Positive Cystic Fibrosis Newborn Screening Research Articles

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.

Gradual increase in sweat chloride concentration is associated with a higher risk of CRMS/CFSPID to CF reclassification.

Universal implementation of cystic fibrosis (CF) newborn screening (NBS) has led to the diagnostic dilemma of infants with CF screen-positive, inconclusive diagnosis (CFSPID), with limited guidance regarding prognosis and standardized care. Rates of reclassification from CFSPID to CF vary and risk factors for reclassification are not well established. We investigated whether clinical characteristics are associated with the risk of reclassification from CFSPID to a CF diagnosis. Children with a positive CF NBS were recruited from two sites in California. Retrospective, longitudinal, and cross-sectional data were collected. A subset of subjects had nasal epithelial cells collected for CF transmembrane conductance regulator(CFTR) functional assessment. Multivariate logistic regression was used to assess the risk of reclassification. A total of 112 children completed the study (CF = 53, CFSPID = 59). Phenotypic characteristics between groups showed differences in pancreatic insufficiency prevalence, immunoreactive trypsinogen (IRT) levels, and Pseudomonas aeruginosa (PSA) colonization. Spirometry measures were not different between groups. Nasal epithelial cells from 10 subjects showed 7%-30% of wild-type (WT)-CFTR (wtCFTR) function in those who reclassified and 27%-67% of wtCFTR function in those who retained the CFSPID designation. Modeling revealed that increasing sweat chloride concentration (sw[Cl- ]) and PSA colonization were independent risk factors for reclassification to CF. Increasing sw[Cl- ] and a history of PSA colonization are associated with the risk of reclassification from CFSPID to CF in a population with high IRT and two CFTR variants. A close follow-up to monitor phenotypic changes remains critical in this population. The role of CFTR functional assays in this population requires further exploration.

Newborn screening for cystic fibrosis: Role of primary care providers in caring for infants with positive screening results.

To explore primary care providers' (PCPs') preferred roles and confidence in caring for infants receiving a positive cystic fibrosis (CF) newborn screening (NBS) result, as well as management of CF family planning issues, given that expanded NBS has resulted in an increase in positive results. Mailed questionnaire. Ontario. Ontario FPs, pediatricians, and midwives identified by Newborn Screening Ontario as having had an infant with a positive CF NBS result in their practice in the previous 6 months. Primary care providers' preferred roles in providing well-baby care for infants with positive CF screening results. Overall, 321 of 628 (51%) completed surveys (208 FPs, 68 pediatricians, 45 midwives). For well-baby care for infants confirmed to have CF, 77% of PCPs indicated they would not provide total care (ie, 68% would share care with other specialists and 9% would refer to specialists completely); for infants with an inconclusive CF diagnosis, 50% of PCPs would provide total care, 45% would provide shared care, and 5% would refer to a specialist; for CF carriers, 89% of PCPs would provide total care, 9% would provide shared care, and 2% would refer. Half (54%) of PCPs were extremely or very confident in providing reassurance about CF carriers' health. Only 25% knew how to order parents' CF carrier testing; 67% knew how to refer for prenatal diagnosis. Confidence in reassuring parents about the health of CF carrier children was associated with providing total well-baby care for CF carriers (risk ratio of 1.50; 95% CI 1.14 to 1.97) and infants with an inconclusive diagnosis (risk ratio of 3.30; 95% CI 1.34 to 8.16). Most PCPs indicated willingness to treat infants with a range of CF NBS results in some capacity. It is concerning that some indicated CF carriers should have specialist involvement and only half were extremely or very confident about reassuring families about carrier status. This raises issues about possible medicalization of those with carrier status, prompting the need for PCP education about genetic disorders and the meaning of genetic test results.

Primary care providers' role in newborn screening result notification for cystic fibrosis.

