Cystic Fibrosis Carrier Research Articles

An evaluation of the first ten years of Newborn Screening for cystic fibrosis in Ireland

Abstract Ireland has the world’s highest incidence of cystic fibrosis (CF). Newborn screening for CF (NBSCF) improves outcomes but identifies carriers and may yield false positive/inconclusive results. This study aimed to evaluate the performance of the first 10 years of the Irish NBSCF programme. Data collected by the programme between 01st July 2011 and 30th June 2021 were analysed, including cases of CF, CF carriers and Cystic Fibrosis Screen Positive Inconclusive Diagnosis (CFSPID). Microsoft Excel was used to calculate sensitivity, specificity and positive predictive value (PPV). Results were compared to European Cystic Fibrosis Society (ECFS) standards. Overall 650,809 neonates were screened, with 290 cases of CF, 533 CF carriers and 21 CFSPIDs reported. NBSCF identified 284 (98%) of the children with CF, sensitivity was 97.93% (95% CI 96.29-99.57), specificity was 99.91% (95% CI 99.91-99.92%), PPV was 0.34 (95% CI 0.31-0.37). The observed incidence of CF was 1 in 2,203, still Europe’s highest. Of the six undetected cases, most were of Asian ethnicity, suggesting panel limitations for diverse ethnicities.The Irish NBSCF programme exceeded ECFS standards. Most false negatives were caused by CFTR mutations undetected by the genetic panel. Increasing the size of the genetic panel increases detection of CFSPID and carriers and is not currently recommended. Ongoing validity monitoring is vital as the Irish population diversifies. Key messages • The Irish Newborn Screening Programme for Cystic Fibrosis is effective. • Ongoing validity monitoring is vital as the Irish population diversifies.

Prenatal Diagnosis of Cystic Fibrosis by Celocentesis.

Celocentesis is a new sampling tool for prenatal diagnosis available from 7 weeks in case of couples at risk for genetic diseases. In this study, we reported the feasibility of earlier prenatal diagnosis by celocentesis in four cases of cystic fibrosis and one case of cystic fibrosis and β-thalassemia co-inherited in the same fetus. Celomic fluids were aspired from the celomic cavity between 8+2 and 9+3 weeks of gestation and fetal cells were picked up by micromanipulator. Maternal DNA contamination was tested and target regions of fetal DNA containing parental pathogenetic variants of CFTR and HBB genes were amplified and sequenced. Four of the five fetuses resulted as being affected by cystic fibrosis and, in all cases, the women decided to interrupt the pregnancy. In the other case, the fetus presented a healthy carrier of cystic fibrosis. The results were confirmed in three cases on placental tissue. In one case, no abortive tissue was obtained. In the last case, the woman refused the prenatal diagnosis to confirm the celocentesis data; the pregnancy is ongoing without complications. This procedure provides prenatal diagnosis of monogenic diseases at least four weeks earlier than traditional procedures, reducing the anxiety of patients and providing the option for medical termination of the affected fetus at 8-10 weeks of gestation, which is less traumatic and safer than surgical termination in the second trimester.

Genetic counseling access and service delivery in New York State is variable for parents of infants with complex CFTR genotypes conferring uncertain phenotypes.

