Cystic Fibrosis Foundation Evidence-Based Guideline for the Management of CRMS/CFSPID.

A multidisciplinary committee developed evidence-based guidelines for the management of cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen-positive, inconclusive diagnosis (CRMS/CFSPID). A total of 24 patient, intervention, comparison, and outcome questions were generated based on surveys sent to people with CRMS/CFSPID and clinicians caring for these individuals, previous recommendations, and expert committee input. Four a priori working groups (genetic testing, monitoring, treatment, and psychosocial/communication issues) were used to provide structure to the committee. A systematic review of the evidence was conducted, and found numerous case series and cohort studies, but no randomized clinical trials. A total of 30 recommendations were graded using the US Preventive Services Task Force methodology. Recommendations that received ≥80% consensus among the entire committee were approved. The resulting recommendations were of moderate to low certainty for the majority of the statements because of the low quality of the evidence. Highlights of the recommendations include thorough evaluation with genetic sequencing, deletion/duplication analysis if <2 disease-causing variants were noted in newborn screening; repeat sweat testing until at least age 8 but limiting further laboratory testing, including microbiology, radiology, and pulmonary function testing; minimal use of medications, which when suggested, should lead to shared decision-making with families; and providing communication with emphasis on social determinants of health and shared decision-making to minimize barriers which may affect processing and understanding of this complex designation. Future research will be needed regarding medication use, antibiotic therapy, and the use of chest imaging for monitoring the development of lung disease.

Missed Cystic Fibrosis Newborn Screening Cases due to Immunoreactive Trypsinogen Levels below Program Cutoffs: A National Survey of Risk Factors.

Testing immunoreactive trypsinogen (IRT) is the first step in cystic fibrosis (CF) newborn screening. While high IRT is associated with CF, some cases are missed. This survey aimed to find factors associated with missed CF cases due to IRT levels below program cutoffs. Twenty-nine states responded to a U.S-wide survey and 13 supplied program-related data for low IRT false screen negative cases (CFFN) and CF true screen positive cases (CFTP) for analysis. Rates of missed CF cases and odds ratios were derived for each factor in CFFNs, and two CFFN subgroups, IRT above ("high") and below ("low") the CFFN median (39 ng/mL) compared to CFTPs for this entire sample set. Factors associated with "high" CFFN subgroup were Black race, higher IRT cutoff, fixed IRT cutoff, genotypes without two known CF-causing variants, and meconium ileus. Factors associated with "low" CFFN subgroup were older age at specimen collection, Saturday birth, hotter season of newborn dried blood spot collection, maximum ≥ 3 days laboratories could be closed, preterm birth, and formula feeding newborns. Lowering IRT cutoffs may reduce "high" IRT CFFNs. Addressing hospital and laboratory factors (like training staff in collection of blood spots, using insulated containers during transport and reducing consecutive days screening laboratories are closed) may reduce "low" IRT CFFNs.

Trends in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Seroprevalence in Massachusetts Estimated from Newborn Screening Specimens.

BACKGROUND: Estimating the cumulative incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for setting public health policies. We leveraged deidentified Massachusetts newborn screening specimens as an accessible, retrospective source of maternal antibodies for estimating statewide seroprevalence in a nontest-seeking population. METHODS: We analyzed 72 117 newborn specimens collected from November 2019 through December 2020, representing 337 towns and cities across Massachusetts. Seroprevalence was estimated for the Massachusetts population after correcting for imperfect test specificity and nonrepresentative sampling using Bayesian multilevel regression and poststratification. RESULTS: Statewide seroprevalence was estimated to be 0.03% (90% credible interval [CI], 0.00-0.11) in November 2019 and rose to 1.47% (90% CI: 1.00-2.13) by May 2020, following sustained SARS-CoV-2 transmission in the spring. Seroprevalence plateaued from May onward, reaching 2.15% (90% CI: 1.56-2.98) in December 2020. Seroprevalence varied substantially by community and was particularly associated with community percent non-Hispanic Black (ß = .024; 90% CI: 0.004-0.044); i.e., a 10% increase in community percent non-Hispanic Black was associated with 27% higher odds of seropositivity. Seroprevalence estimates had good concordance with reported case counts and wastewater surveillance for most of 2020, prior to the resurgence of transmission in winter. CONCLUSIONS: Cumulative incidence of SARS-CoV-2 protective antibody in Massachusetts was low as of December 2020, indicating that a substantial fraction of the population was still susceptible. Maternal seroprevalence data from newborn screening can inform longitudinal trends and identify cities and towns at highest risk, particularly in settings where widespread diagnostic testing is unavailable.