To explore primary care providers' (PCPs') role in result notification for newborn screening (NBS) for cystic fibrosis (CF), given that expanded NBS has increased the number of positive screening test results, drawing attention to the role of PCPs in supporting families. Cross-sectional survey and qualitative interviews. Ontario. Primary care providers (FPs, pediatricians, and midwives) who received a positive CF NBS result for an infant in their practice in the 6 months before the study. Whether the PCP notified the family of the initial positive CF screening result. Data from 321 PCP surveys (response rate of 51%) are reported, including 208 FPs, 68 pediatricians, and 45 midwives. Interviews were completed with 34 PCPs. Most (65%) surveyed PCPs reported notifying the infant's family of the initial positive screening result; 81% agreed that they have an important role to play in NBS; and 88% said it was important for PCPs, rather than the NBS centre, to notify families of initial positive results. With support and information from NBS centres, 68% would be extremely or very confident in doing so; this dropped to 54% when reflecting on their recent reporting experience. More than half (58%) of all PCPs said written point-of-care information from the NBS centre was the most helpful format. Adjusted for relevant factors, written educational information was associated with a lower rate of notifying families than written plus verbal information (risk ratio of 0.79; 95% CI 0.69 to 0.92). In the interviews, PCPs emphasized the challenge of balancing required content knowledge with the desire for the news to come from a familiar provider. Most PCPs notify families of NBS results and value this role. These data are relevant as NBS programs and other genomic services expand and consider ways of keeping PCPs confident and actively involved.

Sweat Testing and Recent Advances.

Cystic fibrosis (CF) is the most common fatal genetic disease of the Caucasian population. Sweat testing is the principal diagnostic test for CF, and it is used for the evaluation of infants with positive CF newborn screening (NBS) and in patients with clinical findings suggesting CF. This article describes the classical sweat test method in detail and also provides an overwiew of recent advances.

Quantity not sufficient rates and delays in sweat testing in US infants with cystic fibrosis.

Diagnostic sweat testing is required for infants with positive newborn-screening (NBS) tests for cystic fibrosis (CF). Infants have "quantity not sufficient" (QNS) sweat volumes more often than older children. A comprehensive study of QNS sweat volumes in infants has not previously been reported. We surveyed US CF Centers to obtain QNS rates in all infants who had sweat testing at under 14 days and under 3 months of age. We then calculated QNS rates reported to the Cystic Fibrosis Foundation Patient Registry (CFFPR) 2010-2018 in 10-day increments from 1 to 60 days of life. We compared QNS sweat test rates in preterm (<37-weeks gestational age) vs term infants. We assessed age at sweat test and proportion of infants who did not have a sweat test reported by 60 days of age. Thirty-nine of 144 (27%) of CF Centers reported a mean QNS rate of 10.5% (range, 0-100) in infants 14-days-old or younger. CFFPR data showed the highest QNS rates in the youngest infants and in those born before 37 weeks of gestation. The median age at sweat testing decreased over time, but more than 22% of infants did not have a sweat test reported by 60 days. Higher QNS rates are seen in the youngest infants with CF, but more than 80% of infants younger than 2 weeks of age have adequate sweat volumes. Sweat testing should not be delayed in infants with a positive CF NBS test.

Two years of newborn screening for cystic fibrosis in Turkey: Çukurova experience.

