Can incorporating molecular testing improve the accuracy of newborn screening for congenital adrenal hyperplasia?

BACKGROUND

Single-tier newborn screening (NBS) for CAH using 17-hydroxyprogesterone (17OHP) measured by fluoroimmunoassay (FIA) in samples collected at 24-48 hours produces a high false-positive rate (FPR). 2nd tier steroid testing can reduce the FPR and has been widely implemented. We investigated the accuracy of an alternative multi-tier CAH NBS protocol that incorporates molecular testing of the CYP21A2 gene and reduces the 1st tier 17OHP cutoff to minimize missed cases.

METHODS

Created a Minnesota-specific CYP21A2 pathogenic variants panel; develop a rapid, high-throughput multiplex, allele-specific-primer-extension assay; perform 1-year retrospective analysis of Minnesota NBS results comparing metrics between a conventional steroid-based two-tier protocol and a molecular-based multi-tier NBS protocol, applied post-hoc.

RESULTS

CYP21A2 gene sequencing of 103 Minnesota families resulted in a Minnesota-specific panel of 21 pathogenic variants. Centers for Disease Control and Prevention (CDC) created a molecular assay with 100% accuracy and reproducibility. Two-tier steroid-based screening of 68,659 live births during 2015 resulted in 2 false negatives (FNs), 91 FPs, and 1 true positive (TP). A three-tier protocol with a lower 1st-tier steroid cutoff, 2nd-tier 21-variant CYP21A2 panel and 3rd-tier CYP21A2 sequencing would have resulted in 0 FNs, 52 FPs and 3 TPs.

CONCLUSIONS

Incorporation of molecular testing could improve the accuracy of CAH NBS, although some distinct challenges of molecular testing may need to be considered before implementation by NBS programs.

Consensus guidelines for the monitoring and management of metachromatic leukodystrophy in the United States

Metachromatic leukodystrophy (MLD) is a fatal, progressive neurodegenerative disorder caused by biallelic pathogenic mutations in the ARSA (Arylsulfatase A) gene. With the advent of presymptomatic diagnosis and the availability of therapies with a narrow window for intervention, it is critical to define a standardized approach to diagnosis, presymptomatic monitoring, and clinical care. To meet the needs of the MLD community, a panel of MLD experts was established to develop disease-specific guidelines based on healthcare resources in the United States. This group developed a consensus opinion for best-practice recommendations, as follows: (i) Diagnosis should include both genetic and biochemical testing; (ii) Early diagnosis and treatment for MLD is associated with improved clinical outcomes; (iii) The panel supported the development of newborn screening to accelerate the time to diagnosis and treatment; (iv) Clinical management of MLD should include specialists familiar with the disease who are able to follow patients longitudinally; (v) In early onset MLD, including late infantile and early juvenile subtypes, ex vivo gene therapy should be considered for presymptomatic patients where available; (vi) In late-onset MLD, including late juvenile and adult subtypes, hematopoietic cell transplant (HCT) should be considered for patients with no or minimal disease involvement. This document summarizes current guidance on the presymptomatic monitoring of children affected by MLD as well as the clinical management of symptomatic patients. Future data-driven evidence and evolution of these recommendations will be important to stratify clinical treatment options and improve clinical care.

Newborn Screening for Severe Combined Immunodeficiency: Lessons Learned from Screening and Follow-Up of the Preterm Newborn Population

Newborn screening (NBS) for Severe Combined Immunodeficiency (SCID) by measurement of T-cell receptor excision circles (TRECs) successfully identifies newborns with SCID and severe T-cell lymphopenia, as intended. At the same time, NBS programs face the challenge of false positive results, with a disproportionately high number in the premature newborn population. This study evaluates TREC values and SCID screening outcomes in premature newborns and elucidates evidence-based SCID screening practices that reduce unnecessary follow-up activities in this population. De-identified individual SCID newborn screening data and aggregate SCID screening data were obtained from seven states across the US for babies born between 2018 and 2020. Relevant statistics were performed on data pooled from these states to quantify screening performance metrics and clinical impact on various birth and gestational age categories of newborns. The data were normalized using multiples-of-the-median (MoM) values to allow for the aggregation of data across states. The aggregation of NBS data across a range of NBS programs highlighted the trajectory of TREC values over time, both between and within newborns, and provides evidence for improved SCID screening recommendations in the premature and low birth weight population.

