study evaluated the impact of two educational tools on an informed choice on RGCS uptake and satisfaction with counselling within a heterogeneous population in northern Israel. Participants from diverse sociodemographic population groups were randomly assigned to watch an animated film, read a booklet conveying the same information, or receive no information before counselling for RGCS, and asked to complete pre- and post-counselling questionnaires. A higher informed-decision rate was demonstrated in the film (n=93/141, 66%) and booklet (n=88/131, 67%) groups vs. the non-intervention group (n=62/143, 43%) (P<0.001), assessed by the Multidimensional Measure of Informed Choice. Multivariate logistic regression analysis revealed that allocation to an intervention group, Jewish ethnicity and higher education level, best predicted informed choice. Most participants expressed high levels of satisfaction with the counselling process, regardless of group assignment. While only a minority of participants reported seeking information prior to visiting the clinic, the pre-counselling information interventions were well accepted. Pre-counselling self-learning educational tools should be promoted, easily available, and adjusted linguistically and culturally to targeted populations, to avoid unwanted "automatic" compliance of tested individuals and maximize the potential of informed decision-making. Our study can be applied to other countries where majority and minority ethnic groups access genetic services.

Using a theory informed approach to design, execute, and evaluate implementation strategies to support offering reproductive genetic carrier screening in Australia.

BACKGROUND: Health care professionals play a central role in offering reproductive genetic carrier screening but face challenges when integrating the offer into practice. The aim of this study was to design, execute, and evaluate theory-informed implementation strategies to support health care professionals in offering carrier screening. METHODS: An exploratory multi-method approach was systematically employed based on the Theoretical Domain Framework (TDF). Implementation strategies were designed by aligning TDF barriers reported by health care professionals involved in a large carrier screening study, to behaviour change techniques combined with study genetic counsellors' experiential knowledge. The strategies were trialled with a subset of health care professionals and evaluated against controls, using findings from questionnaires and interviews with healthcare professionals. The primary outcome measure was the number of couples who initiated enrolment. RESULTS: Health care professionals (n = 151) reported barriers in the TDF Domains of skills, e.g., lack of practice in offering screening, and challenges of environmental context and resources, e.g., lack of time, which informed the design of a skills video and a waiting room poster using the TDF-behaviour change technique linking tool. Following implementation, (Skills video n = 29 vs control n = 31 and Poster n = 46 vs control n = 34) TDF barrier scores decreased across all groups and little change was observed in the primary outcome measure. The skills video, though welcomed by health care professionals, was reportedly too long at seven minutes. The waiting room poster was seen as easily implementable. CONCLUSIONS: As carrier screening moves towards mainstream healthcare, health care professionals report barriers to offering screening. To meet their needs, developing and testing experiential and theory-informed strategies that acknowledge contextual factors are essential.

Carriers of autosomal recessive conditions: are they really 'unaffected?'

Mendel's Law of Dominance suggests that recessive disease expression requires the inheritance of two mutated alleles as the dominant, wildtype allele suppresses disease presentation leading to the expression of physiological normal phenotypes. However, there is existing evidence that challenges this school of thought. Here, we summarise existing literature evaluating metabolic and health impacts among carriers of autosomal recessive conditions, focusing on phenylketonuria (PKU), classical homocystinuria, galactosemia and Usher syndrome as examples. Our findings suggest that carriers, often described as 'unaffected', may actually display attenuated symptoms for the recessive disease they are carrying. For instance, PKU is an inborn error of metabolism characterised by the build-up of plasma phenylalanine attributed to the deficiency of the phenylalanine hydroxylase (PAH) enzyme. While less severe, PKU carriers also exhibit this impaired enzymatic activity, leading to elevated plasma phenylalanine levels, especially after phenylalanine consumption. Related to these metabolic alterations in the PAH pathway, there is early evidence to suggest that PKU carriers may have compromised cognitive and mental health outcomes. Overall, research on the health and metabolic impacts of PKU carriers is sparse, with most studies conducted several decades ago. However, early evidence suggests that intermediate phenotypes among carriers of autosomal recessive conditions are plausible. The illustrated possible intermediate phenotypes observed among carriers necessitates future research to determine possible clinical implications among this population.

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.

Recurrent, founder and hypomorphic variants contribute to the genetic landscape of Joubert syndrome.

BACKGROUND: Joubert syndrome (JS) is a neurodevelopmental ciliopathy characterised by a distinctive mid-hindbrain malformation, the 'molar tooth sign'. Over 40 JS-associated genes are known, accounting for two-thirds of cases. METHODS: While most variants are novel or extremely rare, we report on 11 recurring variants in seven genes, including three known 'founder variants' in the Ashkenazi Jewish, Hutterite and Finnish populations. We evaluated variant frequencies in ~550 European patients with JS and compared them with controls (>15 000 Italian plus gnomAD), and with an independent cohort of ~600 JS probands from the USA. RESULTS: All variants were markedly enriched in the European JS cohort compared with controls. When comparing allele frequencies in the two JS cohorts, the Ashkenazim founder variant (TMEM216 c.218G>T) was significantly enriched in American compared with European patients with JS, while MKS1 c.1476T>G was about 10 times more frequent among European JS. Frequencies of other variants were comparable in the two cohorts. Genotyping of several markers identified four novel European founder haplotypes.Two recurrent variants (MKS1 c.1476T>G and KIAA0586 c.428delG), have been detected in homozygosity in unaffected individuals, suggesting they could act as hypomorphic variants. However, while fibroblasts from a MKS1 c.1476T>G healthy homozygote showed impaired ability to form primary cilia and mildly reduced ciliary length, ciliary parameters were normal in cells from a KIAA0586 c.428delG healthy homozygote. CONCLUSION: This study contributes to understand the complex genetic landscape of JS, explain its variable prevalence in distinct geographical areas and characterise two recurrent hypomorphic variants.