Şaşihüseyinoğlu AŞ, Altıntaş DU, Bişgin A, Doğruel D, Yılmaz M, Serbes M. Two years of newborn screening for cystic fibrosis in Turkey: Çukurova experience. Turk J Pediatr 2019; 61: 505-512. The severity of cystic fibrosis (CF) depends on the type of cystic fibrosis transmembrane conductance regulator (CFTR) mutation. The primary goal of newborn screening (NBS) is to decrease morbidity, mortality and associated disabilities. The National NBS for CF programme was initiated in Turkey since 01.01.2015. The aim of this study was to present two years of experience of our CF center which is located in the south of Turkey. The study population comprised of infants who were born in Adana between 1 January 2015 - 31 December 2016, referred to our CF center as part of NBS for CF and performed CFTR gene analysis. The infants were divided into three groups according to laboratory tests and symptoms as CF, CRMS (cystic fibrosis transmembrane conductance regulator-related metabolic syndrome) and false positive NBS. Between January 1, 2015 and December 31, 2016, NBS was performed in 77,437 newborns in Adana. Two hundred seven (0.26%) newborns screened were positive for CF. A total of 184 infants were included to the study. We reported 12 babies as CF with an incidence of 1:6,452. The babies diagnosed as CF constituted 6.5% of positive CF NBS. Rest of study group diagnosed with CRMS/CFSPID (54/184, 29.5%) and false positive (118/184, 64%). Positive predictive value (PPV) of NBS was 6.5%. The most common CFTR mutations were 508del, p.F1052L and p.L997 F. The implementation of CF-NBS program has been successful in Turkey. But it is too early to determine the specificity and sensitivity of the program.

Benign and Deleterious Cystic Fibrosis Transmembrane Conductance Regulator Mutations Identified by Sequencing in Positive Cystic Fibrosis Newborn Screen Children from California.

BackgroundOf the 2007 Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mutations, 202 have been assigned disease liability. California’s racially diverse population, along with CFTR sequencing as part of newborn screening model, provides the opportunity to examine the phenotypes of children with uncategorized mutations to help inform disease liability and penetrance.MethodsWe conducted a retrospective cohort study based on children screened from 2007 to 2011 and followed for two to six years. Newborns that screened positive were divided into three genotype groups: those with two CF-causing mutations (CF-C); those with one mutation of varying clinic consequence (VCC); and those with one mutation of unknown disease liability (Unknown). Sweat chloride tests, pancreatic sufficiency status, and Pseudomonas aeruginosa colonization were compared.ResultsChildren with two CF-causing mutations had a classical CF phenotype, while 5% of VCC (4/78) and 11% of Unknown (27/244) met diagnostic criteria of CF. Children carrying Unknown mutations 2215insG with D836Y, and T1036N had early and classical CF phenotype, while others carrying 1525-42G>A, L320V, L967S, R170H, and 296+28A>G had a benign clinical presentation, suggesting that these are non-CF causing.ConclusionsWhile most infants with VCC and Unknown CFTR mutations do not meet diagnostic criteria for CF, a small proportion do. These findings highlight the range of genotypes and phenotypes in the first few years of life following CF newborn screening when CFTR sequencing is performed.

Benign outcome among positive cystic fibrosis newborn screen children with non-CF-causing variants

BackgroundThe Clinical and Functional Translation of CFTR project (CFTR2) classified some cystic fibrosis transmembrane conductance regulator (CFTR) gene variants as non-cystic fibrosis (CF)-causing. To evaluate this, the clinical status of children carrying these mutations was examined. MethodsWe analyzed CF disease-defining variables over 2–6 years in two groups of California CF screen- positive neonates born from 2007 to 2011: (1) children with two CF-causing variants and (2) children with one CF-causing and one non-CF-causing variant, as defined by CFTR2. ResultsChildren carrying non-CF-causing variants had significantly higher birth weight, lower immunoreactive trypsinogen and sweat chloride values, higher first year growth curves, and a lower rate of persistent Pseudomonas aeruginosa colonization compared to children with two CF-causing variants. ConclusionsThe outcomes in children 2–6 years of age with the L997F, G576A, R1162L, V754M, R668C, R31C, and S1235R variants are consistent with the CFTR2 non-CF-causing classification.

Primary care providers' experiences notifying parents of cystic fibrosis newborn screening results.