Infants with Congenital Diseases Identified through Newborn Screening-United States, 2018-2020

Newborn screening (NBS) is a state or territory-based public health system that screens newborns for congenital diseases that typically do not present with clinical symptoms at birth but can cause significant mortality and morbidity if not detected or treated quickly. NBS continues to be one of the most successful public health interventions in the US, providing early detection and intervention to all infants. The increase in overall birth prevalence of core Recommended Uniform Screening Panel (RUSP) diseases detected via dried blood spot (DBS) specimens from 2015-2017 (17.50-18.31 per 10,000) to 2018-2020 (20.07 per 10,000), as reported into the APHL NewSTEPs database, affirms the importance and impact of NBS programs. This report presents aggregate numbers and birth prevalence of diseases detected by DBS on the RUSP from 2018-2020, including data from fifty US states and two territories.

Population-Based Screening of Newborns: Findings From the NBS Expansion Study (Part One)

Each year, through population-based newborn screening (NBS), 1 in 294 newborns is identified with a condition leading to early treatment and, in some cases, life-saving interventions. Rapid advancements in genomic technologies to screen, diagnose, and treat newborns promise to significantly expand the number of diseases and individuals impacted by NBS. However, expansion of NBS occurs slowly in the United States (US) and almost always occurs condition by condition and state by state with the goal of screening for all conditions on a federally recommended uniform panel. The Newborn Screening Translational Research Network (NBSTRN) conducted the NBS Expansion Study to describe current practices, identify expansion challenges, outline areas for improvement in NBS, and suggest how models could be used to evaluate changes and improvements. The NBS Expansion Study included a workshop of experts, a survey of clinicians, an analysis of data from online repositories of state NBS programs, reports and publications of completed pilots, federal committee reports, and proceedings, and the development of models to address the study findings. This manuscript (Part One) reports on the design, execution, and results of the NBS Expansion Study. The Study found that the capacity to expand NBS is variable across the US and that nationwide adoption of a new condition averages 9.5 years. Four factors that delay and/or complicate NBS expansion were identified. A companion paper (Part Two) presents a use case for each of the four factors and highlights how modeling could address these challenges to NBS expansion.

Newborn Screening for Cystic Fibrosis: A Qualitative Study of Successes and Challenges from Universal Screening in the United States

Cystic fibrosis (CF) newborn screening (NBS) was universally adopted in 2009 in the United States. Variations in NBS practices between states may impact the timing of diagnosis and intervention. Quantitative metrics can provide insight into NBS programs (NBSP), but the nuances cannot be elucidated without additional feedback from programs. This study was designed to determine facilitators and barriers to timely diagnosis and intervention following NBS for CF. The median age at the first CF event for infants with CF within each state was used to define early and late states (n = 15 per group); multiple CF centers were invited in states with more than two CF centers. Thirty states were eligible, and 61 NBSP and CF centers were invited to participate in structured interviews to determine facilitators and barriers. Once saturation of themes was reached, no other interviews were conducted. Forty-five interviews were conducted (n = 16 early CF center, n = 12 late CF center, n = 11 early NBSP, and n = 6 late NBSP). Most interviewees reported good communication between CF centers and NBSP. Communication between primary care providers (PCPs) and families was identified as a challenge, leading to delays in referral and subsequent diagnosis. The misperception of low clinical risk in infants from racial and ethnic minority groups was a barrier to early diagnostic evaluation for all groups. NBSP and CF centers have strong relationships. Early diagnosis may be facilitated through more engagement with PCPs. Quality improvement initiatives should focus on continuing strong partnerships between CF centers and NBS programs, improving education, communication strategies, and partnerships with PCPs, and improving CF NBS timeliness and accuracy.

Newborn screening for neurodevelopmental diseases: Are we there yet?