New York State (NYS) utilizes a three-tiered cystic fibrosis newborn screening (CFNBS) algorithm that includes cystic fibrosis transmembrane conductance regulator (CFTR) gene sequencing. Infants with >1 CFTR variant of potential clinical relevance, including variants of uncertain significance or varying clinical consequence are referred for diagnostic evaluation at NYS cystic fibrosis(CF) Specialty Care Centers (SCCs). As part of ongoing quality improvement efforts, demographic, screening, diagnostic, and clinical data were evaluated for 289 CFNBS-positive infants identified in NYS between December 2017 and November 2020 who did not meet diagnostic criteria for CF and were classified as either: CFTR-related metabolic syndrome/CF screen positive, inconclusive diagnosis (CRMS/CFSPID) or CF carriers. Overall, 194/289 (67.1%) had CFTR phasing to confirm whether the infant's CFTR variants were in cis or in trans. Eighteen complex alleles were identified in cis; known haplotypes (p.R117H+5T, p.F508del+p.L467F, and p.R74W+p.D1270N) were the most common identified. Thirty-twoinfants (16.5%) with all variants in cis were reclassified as CF carriers rather than CRMS/CFSPID. Among 263 infants evaluated at anNYS SCC, 70.3% were reported as having received genetic counseling about their results by any provider, with 96/263 (36.5%) counseled by a certified genetic counselor. Given the particularly complex genetic interpretation of results generated by CFNBS algorithms including sequencing analysis, additional efforts are needed to ensure families of infants with a positive CFNBS result have CFTR phasing when needed to distinguish carriers from infants with CRMS/CFSPID, and access to genetic counseling to address implications of CFNBS results.

Cystic fibrosis carrier screening: a 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.

Atraumatic Splenic Rupture in a Neonate: A Case Report

Idiopathic atraumatic splenic rupture (ASR) is rare, especially in neonates and can result in the spontaneous hemorrhage of the organ, abdominal distension, and hemoperitoneum. This condition can be fatal without prompt diagnosis and surgical intervention. The pathophysiology of ASR is difficult to understand due to its rarity; however, retrospective reviews have found an association with neoplasm, infection, inflammatory diseases, and anticoagulant drugs. Therefore, it is essential to report this rare occurrence. This case report involves a 2-day-old neonate born to a mother with chronic hypertension, chorioamnionitis, and a carrier of cystic fibrosis. An abdominal sonogram followed by contrast-enhanced computed tomography (CT) revealed hemoperitoneum with possible active bleeding and lack of definite visualization of the spleen. During emergency laparotomy, the attempt to preserve the organ was unsuccessful, requiring splenectomy. The neonate recovered well from the procedure and was discharged on the 18th day of life.

Outcome data from 15 years of cystic fibrosis newborn screening in a large UK region

BackgroundThe West Midlands Newborn Bloodspot Screening Laboratory is one of 16 in the UK and serves two tertiary paediatric cystic fibrosis (CF) centres (Staffordshire Children’s Hospital at Royal Stoke and...

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

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 CFtrained 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. 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 10families and interviews were coded for emerging themes. During the 4years 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). 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.

Next-Generation Sequencing for Screening Analysis of Cystic Fibrosis: Spectrum and Novel Variants in a South-Central Italian Cohort.

The incidence of cystic fibrosis (CF) and the spectrum of cystic fibrosis transmembrane conductance regulator (CFTR) gene variants differ among geographic regions. Differences in CF carrier distribution are also reported among Italian regions. We described the spectrum of the CFTR variants observed in a large group of subjects belonging from central-southern Italy. We also provide a predictive evaluation of the novel variants identified. CFTR screening was performed in a south-central Italian cohort of 770 subjects. We adopted a next-generation sequencing (NGS) approach using the Devyser CFTR NGS kit on the Illumina MiSeq System coupled with Amplicon Suite data analysis. Bioinformatics evaluation of the impact of novel variants was described. Overall, the presence of at least one alternative allele in the CFTR gene was recorded for 23% of the subjects, with a carrier frequency of CF pathogenic variants of 1:12. The largest sub-group corresponded to the heterozygous carriers of a variant with a conflicting interpretation of pathogenicity. The common CFTR p.(Phe508del) pathogenic variants were identified in 37% of mutated subjects. Bioinformatics prediction supported a potential damaging effect for the three novel CFTR variants identified: p.(Leu1187Phe), p.(Pro22Thr), and c.744-3C > G. NGS applied to CF screening had the benefit of: effectively identifying asymptomatic carriers. It lies in a wide overview of CFTR variants and gives a comprehensive picture of the carrier prevalence. The identification of a high number of unclassified variants may represent a challenge whilst at the same time being of interest and relevance for clinicians.

