Search

Individuals with ultrarare disorders pose a structural challenge for healthcare systems since expert clinical knowledge is required to establish diagnoses. In TRANSLATE NAMSE, a 3-year prospective study, we evaluated a novel diagnostic concept based on multidisciplinary expertise in Germany. Here we present the systematic investigation of the phenotypic and molecular genetic data of 1,577 patients who had undergone exome sequencing and were partially analyzed with next-generation phenotyping approaches. Molecular genetic diagnoses were established in 32% of the patients totaling 370 distinct molecular genetic causes, most with prevalence below 1:50,000. During the diagnostic process, 34 novel and 23 candidate genotype–phenotype associations were identified, mainly in individuals with neurodevelopmental disorders. Sequencing data of the subcohort that consented to computer-assisted analysis of their facial images with GestaltMatcher could be prioritized more efficiently compared with approaches based solely on clinical features and molecular scores. Our study demonstrates the synergy of using next-generation sequencing and phenotyping for diagnosing ultrarare diseases in routine healthcare and discovering novel etiologies by multidisciplinary teams.

IMPORTANCE: There is increasing evidence that early diagnosis and treatment are key for outcomes in infants with spinal muscular atrophy (SMA), and newborn screening programs have been implemented to detect the disease before onset of symptoms. However, data from controlled studies that reliably confirm the benefits of newborn screening are lacking. OBJECTIVE: To compare data obtained on patients with SMA diagnosed through newborn screening and those diagnosed after clinical symptom onset. DESIGN, SETTING, AND PARTICIPANTS: This nonrandomized controlled trial used data from the SMARTCARE registry to evaluate all children born between January 2018 and September 2021 with genetically confirmed SMA and up to 3 SMN2 copies. The registry includes data from 70 participating centers in Germany, Austria, and Switzerland. Data analysis was performed in February 2023 so that all patients had a minimal follow-up of 18 months. EXPOSURE: Patients born in 2 federal states in Germany underwent screening in a newborn screening pilot project. All other patients were diagnosed after clinical symptom onset. All patients received standard care within the same health care system. MAIN OUTCOMES: The primary end point was the achievement of motor milestones. RESULTS: A total of 234 children (123 [52.6%] female) were identified who met inclusion criteria and were included in the analysis: 44 (18.8%) in the newborn screening cohort and 190 children (81.2%) in the clinical symptom onset cohort. The mean (SD) age at start of treatment with 1 of the approved disease-modifying drugs was 1.3 (2.2) months in the newborn screening cohort and 10.7 (9.1) months in the clinical symptom onset cohort. In the newborn screening cohort, 40 of 44 children (90.9%) gained the ability to sit independently vs 141 of 190 (74.2%) in the clinical symptom onset cohort. For independent ambulation, the ratio was 28 of 40 (63.6%) vs 28 of 190 (14.7%). CONCLUSIONS AND RELEVANCE: This nonrandomized controlled trial demonstrated effectiveness of newborn screening for infants with SMA in the real-world setting. Functional outcomes and thus the response to treatment were significantly better in the newborn screening cohort compared to the unscreened clinical symptom onset group. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00012699

Numerous studies have consistently found that reduced SMN protein expression does not severely affect cognitive function in SMA patients. However, the average intelligence quotient of SMA patients has ranged above to below average in different studies. The cognitive development of SMA patients identified through newborn screening remains largely unknown. 40 of 47 eligible SMA patients (23 females/17 males) from 39 families identified through newborn screening between January 2018 and December 2020 underwent developmental testing using Bayley III (BSID) after the 2 years of age. The mean age was 29.25 months (23–42 months). 17 patients had 2, 11 patients had 3 and 12 patients had ≥4 copies of SMN2. cognitive scale: mean 94.55 (SD 24.01); language scale: mean 86.09 (SD 26.41); motor scale: 81.28 (SD 28.07). Overall, the cognitive scales show that 14 children were below average, 20 children were average and 6 children were above average. 10/14 children with below average scores had 2 SMN2 copies. The post-hocpairwise comparisons showed that the cognition main scale was significantly more sensitive to the number of SMN2 copies than the motor main scale of the BSID (MΔ= 10.27, p = 0.014). There is also evidence that cognition scored higher than the language main scale (MΔ= 7.11, p = 0.090). The impaired cognitive development of SMA children with 2 SMN2 copies, despite early initiation of therapy, underscores the critical role of the SMN protein in the early stages of brain development.