In the US, newborn screening (NBS) is a unique health program that supports health equity and screens virtually every baby after birth, and has brought timely treatments to babies since the 1960's. With the decreasing cost of sequencing and the improving methods to interpret genetic data, there is an opportunity to add DNA sequencing as a screening method to facilitate the identification of babies with treatable conditions that cannot be identified in any other scalable way, including highly penetrant genetic neurodevelopmental disorders (NDD). However, the lack of effective dietary or drug-based treatments has made it nearly impossible to consider NDDs in the current NBS framework, yet it is anticipated that any treatment will be maximally effective if started early. Hence there is a critical need for large scale pilot studies to assess if and how NDDs can be effectively screened at birth, if parents desire that information, and what impact early diagnosis may have. Here we attempt to provide an overview of the recent advances in NDD treatments, explore the possible framework of setting up a pilot study to genetically screen for NDDs, highlight key technical, practical, and ethical considerations and challenges, and examine the policy and health system implications.

COVID-19 Pandemic-Related Impacts on Newborn Screening Public Health Surveillance

Newborn screening (NBS) is an essential public health service that performs screening to identify those newborns at increased risk for a panel of disorders, most of which are genetic. The goal of screening is to link those newborns at the highest risk to timely intervention and potentially life-saving treatment. The global COVID-19 pandemic led to disruptions within the United States public health system, revealing implications for the continuity of newborn screening laboratories and follow-up operations. The impacts of COVID-19 across different states at various time points meant that NBS programs impacted by the pandemic later could benefit from the immediate experiences of the earlier impacted programs. This article will review the collection, analysis, and dissemination of information during the COVID-19 pandemic facilitated by a national, centralized technical assistance and resource center for NBS programs.

Development of an Implementation Framework for Overcoming Underdiagnoses of Familial Hypercholesterolemia in the USA

Familial hypercholesterolemia (FH) is a genetic condition which causes elevated low-density lipoprotein cholesterol from birth. With a prevalence of 1 in 250 and the availability of effective treatments, the diagnostic rate of <1 to 10% is unacceptably low. Screening for FH is supported by multiple organizations, but it has not been broadly adopted and implemented across the USA. To investigate the implementation of FH screening, key informants were recruited from across the USA for their expertise in FH-related literature, guidelines, public health, and/or advocacy to complete -semistructured interviews guided by implementation science (RE-AIM framework). Sixteen semistructured interviews were analyzed with directed content and thematic analyses, yielding specific barriers and recommendations to improve FH screening. Barriers to FH screening included patient recruitment and participation, equitable access to healthcare, provider discomfort with screening and treating FH, provider burden, lack of public health and legislative support, FH awareness, guideline complexity, facilitation of genetic testing and cascade screening, and lack of coordination between stakeholders. Awareness, engagement, communication, and collaboration between stakeholders is integral to successful FH screening. Individualized plans will be required at national, regional, and institutional levels. FH screening implementation can be achieved through practice facilitation, streamlined screening approaches, electric medical record tools, and consensus guidelines to increase screening adoption and consistent delivery. Reliable funding and established lines of communication between stakeholders can maintain efforts as FH screening progresses.

Updated Strategies for Pulse Oximetry Screening for Critical Congenital Heart Disease

Seven years after its addition to the US Recommended Uniform Screening Panel, newborn screening for critical congenital heart disease (CCHD) using pulse oximetry became mandatory in the United States. Although CCHD newborn screening reduces morbidity and mortality, there remain important opportunities to improve. An expert panel convened for a 1-day meeting in September 2018, including subject matter experts and representatives from stakeholder organizations. Presentations on CCHD outcomes, variations in approach to screening, and data and quality improvement helped identify improvement opportunities. The expert panel concluded that sufficient evidence exists to recommend modifying the current American Academy of Pediatrics algorithm by (1) requiring an oxygen saturation of at least 95% in both (formerly either) the upper and lower extremities to pass and (2) requiring only 1 repeat screen instead of 2 for cases that neither pass nor fail initially. The panel underscored the importance of improving public health reporting by further specifying the targets of screening and criteria for reporting outcomes (false-negative and false-positive cases). The panel also highlighted the need to ensure sufficient public health funding for CCHD newborn screening and opportunities for education and global implementation. Newborn screening for CCHD using pulse oximetry has led to significant improvements in child health outcomes. However, further important work is required to understand and improve the effectiveness and efficiency of screening.

