International Perspectives of Extended Genetic Sequencing When Used as Part of Newborn Screening to Identify Cystic Fibrosis.

There is increasing interest in using extended genetic sequencing (EGS) in newborn screening (NBS) for cystic fibrosis (CF). How this is implemented will change the number of children being given an uncertain outcome of CRMS/CFSPID (cystic fibrosis transmembrane conductance regulator (CFTR)-related metabolic syndrome/CF Screen Positive Inconclusive Diagnosis), probable carrier results, and the number of missed CF diagnoses. An international survey of CF health professionals was used to gather views on two approaches to EGS-specific (may reduce detection of CRMS/CFSID but miss some CF cases) versus sensitive (may increase detection of CRMS/CFSPID but avoid missing more CF cases). Health professionals acknowledged the anxiety caused to parents (and health professionals) from the uncertainty surrounding the prognosis and management of CRMS/CFSPID. However, most preferred the sensitive approach, as overall, identifying more cases of CRMS/CFSPID was viewed as less physically and psychologically damaging than a missed case of CF. The importance of early diagnosis and treatment for CF to ensure better health outcomes and reducing diagnostic odysseys for parents were highlighted. A potential benefit to identifying more children with CRMS/CFSPID included increasing knowledge to obtain a better understanding of how these children should best be managed in the future.

ECFS standards of care on CFTR-related disorders: Towards a comprehensive program for affected individuals.

After three publications defining an updated guidance on the diagnostic criteria for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (pwCFTR-RDs), establishing its relationship to CFTR-dysfunction and describing the individual disorders, this fourth and last paper in the series addresses some critical challenges facing health care providers and pwCFTR-RD. Topics included are: 1) benefits and obstacles to collect data from pwCFTR-RD are discussed, together with the opportunity to integrate them into established CF-registries; 2) the potential of infants designated CRMS/CFSPID to develop a CFTR-RD and how to communicate this information; 3) a description of the challenges in genetic counseling, with particular regard to phenotypic variability, unknown long-term evolution, CFTR testing and pregnancy termination 4) a proposal for the assessment of potential barriers to the implementation and dissemination of the produced documents to health care professionals involved in the care of pwCFTR-RD and a process to monitor the implementation of the CFTR-RD recommendations; 5) clinical trials investigating the efficacy of CFTR modulators in CFTR-RD and how endpoints and outcomes might be adapted to the heterogeneity of these disorders.

Stakeholder Views of the Proposed Introduction of Next Generation Sequencing into the Cystic Fibrosis Screening Protocol in England.

The project aimed to gather, analyse, and compare the views of stakeholders about the proposed UK cystic fibrosis (CF) screening protocol incorporating next generation sequencing (NGS). The study design was based on principles of Q-methodology with a willingness-to-pay exercise. Participants were recruited from 12 CF centres in the UK. The study contained twenty-eight adults who have experience with CF (parents of children with CF (n = 21), including parents of children with CF transmembrane conductance regulator (CFTR)-related metabolic syndrome (CRMS)/CF screen positive-inconclusive diagnosis (CFSPID), an uncertain outcome (n = 3), and adults with CF (n = 4)), and nine health professionals involved in caring for children with CF. Parents and health professionals expressed a preference for a sensitive approach to NGS. This was influenced by the importance participants placed on not missing any children with CF via screening and the balance of harm between missing a case of CF compared to picking up more children with an uncertain outcome (CRMS/CFSPID). Given the preference for a sensitive approach, the need for adequate explanations about potential outcomes including uncertainty (CFSPID) at the time of screening was emphasized. More research is needed to inform definitive guidelines for managing children with an uncertain outcome following CF screening.

Standards for the care of people with cystic fibrosis (CF): A timely and accurate diagnosis.

There is considerable activity with respect to diagnosis in the field of cystic fibrosis (CF). This relates primarily to developments in newborn bloodspot screening (NBS), more extensive gene analysis and improved characterisation of CFTR-related disorder (CFTR-RD). This is particularly pertinent with respect to accessibility to variant-specific therapy (VST), a transformational intervention for people with CF with eligible CFTR gene variants. This advance reinforces the need for a timely and accurate diagnosis. In the future, there is potential for trials to assess effectiveness of variant-specific therapy for CFTR-RD. The guidance in this paper reaffirms previous standards, clarifies a number of issues, and integrates emerging evidence. Timely and accurate diagnosis has never been more important for people with CF.

Children with cystic fibrosis are still receiving inconclusive diagnosis despite undergoing newborn screening.