Experience using singleton exome sequencing of probands as an approach to preconception carrier screening in consanguineous couples.

BACKGROUND: Consanguineous couples have an increased risk of severe diseases in offspring due to autosomal recessive disorders. Exome sequencing (ES) offers the possibility of extensive preconception carrier screening (PCS) in consanguineous couples who may be at risk of rare genetic disorders. METHODS: We retrospectively analysed ES data from 65 probands affected with rare genetic disorders born from consanguineous couples. We explored diagnostic yield and carrier status for recessive disorders. RESULTS: The overall diagnostic yield in a singleton approach was 53.8%, mostly recessive variants. In a hypothetical exome-based PCS, only 11.7% of these causative rare variants would have been missed in the filtering process. Carrier screening for recessive conditions allowed the identification of at least one additional pathogenic or likely pathogenic variant in 85.7% of the probands, being the majority with a gene carrier frequency <1 in 200. In addition, considering only clinically actionable conditions, we estimated that 12.3% of our close consanguineous couples may be at risk for an additional recessive disease. CONCLUSIONS: Our results demonstrate that ES outperforms panel-based screening in a PCS context in consanguineous couples and could potentially increase their reproductive autonomy and facilitate informed decision-making.

Simplified and more sensitive criteria for identifying individuals with pathogenic CDH1 variants.

BACKGROUND: Hereditary diffuse gastric cancer (HDGC) is an autosomal-dominant syndrome most often caused by pathogenic variants in CDH1. The International Gastric Cancer Linkage Consortium (IGCLC) recently updated its criteria for genetic testing. The purpose of this study was to estimate the sensitivity of IGCLC's 2020 criteria for identifying carriers of CDH1 pathogenic variants and to formulate a new set of criteria that is simpler and more sensitive. METHODS: Medical histories of 112 CDH1 mutation carriers, identified predominantly by multigene panel testing, and their 649 family members were reviewed. The percentage of subjects fulfilling the IGCLC 2015 and 2020 criteria was calculated, once without making any assumptions about unavailable pathology, and once assuming gastric cancer to be diffuse when pathology was unavailable. For comparison, we calculated the percentage of subjects who fulfilled our proposed criteria. RESULTS: When making no assumptions about missing pathology, a small (19%) and equal percentage of CDH1 mutation carriers fulfilled the IGCLC 2015 and 2020 criteria. When assuming unspecified gastric cancer to be diffuse, 45 out of 112 (40%) subjects met the 2015 criteria and 53 out of 112 (47%) met the 2020 criteria. Eighty-seven per cent (97/112) fulfilled our proposed criteria. CONCLUSION: In consecutive cases, mostly unselected for clinical criteria of HDGC, the IGCLC 2020 criteria are, at best, marginally more sensitive than previous iterations, but they are also more cumbersome. Unavailable cancer pathology reports are a real-world obstacle to their proper application. Our proposed Yale criteria both address this issue and offer significantly greater sensitivity than the IGCLC 2020 criteria.

UK consensus recommendations for clinical management of cancer risk for women with germline pathogenic variants in cancer predisposition genes: RAD51C, RAD51D, BRIP1 and PALB2.

Germline pathogenic variants (GPVs) in the cancer predisposition genes BRCA1, BRCA2, MLH1, MSH2, MSH6, BRIP1, PALB2, RAD51D and RAD51C are identified in approximately 15% of patients with ovarian cancer (OC). While there are clear guidelines around clinical management of cancer risk in patients with GPV in BRCA1, BRCA2, MLH1, MSH2 and MSH6, there are few guidelines on how to manage the more moderate OC risk in patients with GPV in BRIP1, PALB2, RAD51D and RAD51C, with clinical questions about appropriateness and timing of risk-reducing gynaecological surgery. Furthermore, while recognition of RAD51C and RAD51D as OC predisposition genes has been established for several years, an association with breast cancer (BC) has only more recently been described and clinical management of this risk has been unclear. With expansion of genetic testing of these genes to all patients with non-mucinous OC, new data on BC risk and improved estimates of OC risk, the UK Cancer Genetics Group and CanGene-CanVar project convened a 2-day meeting to reach a national consensus on clinical management of BRIP1, PALB2, RAD51D and RAD51C carriers in clinical practice. In this paper, we present a summary of the processes used to reach and agree on a consensus, as well as the key recommendations from the meeting.