This study examines primary care provider (PCP) experiences with the initial parental disclosure of cystic fibrosis (CF) newborn screening (NBS) results in order to identify methods to improve parent-provider communication during the CF NBS process. PCPs of infants who received positive CF NBS results participated in semistructured phone interviews. Interviews were analyzed using a qualitative content analysis. PCPs acknowledged the difficulty of "breaking bad news" to parents, and emphasized minimizing parental anxiety and maximizing parental understanding. PCPs used a variety of methods to notify parents, and shared varying information about the significance of the results. Variation in the method of parental notification, information discussed, and attention to parents' emotional needs may limit successful follow-up of children with positive CF NBS results. A multifaceted intervention to improve PCP knowledge, management, and communication could improve provider confidence, optimize information transfer, and minimize parental distress during the initial disclosure of CF NBS results.

Evaluation of genetic counseling among cystic fibrosis carriers, Michigan Newborn Screening

A quality improvement (QI) strategy to improve the rate of genetic counseling (GC) services was initiated in cystic fibrosis (CF) care Center E in 2010. This statewide study was conducted to determine: (1) GC rates before and after implementation of the QI strategy at Center E; (2) characteristics associated with not receiving GC; and (3) topic areas addressed during GC. The retrospective study included 1,097 CF carriers born from 2008 to 2011 identified through Michigan's Newborn Screening Program. Rate of GC services was determined for Center E and the other four CF centers before and after the QI change. Bivariate and multivariable logistic regression was used to determine associations between select characteristics and not receiving GC. Topic areas discussed during GC sessions were assessed using frequency tables. Rate of GC services in Center E increased from 23% in 2008-2010 to 91% in 2011, while at the other centers approximately 92% received GC services across those years. In 2008-2010, being seen at Center E and black race were significantly associated with increased likelihood of not receiving GC services in adjusted analyses. In 2011, neither characteristic was associated with receipt of GC. Of 16 target topic areas, all were discussed in 85% of GC sessions. Implementing a QI strategy of providing sweat test results at the GC appointment within Center E resulted in more CF carriers receiving comprehensive GC services. Center-specific procedure differences should be assessed to increase rate of GC services following a positive CF newborn screen.

Newborn screening for cystic fibrosis in Alberta: Two years of experience

On April 1, 2007, Alberta became the first province in Canada to introduce cystic fibrosis (CF) to its newborn screening program. The Alberta protocol involves a two-tier algorithm involving an immunoreactive trypsinogen measurement followed by molecular analysis using a CF panel for 39 mutations. Positive screens are followed up with sweat chloride testing and an assessment by a CF specialist. Of the 99,408 newborns screened in Alberta during the first two years of the program, 221 had a positive CF newborn screen. The program subsequently identified and initiated treatment in 31 newborns with CF. A relatively high frequency of the R117H mutation and the M1101K mutation was noted. The M1101K mutation is common in the Hutterite population. The presence of the R117H mutation has created both counselling and management dilemmas. The ability to offer CF transmembrane regulator full sequencing may help resolve diagnostic dilemmas. Counselling and management challenges are created when mutations are mild or of unknown clinical significance.

Cystic fibrosis newborn screening: using experience to optimize the screening algorithm

Newborn screening (NBS) for cystic fibrosis (CF) offers the opportunity for early diagnosis and improved outcomes in patients with CF and has been universally available in the state of Massachusetts since 1999 using an immunoreactive trypsinogen (IRT)-DNA algorithm. Ideally, CF NBS is incorporated as part of an integrated NBS system that allows for comprehensive and coordinated education, laboratory screening, clinical follow-up, and evaluation so that evidence-based data can be used to maximize quality improvements and optimize the screening algorithm. The New England Newborn Screening Program (NENSP) retrospectively analyzed Massachusetts's CF newborn screening data that yielded decisions to eliminate a screen-positive category, maintain the IRT cutoff value that prompts the second tier DNA testing, and communicate CF relative risk to primary care providers (PCPs) based on categorization of positive CF NBS results.