A Newborn Screening Education Best Practices Framework: Development and Adoption

Newborn screening is a process-based public health service. Newborn screening staff and families alike are essential to maintaining the timeliness of the screening process. Newborn screening education must be accurate and accessible. Past newborn screening conferences have highlighted gaps in best practice and evidence-based guidance on newborn screening education. Sharing successful strategies across programs mitigates the scarcity of resources by cutting costs and reducing the burden of work. These factors illustrate the need for an education framework to guide newborn screening education efforts. The Newborn Screening Education Best Practices Framework responds to these issues by outlining guidance for newborn screening education approaches. Experts in the fields of newborn screening, genetics, and bioethics as well as previous research on best practice guidelines have contributed to the development of this framework. The framework outlines a process for users to evaluate newborn screening education approaches as best practices. This framework reviews best practices using a two-step approach, looking at guiding questions, implementation of the newborn screening issue, and evaluation. The framework helps the user define the characteristics of the newborn screening issue, intended audience, and practical steps to implementation, and then decide whether or not it can be used as a best practice.

A report on state-wide implementation of newborn screening for X-linked Adrenoleukodystrophy

Minnesota became the fourth state to begin newborn screening (NBS) for X‐linked adrenoleukodystrophy (X‐ALD) in 2017. As there is limited retrospective data available on NBS for X‐ALD, we analyzed Minnesota's NBS results from the first year of screening. C26:0 lysophosphatidylcholine (C26:0‐LPC) screening results of 67,836 infants and confirmatory testing (ABCD1 gene and serum VLCFA analysis) for screen positives were obtained. Fourteen infants (nine males, five females) screened positive for X‐ALD and all were subsequently confirmed to have X‐ALD, with zero false positives. The birth prevalence of X‐ALD in screened infants was 1 in 4,845 and 1 in 3,878 males, more than five times previous reported incidences. Pedigrees of affected infants were analyzed, and 17 male (mean age of 17) and 24 female relatives were subsequently diagnosed with X‐ALD. Phenotypes of these family members included self‐reported mild neuropathy symptoms in two males and seven females, and childhood cerebral disease (ccALD) and adrenal insufficiency in one male. We observed fewer cases of ccALD and adrenal insufficiency than expected in male family members (5.9% of males for both) compared to previous observations. Together, these findings suggest that the spectrum of X‐ALD may be broader than previously described and that milder cases may previously have been underrepresented. Other challenges included a high frequency of variants of uncertain significance in ABCD1 and an inability to predict phenotypic severity. We posit that thoughtful planning to address these novel challenges and coordination by dedicated specialists will be imperative for successful implementation of population‐based screening for X‐ALD.

Introduction to the Special Issue: Public Health Genetics and Genomics

This special issue of the Journal of Genetic Counseling is dedicated to public health genetics and genomics. The seventeen papers featured in this issue span such topics as genetic counselors in public health roles, newborn screening, population screening, ethics, and health beliefs and behaviors. In this introduction to the special issue, we review some history of public health genetics and genomics, present the Centers for Disease Control and Prevention's "10 Essential Public Health Services" with associated genetics specific recommendations and priorities, and briefly overview how each article ties into the world of public health genetics and genomics. We hope this issue encourages genetic counselors to visualize their ever expanding and important roles in public health genetics and genomics, as well as their contributions to improving population health.

A comparison of retesting rates using alternative testing algorithms in the pilot implementation of critical congenital heart disease screening in Minnesota

Prior to state-wide implementation of newborn screening for critical congenital heart disease (CCHD) in Minnesota, a pilot program was completed using the protocol recommended by the Secretary's Advisory Committee on Heritable Disorders in Newborns and Children (SACHDNC). This report compares the retesting rates for newborn screening for CCHDs using the SACHDNC protocol and four alternative algorithms used in large published CCHD screening studies. Data from the original Minnesota study were reanalyzed using the passing values from these four alternative protocols. The retesting rate for the first pulse oximeter measurement ranged from 1.1 % in the SACHDNC protocol to 9.6 % in the Ewer protocol. The SACHDNC protocol generated the lowest rate of retesting among all tested algorithms. Our data suggest that even minor modifications of CCHD screening protocol would significantly impact screening retesting rate. In addition, we provide support for including lower extremity oxygen saturations in the screening algorithm.

Comparison of newborn screening protocols for congenital adrenal hyperplasia in preterm infants

OBJECTIVE

To compare 2 screening protocols performed concurrently in Minnesota: (1) liquid chromatography tandem mass spectrometry steroid profiling as a second-tier test on positive fluoroimmunoassay (FIA) results; and (2) low-birthweight 3-screen protocol (FIA tests at <48 hours, 2 weeks, 4 weeks) on all infants <1800 g, regardless of result.