AIM: We aimed to familiarise clinicians with the terms cystic fibrosis transmembrane conductance regulator related metabolic syndrome (CRMS) and cystic fibrosis screen positive inconclusive diagnosis (CFSPID). We also sought to highlight the monitoring and outcomes of children that match these designations. METHODS: A literature review was performed by searching PubMed from its inception until 30 November 2022. All relevant articles were included in this narrative review. RESULTS: Despite the implementation of newborn screening programmes for cystic fibrosis (CF), the diagnosis remains uncertain in some newborn infants with elevated immunoreactive trypsinogen. In 2016, a unified definition for CRMS/CFSPID was established to categorise these children. While many of them remain healthy, a portion of these children may develop CF. As a result, it is crucial to monitor them regularly. CONCLUSION: CRMS/CFSPID is a designation and not a diagnosis. Longer longitudinal studies are needed to shed light on the most appropriate follow-up of these children. Paediatricians need to be knowledgeable about this condition in order to administer proper care, and children should be in contact with their local CF centre.

Comparison between Gibson-Cooke and Macroduct Methods in the Cystic Fibrosis Neonatal Screening Program and in Subjects Who Are Cystic Fibrosis Screen-Positive with an Inconclusive Diagnosis.

The sweat test (ST) is the current diagnostic gold standard for cystic fibrosis (CF). Many CF centres have switched from the Gibson-Cooke method to the Macroduct system-based method. We used these methods simultaneously to compare CF screening outcomes. STs using both methods were performed simultaneously between March and December 2022 at CF Centre in Florence. We included newborns who underwent newborn bloodspot screening (NBS), newborns undergoing transfusion immediately after birth, and children with CF screen-positive, inconclusive diagnosis (CFSPID). We assessed 72 subjects (median age 4.4 months; range 0-76.7): 30 (41.7%) NBS-positive, 18 (25.0%) newborns who underwent transfusion, and 24 (33.3%) children with CFSPID. No significant differences were found between valid sample numbers, by patient ages and groups (p = 0.10) and between chloride concentrations (p = 0.13), except for sweat chloride (SC) measured by the Gibson-Cooke and Macroduct methods in CFSPID group (29.0, IQR: 20.0-48.0 and 22.5, IQR: 15.5-30.8, respectively; p = 0.01). The Macroduct and Gibson-Cooke methods showed substantial agreement with the SC values, except for CFSPID, whose result may depend on the method of sweat collection. In case of invalid values with Macroduct, the test should be repeated with Gibson-Cooke method.

Different management approaches and outcome for infants with an inconclusive diagnosis following newborn screening for cystic fibrosis (CRMS/CFSPID) and Pseudomonas aeruginosa isolation.

INTRODUCTION: Evidence is currently lacking to guide the management of cystic fibrosis (CF) transmembrane conductance regulator-related metabolic syndrome CF screen-positive inconclusive diagnosis (CRMS/CFSPID) with Pseudomonas aeruginosa (Pa)-positive respiratory culture. This study assessed the clinical data, management, and outcomes of an Italian cohort of CRMS/CFSPID infants with Pa isolated from their airways. METHODS: Data of Pa-positive CRMS/CFSPID infants born between January 2011 and August 2018 and followed at five CF Italian centres were retrospectively extracted. Further data were collected until June 2021 to assess outcomes, prevalence of subjects treated with antimicrobials, and treatment type and duration. RESULTS: Forty-three asymptomatic CRMS/CFSPID patients (median age on 30 June 2021, 82 months; interquartile range [IQR], 63-98 months) with at least one positive airway culture for non-mucoid Pa (median age at first isolation, 18.7 months; IQR, 7-25 months) were enrolled. Of them, 24 (55.8%) underwent anti-Pa therapy. Pa clearance occurred in 22 (91.6%) of 24 patients versus spontaneous clearance in 16 of 19 (84.2%) untreated patients (chi-square, 0.5737; p = 0.44878). After a median follow-up of 6.2 years (IQR, 3.0-9.9), 7 (16.3%) were diagnosed with CF after a pathological sweat test (median age, 43 months; IQR, 28-77 months), 3 (7%) developed recurrent pancreatitis or isolated bronchiectasis consistent with CFTR-related disorder, and the CRMS/CFSPID classification remained in 33 (76.7%). CONCLUSIONS: Pa detection frequently occurs in asymptomatic infants with CRMS/CFSPID but tends to clear spontaneously. More studies are needed to determine if Pa isolation can predict evolution.

High rates of anxiety detected in mothers of children with inconclusive cystic fibrosis screening results.