Now that targeted therapies for spinal muscular atrophy are available, attempts are being made worldwide to include screening for spinal muscular atrophy in general newborn screening. In Germany, after pilot projects from 2018–2021, it was included in the general newborn screening from October 2021. To ensure a smooth transition, criteria for follow-up were developed together with key stakeholders. At the beginning of the transition to nationwide screening, false positive findings were reported in 3 patients. After optimization of the screening method in the laboratories concerned, all findings have been subsequently confirmed. On average, the first presentation to a neuromuscular center occurred on day 12 of life, and in patients with 2 or 3 SMN2copies, therapy started on day 26 of life. Compared with the pilot project, there was no significant delay in timing.

PurposeARF1was previously implicated in periventricular nodular heterotopia (PVNH) in only five individuals and systematic clinical characterisation was not available. The aim of this study is to provide a comprehensive description of the phenotypic and genotypic spectrum of ARF1-related neurodevelopmental disorder.MethodsWe collected detailed phenotypes of an international cohort of individuals (n=17) with ARF1variants assembled through the GeneMatcher platform. Missense variants were structurally modelled, and the impact of several were functionally validated.ResultsDe novo variants (10 missense, 1 frameshift, 1 splice altering resulting in 9 residues insertion) in ARF1were identified among 17 unrelated individuals. Detailed phenotypes included intellectual disability (ID), microcephaly, seizures and PVNH. No specific facial characteristics were consistent across all cases, however microretrognathia was common. Various hearing and visual defects were recurrent, and interestingly, some inflammatory features were reported. MRI of the brain frequently showed abnormalities consistent with a neuronal migration disorder.ConclusionWe confirm the role of ARF1in an autosomal dominant syndrome with a phenotypic spectrum including severe ID, microcephaly, seizures and PVNH due to impaired neuronal migration.

Early treatment after genetic newborn screening (NBS) for SMA significantly improves outcomes in infantile SMA. However, there is no consensus in the SMA treatment community about early treatment initiation in patients with four copies of SMN2. Approach to a responsible treatment strategy for SMA patients with four SMN2copies detected in newborn screening. Inclusion criteria were a history of SMA diagnosed by NBS, age > 12 months at last examination, and diagnosis of four SMN2copies at confirmatory diagnosis. 21 patients with SMA and four SMN2copies were identified in German screening projects over a three-year period. In three of them, the SMN2copy number had to be corrected later, and three patients were lost to follow-up. Eight of the fifteen patients who were subject to long-term follow-up underwent presymptomatic therapy between 3 and 36 months of age and had no definite disease symptoms to date. Five of the other seven patients who underwent a strict follow-up strategy, showed clinical or electrophysiological disease onset between 1.5 and 4 years of age. In two of them, complete recovery was not achieved despite immediate initiation of treatment after the onset of the first symptoms. A remarkable proportion of patients with four copies of SMN2develop irreversible symptoms within the first four years of life, if a wait-and-see strategy is followed. These data argue for a proactive approach, i.e., early initiation of treatment in this subgroup of SMA patients.

Spinal Muscular Atrophy (SMA) is the most common neurodegenerative disease in childhood. New therapeutic interventions have been developed to interrupt rapid motor deterioration. The current standard of clinical evaluation for severely weak infants is the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), originally developed for SMA type 1. This test however, remains subjective and requires extensive training to be performed reliably. Proof of principle of the motion tracking method for capturing complex movement patterns in ten children with SMA. We have developed a system for tracking full-body motion in infants (KineMAT) using a commercially available, low-cost RGB-depth sensor. Ten patients with SMA (2–46 months of age; CHOP INTEND score 10–50) were recorded for 2 minutes during unperturbed spontaneous whole-body activity. Five predefined motion parameters representing 56 degrees of freedom of upper, lower extremities and trunk joints were correlated with CHOP INTEND scores using Pearson product momentum correlation (r). Test-retest analysis in two patients used descriptive statistics. 4/5 preselected motion parameters highly correlated with CHOP INTEND: 1. Standard deviation of joint angles (r = 0.959, test-retest range 1.3–1.9%), 2. Standard deviation of joint position (r = 0.933, test-retest range 2.9%), 3. Absolute distance of hand/foot travelled (r = 0.937, test-retest range 6–10.5%), 4. Absolute distance of hand/foot travelled against gravity (r = 0.923; test-retest range 4.8–8.5%). Markerless whole-body motion capture using the KineMAT proved to objectively capture motor performance in infants and children with SMA across different severity and ages.