Immunoreactive Trypsinogen in Infants Born to Women with Cystic Fibrosis Taking Elexacaftor–Tezacaftor–Ivacaftor

Most people with cystic fibrosis (CF) are diagnosed following abnormal newborn screening (NBS), which begins with measurement of immunoreactive trypsinogen (IRT) values. A case report found low concentrations of IRT in an infant with CF exposed to the CF transmembrane conductance regulator (CFTR) modulator, elexacaftor-tezacaftor-ivacaftor (ETI), in utero. However, IRT values in infants born to mothers taking ETI have not been systematically assessed. We hypothesized that ETI-exposed infants have lower IRT values than newborns with CF, CFTR-related metabolic syndrome/CF screen positive, inconclusive diagnosis (CRMS/CFSPID), or CF carriers. IRT values were collected from infants born in Indiana between 1 January 2020, and 2 June 2022, with ≥1 CFTR mutation. IRT values were compared to infants born to mothers with CF taking ETI followed at our institution. Compared to infants identified with CF (n = 51), CRMS/CFSPID (n = 21), and CF carriers (n = 489), ETI-exposed infants (n = 19) had lower IRT values (p < 0.001). Infants with normal NBS results for CF had similar median (interquartile range) IRT values, 22.5 (16.8, 30.6) ng/mL, as ETI-exposed infants, 18.9 (15.2, 26.5). IRT values from ETI-exposed infants were lower than for infants with abnormal NBS for CF. We recommend that NBS programs consider performing CFTR variant analysis for all ETI-exposed infants.

Efficacia dello screening preconcezionale del portatore di fibrosi cistica: revisione sistematica.

genetic testing for cystic fibrosis (CF) has been offered to people with higher risk of being carrier. to assess the effectiveness of population-based CF carrier screening for adults of reproductive age and its optimal organizational features. systematic review. 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. attitude to screening, uptake of screening offered, informed reproductive choices. 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. 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.

Prevalence and Phenotype of Food Allergy in Cystic Fibrosis

Cystic Fibrosis (CF) patients may present with food-associated gastrointestinal symptoms similar to those seen in food allergy (FA). Minimizing food restrictions is a priority for these patients to optimize overall nutrition. However, there is a gap in knowledge about the prevalence and phenotype of FA in CF patients and CF carriers in the United States.

Immunoreactive Trypsinogen Levels in Infants Born to Women with Cystic Fibrosis Taking Elexacaftor-Tezacaftor-Ivacaftor

Background/Objective:Cystic Fibrosis (CF) is a lethal autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene affecting people of every race and ethnicity in the US. Highly effective modulator therapies (HEMT), such as elexacaftor-tezacaftor-ivacaftor (ETI), correct misfolding and/or improve functioning of the abnormal CFTR protein to lessen disease severity. Most people with CF are diagnosed following abnormal newborn screening (NBS), which involves measuring levels of immunoreactive trypsinogen (IRT). There have been case reports of falsely low IRT levels among infants with CF exposed to ETI in utero, but an overall assessment of IRT levels among these infants has not been conducted. We hypothesize that infants born to mothers with CF taking ETI (ETI-exposed) may have lower IRT levels than newborns with CF, CFTR-related metabolic syndrome (CRMS), or CF carriers.Methods:NBS data from infants born between 2020-22 in Indiana with at least one CFTR mutation were collected and compared to infants born to mothers with CF taking ETI followed at Indiana University, regardless of CFTR mutation status. Infants were categorized as: CF, CRMS, Carrier, ETI-exposed, and Unknown (i.e., diagnosis not determined). An ANOVA test was performed on log-transformed data, with p-values adjusted for Dunnett’s to compare IRT levels of infant groups to ETI-exposed group.Results:There were 51 children with CF, 21 with CRMS, 489 CF carriers, and 19 ETI-exposed infants. Compared to other groups, ETI-exposed infants had a lower median IRT value and IQR (p&lt;0.0001). To our knowledge, there are no CF diagnoses among ETI-exposed infants.Conclusion:IRT levels for ETI-exposed infants, who are obligate CF carriers, were lower than for other infants with CF-related diagnoses, raising the likelihood of false normal NBS results. ETI-exposed infants should have CFTR mutation analysis performed to correctly categorize them as CF, CRMS, or CF carriers.