OBJECTIVE: The purpose was to assess postpartum depression, anxiety, and depression in mothers of children with an inconclusive diagnosis after a positive cystic fibrosis (CF) newborn screening (NBS), known as cystic fibrosis transmembrane conductance regulator (CFTR)-related metabolic syndrome (CRMS) or CF screen positive, inconclusive diagnosis (CFSPID). There is limited information on the prognosis and on the impact of this designation on maternal mental health. METHODS: Mothers of children with CRMS/CFSPID and CF identified by NBS were recruited from two centers in California. Maternal mental health was assessed using measures of depression, anxiety, and a scripted interview. Descriptive statistics and multivariate logistic regression were applied for data reporting. RESULTS: A total of 109 mothers were recruited: CF: 51, CRMS/CFSPID: 58. Mothers from both groups showed higher rates of depression and anxiety symptoms than women in the general population. CRMS/CFSPID and CF mothers had no significant difference on their self-reported symptoms of anxiety and depression after adjusting for potential confounders. Mothers equally reported that their child's diagnosis had a negative impact, and that genetic counseling had a positive impact on their emotional health. CONCLUSIONS: CF and CRMS/CFSPID diagnoses impact maternal mental health similarly. Uncertain prognosis of CRMS/CFSPID likely contributed to the negative mental health impact. Providers should consider conducting mental health screening for every mother of a child with CRMS/CFSPID, in addition to the recommended mental health screening for mothers of children with CF. Genetic counseling has potential to mitigate emotional stress on these families.

Non-pulmonary CFTR-related symptom improvement with ivacaftor in p.Phe508del/p.Arg117His (7T) cystic fibrosis.

Diagnosis and management of CRMS/CFSPID and cystic fibrosis (CF) with mild phenotypes remains challenging, and this extends to expanding practice with the use of CFTR modulators. We describe a case of an 18-year-old man with p.F508del/p.Arg117His(7T) initially presenting with CRMS/CFSPID. He went on to be diagnosed with pancreatic sufficient CF with minimal lung disease. However, he has had significant CFTR-related symptoms with recurrent pancreatitis and chronic sinusitis. These non-pulmonary symptoms resolved following introduction of the CFTR modulator ivacaftor. Care for those with mild CF phenotypes, CRMS/CFSPID and those with CFTR-RD must be individualized, and open dialogue, education and patient centred care is necessary to ascertaining which patients might benefit from management in a multidisciplinary CF clinic and treatment. There may be a role for expanding the use of CFTR modulators to include non-pulmonary manifestations of CFTR dysfunction in some cases.

Detection of disease-causing CFTR variants in state newborn screening programs.

BACKGROUND: Newborn screening (NBS) algorithms for cystic fibrosis (CF) vary in the United State of America and include different cystic fibrosis transmembrane conductance regulator (CFTR) variants. CFTR variant distribution varies among racial and ethnic groups. OBJECTIVE: Our objectives were to identify differences in detection rate by race and ethnicity for CFTR variant panels, identify each US state detection rate for CFTR variant panels, and describe the rate of false-negative NBS and delayed diagnoses by race and ethnicity. METHODS: This is a cross-sectional analysis of the detection rate of at least 1 CFTR variant for seven panels by race and ethnicity in genotyped people with CF (PwCF) or CFTR-related metabolic syndrome (CRMS)/CFTR-related disorders in CF Foundation Patient Registry (CFFPR) in 2020. We estimated the case detection rate of CFTR variant panels by applying the detection rate to Census data. Using data from CFFPR, we compared the rate of delayed diagnosis or false-negative NBS by race and ethnicity. RESULTS: For all panels, detection of at least 1 CFTR variant was highest in non-Hispanic White PwCF (87.5%-97.0%), and lowest in Black, Asian, and Hispanic PwCF (41.9%-93.1%). Detection of at least 1 CFTR variant was lowest in Black and Asian people with CRMS/CFTR-related disorders (48.4%-64.8%). States with increased racial and ethnic diversity have lower detection rates for all panels. Overall, 3.8% PwCF had a false-negative NBS and 11.8% had a delayed diagnosis; Black, Hispanic, and mixed-race PwCF were overrepresented. CONCLUSION: CFTR variant panels have lower detection rates in minoritized racial and ethnic groups leading to false-negative NBS, delayed diagnosis, and likely health disparities.

Clinical outcomes of a large cohort of individuals with the F508del/5T;TG12 CFTR genotype.