Novel Modification of a Confirmatory SMA Sequencing Assay that Can Be Used to Determine SMN2 Copy Number.

Promising treatments for spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, prompted calls for inclusion in newborn screening (NBS). In January 2018, the New England Newborn Screening Program (NENSP) began statewide screening for SMA using a tiered algorithm looking for the absence of SMN1 Exon 7. When results from the first and second tier needed reconciliation, we developed and validated a third tier DNA sequencing assay to ensure the presence or absence of SMN1 Exon 7. All nine infants referred to specialty centers through NBS showed single base substitution of c.840C>T, and were confirmed to have SMA. Further, a minor sequencing protocol modification allowed the estimation of SMN2 copy number in SMA affected patients; we developed and validated a copy-number assay yielding 100% match with seven previously characterized specimens of SMA patients. All nine SMA-affected infants found through NBS were also assayed for SMN2 copy number. Results were comparable but not 100% matched with those that were reported by independent diagnostic laboratories. In conclusion, a sequencing protocol confirms NBS findings from real-time qPCR, and its modified application allows NBS programs that have sequencing capabilities to provide SMN2 copy numbers without the need for additional instrumentation.

Massachusetts' Findings from Statewide Newborn Screening for Spinal Muscular Atrophy.

Massachusetts began newborn screening (NBS) for Spinal Muscular Atrophy (SMA) following the availability of new treatment options. The New England Newborn Screening Program developed, validated, and implemented a screening algorithm for the detection of SMA-affected infants who show absent SMN1 Exon 7 by Real-Time™ quantitative PCR (qPCR). We screened 179,467 neonates and identified 9 SMA-affected infants, all of whom were referred to a specialist by day of life 6 (average and median 4 days of life). Another ten SMN1 hybrids were observed but never referred. The nine referred infants who were confirmed to have SMA were entered into treatment protocols. Early data show that some SMA-affected children have remained asymptomatic and are meeting developmental milestones and some have mild to moderate delays. The Massachusetts experience demonstrates that SMA NBS is feasible, can be implemented on a population basis, and helps engage infants for early treatment to maximize benefit.

Ten Years of Newborn Screening for Severe Combined Immunodeficiency (SCID) in Massachusetts.

BACKGROUND: Massachusetts began newborn screening (NBS) for severe combined immunodeficiency (SCID) using measurement of T-cell receptor excision circles (TRECs) from dried blood spots. OBJECTIVE: We describe developments and outcomes from the first 10 years of this program (February 1, 2009, to January 31, 2019). METHODS: TREC values, diagnostic, and outcome data from all patients screened for SCID were evaluated. RESULTS: NBS of 720,038 infants prompted immunologic evaluation of 237 (0.03%). Of 237, 9 were diagnosed with SCID/leaky SCID (4% of referrals vs 0.001% general population). Another 7 were diagnosed with other combined immunodeficiencies, and 3 with athymia. SCID/leaky SCID incidence was approximately 1 in 80,000, whereas approximately 1 in 51,000 had severe T-cell lymphopenia for which definitive treatment was indicated. All patients with SCID/leaky SCID underwent hematopoietic cell transplant or gene therapy with 100% survival. One patient with athymia underwent successful thymus transplant. No known cases of SCID were missed. Compared with outcomes from the 10 years before SCID NBS, survival trended higher (9 of 9 vs 4 of 7), likely due to a lower rate of infection before treatment. CONCLUSIONS: Our data support a single NBS testing-and-referral algorithm for all gestational ages. Despite lower median TREC values in premature infants, the majority for all ages are well above the TREC cutoff and the algorithm, which selects urgent (undetectable TREC) and repeatedly abnormal TREC values, minimizes referral. We also found that low naïve T-cell percentage is associated with a higher risk of SCID/CID, demonstrating the utility of memory/naïve T-cell phenotyping as part of follow-up flow cytometry.