International experience in the primary prevention of cystic fibrosis (part two)

This text is a continuation of a review of international studies and guidelines/recommendations for primary prevention of cystic fibrosis (CF). This section reviews the selection of pathogenic variants for different CF mutation carrier screening programmes to form panels, taking into account the geographical and ethnic characteristics of the couples being screened, describes the monitoring of couples at intermediate risk of carrier, presents the relationship between carrier screening and neonatal screening, highlights the importance of timely information, including medical and genetic counselling for stakeholders, taking into account the psychosocial status. Separately, we present studies that have found a reduction in the rate of CF births in France, Italy and Israel after the introduction of CF carrier screening.

Abstract A031: Heterozygote carriers of cystic fibrosis mutations have increased risk of colorectal cancer

Abstract Background and purpose: Colorectal cancer (CRC) is the third leading cause of cancer deaths in the U.S. Establishing new genetic variants associated with CRC risk may lead to early CRC detection and novel treatment options. Recently, mouse genetic studies identified the cystic fibrosis transmembrane conductance regulator (CFTR) gene as a tumor suppressor in CRC. In line with this, a human study using MarketScan claims data showed that cystic fibrosis (CF) carriers – individuals with one copy of mutant CFTR – are at increased CRC risk. Although there are more than 10 million CF carriers in the U.S., to our knowledge, no studies comprehensively examined CFTR mutations in relation to CRC risk. Our hypothesis is that CFTR mutations are associated with an increased risk of CRC. Methods: We used whole exome sequencing (WES) data in 454,333 individuals (age 44-82 years), including 4,975 cases of CRC, in the UK Biobank study. We utilized risk set sampling to select up to four controls per CRC case based on age of diagnosis, gender, race, and year of joining the study. To examine associations between CFTR mutations and CRC risk, logistic regression (odds ratio and p-value) was used after adjusting for age, gender and 10 principal components capturing global ancestry. An aggregate burden score was constructed that included all variants listed as CF-causing in the CFTR2 online database. Results: Of the 465 CFTR variants in the CFTR2 database, 378 are classified as CF-causing, and of those 153 were observed in the UK Biobank WES data set. Individuals with two CF-causing alleles were excluded from further analysis (8 cases and 35 controls), since the association between CF and CRC is already well established. The frequency of the F508del variant, the most common CF-causing mutation, was 3.77% in cases versus 3.11% in controls, while the frequency of any other CF-causing mutation was 1.07% in cases versus 0.80% in controls. Having any CF-causing mutation was associated with a significant 24% increased CRC risk (one-sided p=0.002). Having one copy of the F508del mutation, was associated with a significant 21% increased risk of CRC (one-sided p=0.012), while having one copy of any other CF-causing mutation was associated with a slightly larger 34% increased risk of CRC (one-sided p=0.036). Conclusions: CF-causing mutations in the heterozygous state lead to a significantly increased risk of CRC. Individuals with multiple genetic risk factors, such as in CFTR, may require earlier screening for CRC. Citation Format: Anna E. Prizment, Abigail Standafer, Shuo Wang, Conghui Qu, Ulrike Peters, Patricia Scott, Timothy Starr, Nathan Pankratz. Heterozygote carriers of cystic fibrosis mutations have increased risk of colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr A031.

Guidelines for Cystic Fibrosis Carrier Screening in the Prenatal/Preconception Period.