BACKGROUND: In recent years, patients with cystic fibrosis (CF) conductance regulator (CFTR) variant poly(T) sequences have been increasingly reported with a wide spectrum of clinical severity. We describe the long-term clinical outcomes and progression to a CF diagnosis over time in a large Italian cohort of patients carrying the CFTR F508del/5T;TG12 genotype. METHODS: A retrospective analysis of subjects from 10 CF centres in Italy with the F508del/5T;TG12 genotype was performed. Demographic, clinical, microbiological, and biochemical data, as well as information about the follow-ups and complications of the enroled patients, were collected. RESULTS: A total of 129 subjects (54 females; median age: 15.0 years, range: 0-58 years; 59 older than 18 years) were included. In terms of initial diagnoses, 30 were CF (23.3%), 41 were CFTR-related disorder (CFTR-RD) (31.7%), and 58 were CF transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen positive, inconclusive diagnosis (CRMS/CFSPID) (45.0%). After a median follow-up of 6.7 years (range 0.2-25 years), 15 patients progressed to CF, bringing the total number of CF diagnoses to 45/129 (34.9%). Most of these patients had mild lung diseases with pancreatic sufficiency and a low prevalence of CF-related complications. CONCLUSIONS: At the end of the study, 34.9% of subjects with the CFTR F508del/5T;TG12 genotype were diagnosed with CF. We suggest including patients with the F508del/5T;TG12 genotype in long-term follow-ups.

Genetic counseling access for parents of newborns who screen positive for cystic fibrosis: Consensus guidelines.

INTRODUCTION: A risk associated with cystic fibrosis newborn screening (CFNBS) is parental misunderstanding of genetic information generated by the over 6600 positive screens reported annually in the United States. CFNBS algorithms incorporating DNA analysis can generate genetic information that requires clinical interpretation and has significance for the newborn, parents, and other relatives. Engagement between CF care centers and trained genetic counseling providers, such as licensed and/or certified genetic counselors (GCs), is variable and limited in providing information to CFNBS positive (CFNBS+) families. METHODS: Using a modified Delphi process, a workgroup of CFNBS experts developed recommendation statements for engagement of genetic counseling services in CF care centers where CFNBS + diagnostic evaluations are performed. Statements were assessed over three rounds of surveys, one face-to-face meeting, and through public feedback. RESULTS: Seventeen statements achieved >80% consensus (range: 82%-100%). The workgroup affirmed prior CFF policy statements recommending genetic counseling for parents of infants with CFNBS+. The remaining statements addressed infrastructure and logistics of genetic counseling services, including defining appropriate training for genetic counseling providers and counseling content, establishing a path to equal access to genetic counseling providers across CF care centers, and setting a standard for client-centered CFNBS genetic counseling that is respectful of diverse patient needs and autonomy. CONCLUSIONS: Implementation of client-centered genetic counseling for CFNBS+ families in CF care centers by providers with expertise in both CF and genetic counseling will require efforts to further define core concepts, enhance the education of providers, and develop opportunities for access via telemedicine.

Practice variation of genetic counselor engagement in the cystic fibrosis newborn screen-positive diagnostic resolution process.

Families of infants with a positive newborn screen for cystic fibrosis (CFNBS+) have well-characterized genetic counseling needs, including understanding the implications of diagnostic categorization. However, degree of involvement of genetic counselors (GCs) in the CFNBS+ diagnostic resolution process varies. This project explored GC engagement with US CF care centers in the diagnostic resolution process for CFNBS+ infants. Surveys were emailed to 713 Cystic Fibrosis Foundation-accredited CF center directors and clinic coordinators and 4,517 GCs. Respondents from institutions providing CFNBS+ diagnostic resolution were categorized by level of engagement between the CF center and GC: GC is part of or embedded in CF center (GC-engaged); GC is independent of CF center but receives CFNBS+ referrals (GC-referral); GC is uninvolved (non-engaged)] in CF center or CFNBS+ diagnostic resolution process. Responses from 125 CF center directors and clinic coordinators (17.5%) and 174 GCs (3.8%) were received. Analysis targeted responses from 84 center directors and clinic coordinators and 52 GCs, estimated to represent 24%-48% and 29% of 175 pediatric CF care centers, respectively. Nearly 40% of CF center directors or clinic coordinators never refer CFNBS+ infants to GCs. Respondents from GC-engaged CF centers reported that GCs provide unique and valuable services, understand CF at a high level, improve efficiency of the CFNBS+ diagnostic resolution process, and should be part of the CF care team; respondents from non-engaged CF centers reported negative views of GCs' value and knowledge (all p < .05). GCs engaged with CF centers were more likely to report that their services were valued by and accessible to CF centers (both p < .05). At all levels of engagement with CF centers, GCs were comfortable discussing CF genotype-phenotype correlation, variants of unknown significance, quality of life, and therapies. These results highlight a need to address practice variation in CFNBS+ genetic counseling and improve access to GCs' services.