A Voluntary Statewide Newborn Screening Pilot for Spinal Muscular Atrophy: Results from Early Check.

Prior to statewide newborn screening (NBS) for spinal muscular atrophy (SMA) in North Carolina, U.S.A., we offered voluntary screening through the Early Check (EC) research study. Here, we describe the EC experience from October 2018 through December 2020. We enrolled a total of 12,065 newborns and identified one newborn with 0 copies of SMN1 and two copies of SMN2, consistent with severe early onset of SMA. We also detected one false positive result, likely stemming from an unrelated blood disorder associated with a low white blood cell count. We evaluated the timing of NBS for babies enrolled prenatally (n = 932) and postnatally (n = 11,133) and reasons for delays in screening and reporting. Although prenatal enrollment led to faster return of results (median = 13 days after birth), results for babies enrolled postnatally were still available within a timeframe (median = 21 days after birth) that allowed the opportunity to receive essential treatment early in life. We evaluated an SMA q-PCR screening method at two separate time points, confirming the robustness of the assay. The pilot project provided important information about SMA screening in anticipation of forthcoming statewide expansion as part of regular NBS.

Evaluation of X-Linked Adrenoleukodystrophy Newborn Screening in North Carolina.

Importance: X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal genetic disorder in which an accumulation of very long-chain fatty acids leads to inflammatory demyelination in the central nervous system and to adrenal cortex atrophy. In 2016, X-ALD was added to the US Recommended Uniform Screening Panel. Objective: To evaluate the performance of a single-tier newborn screening assay for X-ALD in North Carolina. Design, Setting, and Participants: This diagnostic screening study was of all newborn dried blood spot specimens received in the North Carolina State Laboratory of Public Health between January 2 and June 1, 2018, excluding specimens of insufficient quantity or quality. A total of 52 301 specimens were screened for X-ALD using negative ionization high-performance liquid chromatography tandem mass spectrometry to measure C24:0- and C26:0-lysophosphatidylcholine concentrations. Sanger sequencing of the adenosine triphosphate-binding cassette subfamily D member 1 (ABCD1) gene was performed on screen-positive specimens. Exposures: A medical and family history, newborn physical examination, sequencing of ABCD1 on dried blood spot samples, and plasma analysis of very long-chain fatty acids were obtained for all infants with screen-positive results. Main Outcomes and Measures: The prevalence of X-ALD in North Carolina and the positive predictive value and false-positive rate for the first-tier assay were determined. Results: Of 52 301 infants tested (47.8% female, 50.6% male, and 1.7% other or unknown sex), 12 received screen-positive results. Of these 12 infants, 8 were confirmed with a genetic disorder: 3 male infants with X-ALD, 3 X-ALD-heterozygous female infants, 1 female infant with a peroxisome biogenesis disorder, and 1 female infant with Aicardi-Goutières syndrome. Four infants were initially classified as having false-positives results, including 3 female infants who were deemed unaffected and 1 male infant with indeterminate results on confirmatory testing. The positive predictive value for X-ALD or other genetic disorders for the first-tier assay was 67%, with a false-positive rate of 0.0057%. Conclusions and Relevance: This newborn screening pilot study reported results on 2 lysophosphatidylcholine analytes, identifying 3 male infants with X-ALD, 3 X-ALD-heterozygous female infants, and 3 infants with other disorders associated with increased very long-chain fatty acids. These results showed successful implementation in a public health program with minimal risk to the population. The findings will support other state laboratories planning to implement newborn screening for X-ALD and related disorders.

The North Carolina Experience with Mucopolysaccharidosis Type I Newborn Screening.

OBJECTIVE: To evaluate the performance of a 2-tiered newborn screening method for mucopolysaccharidosis type I (MPS I) in North Carolina. STUDY DESIGN: The screening algorithm included a flow injection analysis-tandem mass spectrometry assay as a first-tier screening method to measure α-L-iduronidase (IDUA) enzyme activity and Sanger sequencing of the IDUA gene on dried blood spots as a second-tier assay. The screening algorithm was revised to incorporate the Collaborative Laboratory Integrated Reports, an analytical interpretive tool, to reduce the false-positive rate. A medical history, physical examination, IDUA activity, and urinary glycosaminoglycan (GAG) analysis were obtained on all screen-positive infants. RESULTS: A total of 62 734 specimens were screened with 54 screen-positive samples using a cut-off of 15% of daily mean IDUA activity. The implementation of Collaborative Laboratory Integrated Reports reduced the number of specimens that screened positive to 19 infants. Of the infants identified as screen-positive, 1 had elevated urinary GAGs and a homozygous pathogenic variant associated with the severe form of MPS I. All other screen-positive infants had normal urinary GAG analysis; 13 newborns had pseudodeficiency alleles, 3 newborns had variants of unknown significance, and 2 had heterozygous pathogenic variants. CONCLUSIONS: An infant with severe MPS I was identified and referred for a hematopoietic stem cell transplant. Newborn IDUA enzyme deficiency is common in North Carolina, but most are due to pseudodeficiency alleles in infants with normal urinary GAG analysis and no evidence of disease. The pilot study confirmed the need for second-tier testing to reduce the follow-up burden.

Engaging Participants in Rare Disease Research: A Qualitative Study of Duchenne Muscular Dystrophy.

PURPOSE: Clinical trials in Duchenne muscular dystrophy (DMD) are increasing due to technical advances in genetics, muscle biology and muscle imaging, and translational science. Yet the ability to achieve and measure progress in clinical trials in DMD is severely constrained by recruitment difficulties and low levels of patient and family participation. Clinical trials that do not have full inclusion of patients may affect how well new therapies perform in clinical practice. METHODS: This study qualitatively investigated family-centered and clinician-based knowledge, attitudes, and perceptions of engagement in clinical research in DMD. Thirteen focus-group sessions (8 parent based and 5 clinician based) were held at 5 demographically and geographically diverse sites (Houston, Texas; Minneapolis, Minnesota; Pittsburgh, Pennsylvania; Sacramento, California; and Washington, DC). Thematic analysis was used for identifying patterns of meaning across the dataset. FINDINGS: Totals of 28 parents and 33 clinicians participated in innovative and thoughtful discussions regarding clinical research in DMD and approaches to eliciting family engagement. Five overarching themes emerged from our qualitative data. The theme of Information discussed the lack of accessible and coherent information, as well as the overabundance of fragmented information. The theme of Conversation demonstrated the importance of having open and in-depth dialogue about research with families in eliciting trust and obligation toward the research process. The Barriers and Incentives themes presented the parents' and clinicians' views of the life-altering sacrifices that families make to participate in research and ways to reduce these burdens. Under the Solutions theme, parents and clinicians also suggested innovative ways to incentivize families and clinics and thoughtful solutions to increase family engagement in research. IMPLICATIONS: Effective recruitment for clinical studies in rare diseases requires a truly committed and engaged study team, as well as the necessary resources to overcome the multitude of barriers that families face. A clearly delineated recruitment plan, developed together with families, should be the standard operating procedure during clinical trial development. Protocols utilizing direct family-centered strategies for providing information and for recruiting research participants in studies in rare diseases are essential.