Prompt treatment after genetic NBS for SMA substantially improves outcome in infantile SMA. However, deficiency of SMN-protein can cause damage of motor neurons even prior to birth. To describe the neurological status at the time of NBS and the reversibility of neurological deficits in a cohort of patients with only two copies of the SMN2gene. We present motor, respiratory, and bulbar outcomes of 21 SMA patients identified in newborn screening projects in Germany. Inclusion criteria was initiation of SMN targeted medication at less than 6 weeks of age and a minimum age of 9 months at last examination. Twelve patients (57%) developed completely normally, reaching motor milestones in time and having no bulbar or respiratory problems. Three children (14.5%) caught up after initial delay in motor development. Six patients (29%) developed proximal weakness despite early treatment: Three of them (14.5%) achieved the ability to walk with assistance and the other three (14.5%) showed an SMA type 2 phenotype at the age of 16–30 months. One patient (4.8%) had respiratory problems. Three children (14.5%) had mild chewing problems and two individuals (9.5%) needed feeding via gastrotube. Initial CHOP-INTEND values below 30 could be indicative of a less favourable outcome, whereas values above 50 could indicate a good outcome, however in-depth statistic due to the small case number is not predictive. More than 70% of SMA patients with two SMN2copies can achieve independent ambulation with immediate initiation of therapy. However, caregivers and paediatricians must be informed about the possibility of less favourable outcomes when discussing therapeutic strategies.

Background: Spinal Muscular Atrophy (SMA) is the most common neurodegenerative disease in childhood. New therapeutic interventions have been developed to interrupt rapid motor deterioration. The current standard of clinical evaluation for severely weak infants is the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), originally developed for SMA type 1. This test however, remains subjective and requires extensive training to be performed reliably.Objective: Proof of principle of the motion tracking method for capturing complex movement patterns in ten children with SMA.Methods: We have developed a system for tracking full-body motion in infants (KineMAT) using a commercially available, low-cost RGB-depth sensor. Ten patients with SMA (2–46 months of age; CHOP INTEND score 10–50) were recorded for 2 minutes during unperturbed spontaneous whole-body activity. Five predefined motion parameters representing 56 degrees of freedom of upper, lower extremities and trunk joints were correlated with CHOP INTEND scores using Pearson product momentum correlation (r). Test-retest analysis in two patients used descriptive statistics.Results: 4/5 preselected motion parameters highly correlated with CHOP INTEND: 1. Standard deviation of joint angles (r?=?0.959, test-retest range 1.3–1.9%), 2. Standard deviation of joint position (r?=?0.933, test-retest range 2.9%), 3. Absolute distance of hand/foot travelled (r?=?0.937, test-retest range 6–10.5%), 4. Absolute distance of hand/foot travelled against gravity (r?=?0.923; test-retest range 4.8–8.5%).Conclusions: Markerless whole-body motion capture using the KineMAT proved to objectively capture motor performance in infants and children with SMA across different severity and ages.

Given the novelty of gene replacement therapy with onasemnogene abeparvovec in spinal muscular atrophy, efficacy and safety data are limited, especially for children older than 24 months, those weighing more than 8·5 kg, and those who have received nusinersen. We aimed to provide real-world data on motor function and safety after gene replacement therapy in different patient subgroups.

Although the value of newborn screening (NBS) for early detection and treatment opportunity in SMA patients is generally accepted, there is still an ongoing discussion about the best strategy in children with 4 and more copies of the SMN2gene. This gene is known to be the most important but not the only disease modifier. In our SMA-NBS pilot project in Germany comprising 278,970 infants screened between January 2018 and November 2019 were 38 positive cases with a homozygous SMN1deletion. 40% of them had 4 or more SMN2copies. The incidence for homozygous SMN1deletion was 1 : 7350, which is within the known range of SMA incidence in Germany. Of the 15 SMA children with 4 SMN2copies, one child developed physical signs of SMA by the age of 8 months. Reanalysis of the SMN2 copy number by a different test method revealed 3 copies. Two children had affected siblings with SMA Type III, who were diagnosed only after detection of the index patient in the NBS. One had a positive family history with an affected aunt (onset of disease at the age of 3 years). Three families were lost to medical follow up; two because of socioeconomic reasons and one to avoid the psychological stress associated with the appointments. Decisions on how to handle patients with 4 SMN2copies are discussed in the light of the experience gathered from our NBS pilot SMA program.