Cystic fibrosis (CF) is one of the most common autosomal recessive disorders. Carrier screening for CF should be offered to all women considering becoming pregnant or who are pregnant. Understanding the available screening tests, their limitations, and the benefits of screening is of paramount importance to the obstetrician-gynecologist. The objective is to review the current guidelines for CF carrier screening including the options for carrier screening, the potential complexities associated with carrier screening for CF, and indications for referral to certified genetic counselors or maternal-fetal medicine specialists. A MEDLINE search of "cystic fibrosis," "cystic fibrosis carrier screening pregnancy," and "inheritance of cystic fibrosis" in the review was performed. The evidence cited in this review includes 2 medical society committee opinions and 15 additional peer-reviewed journal articles that were original research or expert opinion summaries. The American College of Obstetricians and Gynecologists recommends that obstetricians offer CF carrier screening to all pregnant women or women considering becoming pregnant. Based on recent guidelines from ACMG, additional expanded carrier screening can be recommended to patients in the future, with additional CF variants and other autosomal or X-linked recessive conditions. It is important for the prenatal care provider to understand the guidelines for carrier screening as well as the potential complexities associated with carrier screening due to the multiple pathogenic variants in the CFTR gene that may be associated with varying phenotypes. With the options for CF carrier screening, screening performance in different populations, a basic understanding of the disease and interpretation of carrier screening results is of paramount importance to the prenatal care provider.

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.

P-548 IMPORTANCE OF EXPANDED CARRIER SCREENING AMONG OOCYTE DONORS - questions and concerns

Abstract Study question To examine the utility of a range of expanded screening panels for oocyte donors. Summary answer Expanded carrier screening with NGS data identified that 86% of gamete donors were carriers of at least one condition while 302 genes were tested. What is known already The level of genetic testing for oocyte donors is not regulated in most countries. The use of expanded carrier screening is recommended more widely. If the egg donor is a carrier, there is a 50% chance that the offspring will also be carriers. Expanded carrier screening is performed to determine the potential effects of positive carrier status, which guarantees safety for future pregnancy. From practical experience, more genes are tested for a donor, more potential mutations are detected. Study design, size, duration A cohort of 92 potential oocyte donor applicants aged 18-30 years old, who were qualified for oocyte donation after full screening, tested negative on an initial cystic fibrosis carrier test for 11 most common CFTR mutations (PCR panel), was further screened with expanded commercial carrier testing panel (302 genes) using next-generation sequencing (NGS) data. Participants/materials, setting, methods A cohort of 92 potential oocyte donor applicants aged 18-30 years old, who tested negative on an initial cystic fibrosis carrier test for 11 most common CFTR mutations (PCR panel), was further screened with expanded commercial carrier testing panel (302 genes) using next-generation sequencing (NGS) data. Main results and the role of chance Genotyping results for all donors were analyzed; 38% (35/92) of donors were identified as carriers for one condition, 34% (31/92)- for two conditions, 7% (6/92)- for three conditions and 7% (6/92)- for four conditions, including cystic fibrosis. Among the most prevalent conditions in our study were: Hemochromatosis: Type 1: HFE Related- 22%, Cystic Fibrosis: CFTR-related conditions 11%, Biotinidase deficiency– 7,6%, 21-Hydroxilase-Deficient Congenital Nonclassical Adrenal Hyperplasia- 6,5%, Krabbe disease – 6,5%, Usher syndrome: USH2A-related conditions – 6,5%, Nonsyndromic deafness: GJB2- related conditions- 5,4% and Smith-Lemli-Opitz syndrome (5,4%). Limitations, reasons for caution Each donor was consented for genetic testing Wider implications of the findings This study shows a need to provide the explicit requirement for oocyte donor genetic testing and guidelines to satisfy quality and safety and not reduce the number of donors carries of mutations, but to implement a practice of genetic matching. Trial registration number not applicable