Two Unique Cases of X-linked SCID: A Diagnostic Challenge in the Era of Newborn Screening.

In the era of newborn screening (NBS) for severe combined immunodeficiency (SCID) and the possibility of gene therapy (GT), it is important to link SCID phenotype to the underlying genetic disease. In western countries, X-linked interleukin 2 receptor gamma chain (IL2RG) and adenosine deaminase (ADA) deficiency SCID are two of the most common types of SCID and can be treated by GT. As a challenge, both IL2RG and ADA genes are highly polymorphic and a gene-based diagnosis may be difficult if the variant is of unknown significance or if it is located in non-coding areas of the genes that are not routinely evaluated with exon-based genetic testing (e.g., introns, promoters, and the 5'and 3' untranslated regions). Therefore, it is important to extend evaluation to non-coding areas of a SCID gene if the exon-based sequencing is inconclusive and there is strong suspicion that a variant in that gene is the cause for disease. Functional studies are often required in these cases to confirm a pathogenic variant. We present here two unique examples of X-linked SCID with variable immune phenotypes, where IL2R gamma chain expression was detected and no pathogenic variant was identified on initial genetic testing. Pathogenic IL2RG variants were subsequently confirmed by functional assay of gamma chain signaling and maternal X-inactivation studies. We propose that such tests can facilitate confirmation of suspected cases of X-linked SCID in newborns when initial genetic testing is inconclusive. Early identification of pathogenic IL2RG variants is especially important to ensure eligibility for gene therapy.

Newborn screening for severe combined immunodeficiency in 11 screening programs in the United States.

IMPORTANCE: Newborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births. OBJECTIVES: To present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments. DESIGN: Epidemiological and retrospective observational study. SETTING: Representatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test. MAIN OUTCOMES AND MEASURES: Infants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked. RESULTS: Screening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia. CONCLUSIONS AND RELEVANCE: Newborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined.

Long-term follow-up to ensure quality care of individuals diagnosed with newborn screening conditions: early experience in New England.

To fulfill the purpose of newborn screening, comprehensive newborn screening programs must ensure that infants and children with newborn screening conditions are not only diagnosed but also they maintain engagement in appropriate lifespan and family-centered care for best outcomes. To ensure success, monitoring and care-coordination requires a systems-based approach to streamline the significant surveillance activities, which must not overburden the critical core functions of newborn screening nor the health care delivery system. Furthermore, treatment and care can only be improved by translating reliable knowledge into changes in practice, a process that requires evaluations of outcomes that are confirmable at the local level and translatable into a larger, e.g., national data set. We describe a sustainable public health systems approach to long-term follow-up, built on existing comprehensive newborn screening infrastructure and compatible with national endeavors. We also describe early experience with implementation of a centralized public-health tracking model and show that a significant proportion of cases detected through newborn screening do not continue with subspecialty care as they get older.

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.

Guidelines for implementation of population-based newborn screening for severe combined immunodeficiency.

Severe combined immunodeficiency (SCID) is a Primary Immune Deficiency that is under consideration for population-based newborn screening (NBS) by many NBS programs, and has recently been recommended for inclusion in the US uniform panel of newborn screening conditions. A marker of SCID, the T cell receptor excision circle (TREC), is detectable in the newborn dried blood spot using a unique molecular assay as a primary screen. The New England Newborn Screening Program developed and validated a multiplex TREC assay in which both the TREC analyte and an internal control are acquired from a single punch and run in the same reaction. Massachusetts then implemented a statewide pilot SCID NBS program. The authors describe the rationale for a pilot SCID NBS program, a comprehensive strategy for successful implementation, the screening test algorithm, the screening follow-up algorithm and preliminary experience based on statewide screening in the first year. The Massachusetts experience demonstrates that SCID NBS is a program that can be implemented on a population basis with reasonable rates of false positives.