Communications Systems and their Models: Massachusetts Parent Compliance with Recommended Specialty Care after Positive Cystic Fibrosis Newborn Screening Result

To evaluate compliance with recommendations for sweat testing/specialty evaluation and genetic counseling after a positive cystic fibrosis newborn screening (CF NBS) result. All infants with positive CF NBS results require a diagnostic sweat test at a CF center. Results that were "screen positive and diagnosis negative" prompted family genetic counseling. Parent compliance with follow-up protocol recommendations was retrospectively analyzed relative to the communications model in place at a particular CF Center. At each of the 5 MA CF centers, 95% of the CF NBS-positive infants completed recommended sweat testing. In contrast, there was wide disparity in compliance (32%-90%) with completion of genetic counseling between CF centers. CF centers that escorted parents through the 2 recommended follow-up steps in 1 day had higher compliance with the second step (genetic counseling) than centers that required a return visit for genetic counseling.

Diagnostic dilemmas resulting from the immunoreactive trypsinogen/DNA cystic fibrosis newborn screening algorithm

To quantitate the proportion of infants identified through cystic fibrosis (CF) newborn screening (NBS) by an immunoreactive trypsinogen (IRT)/DNA screening algorithm who have an unclear diagnosis as defined by the findings of an elevated IRT level and either 1) 2 CF gene (CFTR) mutations detected and sweat chloride level <60 mEq/L; or 2) 0 or 1 CFTR mutations and a "borderline" sweat chloride level >or=30 and <60 mEq/L. Using the 4-year cohort of CF-affected infants recently described by the Massachusetts CF NBS program, we identified and described the number of infants with the diagnostic characteristics (diagnostic dilemmas) aforementioned. Of infants with positive results on CF NBS who had 1 CFTR mutation detected and a borderline sweat chloride concentration, nearly 20% displayed a second CFTR mutation on further evaluation. Of all infants with positive CF NBS results considered affected with CF, 11% had a diagnosis that fell into 1 of the diagnostic dilemma categories aforementioned. Four problematic diagnostic categories generated by CF NBS are defined. In the absence of data on the natural history of such infants, careful follow-up is recommended for infants in whom a definitive diagnosis is elusive.

ANTIDEPRESSANT DRUGS AND LIVER DAMAGE.

<h3>Objective</h3> To explore primary care providers’ (PCPs’) role in result notification for newborn screening (NBS) for cystic fibrosis (CF), given that expanded NBS has increased the number of positive screening test results, drawing attention to the role of PCPs in supporting families. <h3>Design</h3> Cross-sectional survey and qualitative interviews. <h3>Setting</h3> Ontario. <h3>Participants</h3> Primary care providers (FPs, pediatricians, and midwives) who received a positive CF NBS result for an infant in their practice in the 6 months before the study. <h3>Main outcome measures</h3> Whether the PCP notified the family of the initial positive CF screening result. <h3>Results</h3> Data from 321 PCP surveys (response rate of 51%) are reported, including 208 FPs, 68 pediatricians, and 45 midwives. Interviews were completed with 34 PCPs. Most (65%) surveyed PCPs reported notifying the infant’s family of the initial positive screening result; 81% agreed that they have an important role to play in NBS; and 88% said it was important for PCPs, rather than the NBS centre, to notify families of initial positive results. With support and information from NBS centres, 68% would be extremely or very confident in doing so; this dropped to 54% when reflecting on their recent reporting experience. More than half (58%) of all PCPs said written point-of-care information from the NBS centre was the most helpful format. Adjusted for relevant factors, written educational information was associated with a lower rate of notifying families than written plus verbal information (risk ratio of 0.79; 95% CI 0.69 to 0.92). In the interviews, PCPs emphasized the challenge of balancing required content knowledge with the desire for the news to come from a familiar provider. <h3>Conclusion</h3> Most PCPs notify families of NBS results and value this role. These data are relevant as NBS programs and other genomic services expand and consider ways of keeping PCPs confident and actively involved.