Geographical distribution of cystic fibrosis carriers as population genetic determinant of COVID-19 spread and fatality in 37 countries

COVID-19 has shown a relevant heterogeneity in spread and fatality among countries together with a significant variability in its clinical presentation, indicating that host genetic factors may influence COVID-19 pathogenicity. Indeed, subjects carrying single pathogenic variants of the Cystic Fibrosis (CF) Transmembrane Conductance Regulator (CFTR) gene – i.e. CF carriers – are more susceptible to respiratory tract infections and are more likely to undergo severe COVID-19 with higher risk of 14-day mortality.Given that CF carrier prevalence varies among ethnicities and nations, an ecological study in 37 countries was conducted, in order to determine to what extent the diverse CF carrier geographical distribution may have affected COVID-19 spread and fatality during the first pandemic wave.The CF prevalence in countries, as indicator of the geographical distribution of CF carriers, significantly correlated in a direct manner with both COVID-19 prevalence and its Case Fatality Rate (CFR). In a regression study weighted for the number of tests performed, COVID-19 prevalence positively correlated with CF prevalence, while CFR correlated with population percentage older than 65-year, cancer and CF prevalence. Multivariate regression model also confirmed COVID-19 CFR to be associated with CF prevalence, after adjusting for elderly, cancer prevalence, and weighting for the number of tests performed.This study suggests a putative contribution of population genetics of CFTR in understanding the spatial distribution of COVID-19 spread and fatality.

A spectrum of recessiveness among Mendelian disease variants in UK Biobank

Recent work has found increasing evidence of mitigated, incompletely penetrant phenotypes in heterozygous carriers of recessive Mendelian disease variants. We leveraged whole-exome imputation within the full UK Biobank cohort (n ∼ 500K) to extend such analyses to 3,475 rare variants curated from ClinVar and OMIM. Testing these variants for association with 58 quantitative traits yielded 102 significant associations involving variants previously implicated in 34 different diseases. Notable examples included a POR missense variant implicated in Antley-Bixler syndrome that associated with a 1.76 (SE 0.27) cm increase in height and an ABCA3 missense variant implicated in interstitial lung disease that associated with reduced FEV1/FVC ratio. Association analyses with 1,134 disease traits yielded five additional variant-disease associations. We also observed contrasting levels of recessiveness between two more-common, classical Mendelian diseases. Carriers of cystic fibrosis variants exhibited increased risk of several mitigated disease phenotypes, whereas carriers of spinal muscular atrophy alleles showed no evidence of altered phenotypes. Incomplete penetrance of cystic fibrosis carrier phenotypes did not appear to be mediated by common allelic variation on the functional haplotype. Our results show that many disease-associated recessive variants can produce mitigated phenotypes in heterozygous carriers and motivate further work exploring penetrance mechanisms.

Cystic Fibrosis assessment in infertile couples: genetic analysis trough the Next Generation Sequencing technique

Background: Cystic Fibrosis (CF) is a genetic disease which is responsible for different systemic conditions. In particular, CF could be responsible for infertility, especially in the male partner due to congenital bilateral absence of vas deferens (CBAVD). Moreover, in Assisted Reproductive Techniques CF screening is performed in order to detect possible risks for the newborn. For this reason, CF testing is one of the main genetic screening performed in infertile couples. Methods: In this scenario, we present a prospective observational study in CF testing with Next Generation Sequencing (NGS) technique on 360 subjects referring to an In-Vitro Fertilization center. Results: 360 subjects were screened for CFTR. Of them, 19 subjects presented CF causing variants, 44 subjects presented CFTR-RD associated, 22 subjects had variants of uncertain significance and 19 subjects with no clinical consequences. Conclusion: Results clarify proportions of the main CF mutations. Actually, there are no more advanced techniques rather than Next Generation Sequencing (NGS) technique, although it is not yet widely used as a test for the identification of the CF carrier.