STUDY DESIGN

Population-based study of all <1800 g infants (n = 8739) born in Minnesota from 2004-2010 comparing newborn screening performance metrics of 2-tier (FIA + liquid chromatography tandem mass spectrometry) protocol (2004-2010) vs 1-tier (FIA) low-birthweight 3-screen protocol (2006-2010). False positive (FP) rates were calculated per infant's final confirmatory result. Protocol results used in different time periods (2004-2005 vs 2006-2010) were compared by 2-sample tests of proportions; results of both protocols for 2006-2010 were compared by McNemar test.

RESULTS

First-tier testing of final dried blood spot result (n = 6625) of the low-birthweight 3-screen protocol during 2006-2010 reduced the FP rate more than 5-fold (P < .0001) compared with 2-tier testing of a single dried blood spot (n = 2114) from 2004-2005. In comparing results (n = 6625) of both protocols from 2006-2010, first-tier testing of final dried blood spot accounted for 23% of FPs; second-tier testing of the first dried blood spot accounted for 77%, yielding significantly more FP results (McNemar test, P < .0001).

CONCLUSION

Timing of dried blood spot collection rather than assay used played a more important role in reducing FP results of congenital adrenal hyperplasia newborn screening in low birthweight infants.

Implementation of critical congenital heart disease screening in Minnesota

OBJECTIVE

To assess the level of preparedness and resources needed in Minnesota for the implementation of newborn screening for critical congenital heart diseases (CCHDs).

METHODS

A cross sectional survey of all birth centers in Minnesota was performed to assess the capacity to deliver care essential for the CCHD screening program. Compliance with the screening algorithm, nursing workload, and cost were assessed by using a pilot program implemented in 6 normal newborn nurseries.

RESULTS

Ninety-one of 99 eligible centers participated in the survey and 90 reported the ability to screen newborns in accordance with recommendations. Only 22 centers, with 63% of births, had access to echocardiography and routinely stocked prostaglandins for neonatal use. Our pilot study screened 7549 newborns with 6 failed screens and 1 CCHD diagnosis. Two of the failed screens were due to misinterpretation of the algorithm, 1 failed screen was not reported, and 4 failed screens were not recognized. Repeated screens were required for 115 newborns, with 29% of retesting due to misinterpretation of the algorithm. The mean nursing time required was 5.5 minutes, and the cost was $5.10 per screen.

CONCLUSIONS

In Minnesota, two-thirds of newborns are born in centers with resources for initial diagnosis and management of CCHD. Implementation of a pilot screening program demonstrated minimal increase in nursing workload, but identified problems with interpretation of the algorithm and data reporting. This pilot project suggests the need for simplification of the algorithm, additional training of health care providers, and development of a centralized reporting mechanism.

Newborn screening: education, consent, and the residual blood spot. The position of the national society of genetic counselors

Newborn screening (NBS) is a minimally invasive lifesaving test. There is currently no federal mandate for NBS, thus states determine their own screening panel based on the recommendations of the Secretary's Advisory Committee on Heritable Disorders in Newborn and Children (SACHDNC), which was recently re-chartered as the Discretionary Advisory Committee on Heritable Disorders in Newborns and Children (DACHDNC). After NBS is completed, a couple of residual blood spots remain. While some states allow these spots to be used for public health and scientific research purposes, parents are not always informed about these additional uses. This paper addresses the National Society of Genetic Counselors' (NSGC's) position about NBS and blood spot storage/use and the rationale for these positions. The National Society of Genetic Counselors strongly supports newborn screening for the uniform screening panel of conditions recommended by the Secretary's Advisory Committee on Heritable Disorders in Newborns and Children. NSGC also supports storage and use of blood spot samples by newborn screening laboratories and transparent policies that govern these activities.

Comparison of one-tier and two-tier newborn screening metrics for congenital adrenal hyperplasia

BACKGROUND

Newborn screening (NBS) for the classic forms of congenital adrenal hyperplasia (CAH) is mandated in all states in the United States. Compared with other NBS disorders, the false-positive rate (FPR) of CAH screening remains high and has not been significantly improved by adjusting 17α-hydroxyprogesterone cutoff values for birth weight and/or gestational age. Minnesota was the first state to initiate, and only 1 of 4 states currently performing, second-tier steroid profiling for CAH. False-negative rates (FNRs) for CAH are not well known.