Establishing nucleic acid-based assays for genetic newborn screening (NBS) provides the possibility to screen for genetically encoded diseases like spinal muscular atrophy (SMA), best before the onset of symptoms. Such assays should be easily scalable to 384-well reactions that make the screening of up to 2000 samples per day possible. We developed a test procedure based on a cleanup protocol for dried blood spots and a quantitative (q)PCR to screen for a homozygous deletion of exon 7 of the survival of motor neuron 1 gene (SMN1) that is responsible for >95% of SMA patients. Performance of this setup is evaluated in detail and tested on routine samples. Our cleanup method for nucleic acids from dried blood spots yields enough DNA for diverse subsequent qPCR applications. To date, we have applied this approach to test 213,279 samples within 18 months. Thirty patients were identified and confirmed, implying an incidence of 1:7109 for the homozygous deletion. Using our cleanup method, a rapid workflow could be established to prepare nucleic acids from dried blood spot cards. Targeting the exon 7 deletion, no invalid, false-positive, or false-negative results were reported to date. This allows timely identification of the disease and grants access to the recently introduced treatment options, in most cases before the onset of symptoms. Carriers are not identified, thus, there are no concerns of whether to report them.

Background. Next-generation sequencing (NGS) describes new powerful techniques of nucleic acid analysis, which allow not only disease gene identification diagnostics but also applications for transcriptome/methylation analysis and meta-genomics. NGS helps identify many monogenic epilepsy syndromes. Pediatric epilepsy patients can be tested using NGS epilepsy panels to diagnose them, thereby influencing treatment choices. The primary objective of this study was to evaluate the impact of genetic testing on clinical decision making in pediatric epilepsy patients. Methods. We completed a single-center retrospective cohort study of 91 patients (43 male) aged 19 years or less undergoing NGS with epilepsy panels differing in size ranging from 5 to 434 genes from October 2013 to September 2017. Results. During a mean time of 3.6 years between symptom onset and genetic testing, subjects most frequently showed epileptic encephalopathy (40%), focal epilepsy (33%), and generalized epilepsy (18%). In 16 patients (18% of the study population), “pathogenic” or “likely pathogenic” results according to ACMG criteria were found. Ten of the 16 patients (63%) experienced changes in clinical management regarding their medication and avoidance of further diagnostic evaluation, that is, presurgical evaluation. Conclusion. NGS epilepsy panels contribute to the diagnosis of pediatric epilepsy patients and may change their clinical management with regard to both preventing unnecessary and potentially harmful diagnostic procedures and management. Thus, the present data support the early implementation in order to adopt clinical management in selected cases and prevent further invasive investigations. Given the relatively small sample size and heterogeneous panels a larger prospective study with more homogeneous panels would be helpful to further determine the impact of NGS on clinical decision making.

Spinal muscular atrophy (SMA) is the most common neurodegenerative disease in childhood. The study was conducted to assess the impact of early detection of SMA by newborn screening (NBS) on the clinical course of the disease. Screening was performed in two federal states of Germany, Bavaria and North Rhine Westphalia, between January 2018 and February 2019. The incidence in the screening population was calculated as number of detected patients with a homozygous deletion in the SMN1-gene per number of screened patients. To get an idea about the incidence of newly diagnosed SMA in the year prior to screening a survey covering all neuropediatric centers in the state of Bavaria was conducted, identifying all SMA-cases in 2017 and 2018. Following positive NBS and confirmatory diagnostic test, treatment was advised according to the recommendations of the “American SMA NBS Multidisciplinary Working Group”. Immediate treatment with Nusinersen was recommended in children with 2 and 3 SMN2copies and a conservative strict follow-up strategy in children with ≥4 copies. All children underwent regular standardized neuropediatric examination, CHOP INTEND and HINE-2 testing as well as electrophysiological exams every 2-3 months. 165,525 children were screened. 22 cases of SMA were identified, meaning an incidence rate of 1:7524. SMN2copy number analysis showed 2 SMN2 copiesin 45% of patients, 3 SMN2 copiesin 19 % and 4 SMN2 copiesin 36%. These findings are confirmed in the most recent statistical data-cut from 31st August 2019 (incidence 1:7089, 2 SMN2copies in 44%, 3 in 15% and 4 in 38%). Comparison with up-to-date German data on SMA incidence and the Bavarian survey give evidence that NBS did not lead to a relevant increase in incidence. 10 patients with 2 or 3 SMN2copies were treated with Nusinersen, starting between 15– 39 days after birth, in 7/10 patients before onset of symptoms. Presymptomatically treated patients (age at last examination: 1– 12 months, median 8 months) showed no muscle weakness by the age of one month to one year. One child with 4 SMN2copies became symptomatic at the age of 8 months. Newborn screening, resulting in presymptomatic treatment, improves outcome in children with genetically proven SMA. Newborn screening for SMA should be introduced in all countries where therapy is available. An immediate therapy in cases with 4 SMN2copies should be considered.