METHODS

This is a population-based study of all Minnesota infants (769,834) born 1999-2009, grouped by screening protocol (one-tier with repeat screen, January 1999 to May 2004; two-tier with second-tier steroid profiling, June 2004 to December 2009). FPR, FNR, and positive predictive value (PPV) were calculated per infant, rather than per sample, and compared between protocols.

RESULTS

Overall, 15 false-negatives (4 salt-wasting, 11 simple-virilizing) and 45 true-positives were identified from 1999 to 2009. With two-tier screening, FNR was 32%, FPR increased to 0.065%, and PPV decreased to 8%, but these changes were not statistically significant. Second-tier steroid profiling obviated repeat screens of borderline results (355 per year average).

CONCLUSIONS

In comparing the 2 screening protocols, the FPR of CAH NBS remains high, the PPV remains low, and false-negatives occur more frequently than has been reported. Physicians should be cautioned that a negative NBS does not necessarily rule out classic CAH; therefore, any patient for whom there is clinical concern for CAH should receive immediate diagnostic testing.

Siblings with mitochondrial acetoacetyl-CoA thiolase deficiency not identified by newborn screening

Screened for by all state newborn screening (NBS) programs in the United States, mitochondrial acetoacetyl-coenzyme A thiolase (T2), or β-ketothiolase, deficiency is a rare autosomal recessive disorder that causes ketoacidosis and hypoglycemia/hyperglycemia. Outcomes vary from normal development to severe cognitive impairment or even death after an acute episode of ketoacidosis. The classical biochemical profile of T2 deficiency is a result of null mutations in both alleles of the ACAT1 gene and consists of persistently increased urinary excretion of ketones, characteristic organic acids, and tiglylglycine as well as abnormal blood or plasma acylcarnitine profiles in acute and stable conditions. Early diagnosis and aggressive management can prevent further episodes of ketoacidosis and lead to normal development. We report the cases of 3 children, all subsequently found to have mutations predicted to be associated with no residual T2 enzymatic activity, but only 1 was identified by NBS in Minnesota since 2001. To our knowledge, this is the first description of compound heterozygotes for null mutations associated with no enzymatic activity exhibiting normal urinary organic acid, blood, and plasma acylcarnitine profiles when clinically well, thereby explaining the false-negative NBS results. We suggest that T2 deficiency may be underrecognized, because the incidence of T2 deficiency in Minnesota, on the basis of these 3 cases, is 1 in 232 000, higher than the reported <1 in 1 million incidence. Our cases emphasize that T2 deficiency must be considered in patients who present with ketoacidosis disproportionately severe to the triggering illness despite normal NBS results or nonspecific biochemical findings in blood and urine during asymptomatic periods.

High incidence of profound biotinidase deficiency detected in newborn screening blood spots in the Somalian population in Minnesota

Newborns identified with profound biotinidase deficiency (BTD) by the Minnesota Newborn Screening Program (MN NBS) between 1 October 2004 and 30 May 2008 were all from new immigrant groups. Thirty-three positive cases of BTD were identified out of 264 727 infants screened by the Wolf colorimetric system during the period of this study by MN NBS. Five cases of profound BTD (0.1 to <0.6 nmol/min per ml) and 26 cases of partial BTD (0.9 to 2.3 nmol/min per ml) were later confirmed through measurement of serum biotinidase activity. The incidence of combined partial and profound BTD of 1/8540 and that of profound BTD of 1/52 945 in Minnesota are unusually high in comparison with the reported worldwide numbers of 1/61 067 for combined BTD and 1/137 401 for profound BTD. Four out of the 5 cases of profound BTD ascertained in the MN NBS cohort were of Somali ethnic background, and the remaining case was of Asian (Pakistani/Indian) ethnic background. All four Somali patients have the P497S mutation, with one of the four being homozygous for the mutation. The three compound heterozygotes all have a novel mutation (P142T) and two of them have another change (Y428Y) that has never been described. Within the last two decades, Minnesota has become home to an estimated 40 000 Somali immigrants and their children (<1% of the total Minnesota population). New population demographics prompt careful analysis of case cohorts to identify specific groups at risk for rare inborn errors of metabolism.