A Historical and Current Review of Newborn Screening for Neuromuscular Disorders From Around the World: Lessons for the United States

Preconception or prenatal acceptance of SMN1 gene carrier screening and carrier rate of spinal muscular atrophy: a retrospective study in 18,818 reproductive age women in Wuhan area of China

OBJECTIVE

Spinal muscular atrophy (SMA) is an autosomal recessive disorder mainly affecting the neuromuscular system, which seriously threatens the life and health of patients. But few studies have reported the acceptance rate of SMA gene screening and SMA carrier rate in China. The present study aimed to clarify the two issues in China through a retrospective analysis of 18,818 reproductive age women in Wuhan area of China.

METHODS

The copy number (CN) of exons 7 and 8 in survival motor neuron 1 (SMN1) gene was detected by real-time quantitative PCR, and the results were verified by multiplex ligation-dependent probe amplification.

RESULTS

Carrier screening was offered to 44,953 women of childbearing age in our medical center from March, 2018, to February, 2022, of whom 18,818 were enrolled in the program. A total of 336 women were identified as carriers (1.73%; 326/18,808; without fertility history of the children with SMA). Among 18,818 reproductive age women, 286 spouses (85.12%; 286/336) were successfully recalled for screening. The results showed 17 couples at high risk of having children with SMA, of whom prenatal diagnosis was implemented in 11, and 6 fetuses were identified with SMA. All the 5 pregnant women bearing the 6 SMA fetuses chose to terminate the pregnancy by artificial abortion.

CONCLUSION

Reproductive age women and their spouses in Wuhan area showed a positive attitude toward general screening for SMA carriers. Given the high early mortality of children with SMA, screening for SMA carriers in women of reproductive age is necessary and feasible.

Clinical and biochemical footprints of inherited metabolic disorders: X. Metabolic myopathies

Metabolic myopathies are characterized by the deficiency or dysfunction of essential metabolites or fuels to generate energy for muscle contraction; they most commonly manifest with neuromuscular symptoms due to impaired muscle development or functioning. We have summarized associations of signs and symptoms in 358 inherited metabolic diseases presenting with myopathies. This represents the tenth of a series of articles attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Time to diagnosis of Duchenne muscular dystrophy remains unchanged: Findings from the Muscular Dystrophy Surveillance, Tracking, and Research Network, 2000-2015

INTRODUCTION/AIMS

With current and anticipated disease-modifying treatments, including gene therapy, an early diagnosis for Duchenne muscular dystrophy (DMD) is crucial to assure maximum benefit. In 2009, a study from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) showed an average diagnosis age of 5 years among males with DMD born from January 1, 1982 to December 31, 2000. Initiatives were implemented by the US Centers for Disease Control and Prevention (CDC) and patient organizations to reduce time to diagnosis. We conducted a follow-up study in a surveillance cohort born after January 1, 2000 to determine whether there has been an improvement in time to diagnosis.

METHODS

We assessed the age of diagnosis among males with DMD born from January 1, 2000 to December 31, 2015 using data collected by six US MD STARnet surveillance sites (Colorado, Iowa, western New York State, the Piedmont region of North Carolina, South Carolina, and Utah). The analytic cohort included 221 males with definite or probable DMD diagnosis without a documented family history. We computed frequency count and percentage for categorical variables, and mean, median, and standard deviation (SD) for continuous variables.

RESULTS

The mean [median] ages in years of diagnostic milestones were: first signs, 2.7 [2.0]; first creatine kinase (CK), 4.6 [4.6]; DNA/muscle biopsy testing, 4.9 [4.8]; and time from first signs to diagnostic confirmation, 2.2 [1.4].

DISCUSSION

The time interval between first signs of DMD and diagnosis remains unchanged at 2.2 years. This results in lost opportunities for timely genetic counseling, implementation of standards of care, initiation of glucocorticoids, and participation in clinical trials.

Parents as informal caregivers of children and adolescents with spinal muscular atrophy: a systematic review of quantitative and qualitative data on the psychosocial situation, caregiver burden, and family needs

BACKGROUND

Spinal muscular atrophy (SMA) is a rare degenerative neuromuscular disease, mostly occurring in infants and children, leading to muscle wasting and weakness, and premature death. Due to new developments of multiple disease-modifying treatments within the last years, the interest of research in patients affected by SMA increased steadily. However, the psychosocial situation of parents as informal caregivers is still rarely addressed.

OBJECTIVES

This review aims to highlight quantitative and qualitative data about the psychosocial situation, caregiver burden, and needs of parents as informal caregivers for children and adolescents with SMA.

METHODS

A systematic literature review was performed including quantitative and qualitative original studies focusing on different psychosocial aspects and outcomes for parents of children and adolescents < 21 years of age with SMA type I-IV (PROSPERO; registration number CRD42020219020). We searched the following databases in November 2020 with a research update in August 2021: MEDLINE, CINAHL, PsycINFO and Web of Science.

RESULTS

In total, 24 articles from 23 studies were selected for inclusion (15 quantitative studies, 7 articles from 6 qualitative studies, 2 mixed methods studies). The synthesis of included studies shows multiple sources of psychosocial burden for parents of children and adolescents affected by SMA: Most studies found reduced levels of quality of life, moderate to high levels of caregiver burden and distress, as well as physical and mental health symptoms. Further, findings indicate several unmet family needs regarding information, care coordination, treatment decisions, financial support, and adequate supportive care services.

CONCLUSION

Parents of children and adolescents with SMA face multiple sources of psychosocial stressors, caregiver burden and various unmet family needs. To unburden families, the needs of parents as caregivers should be included in integrated care paths for SMA to improve their psychosocial situation and thus their ability to care for their children and to treat or prevent physical and mental health problems due to overburdening. Future research should focus not only on quality of life and on caregiving-related burden but should also examine the clinical relevance of reported symptoms to support the implementation of adequate support services for families affected by SMA.

A Qualitative Study: Mothers' Experiences of Their Child's Late-Onset Pompe Disease Diagnosis Following Newborn Screening

Pompe disease was added to the United States recommended uniform screening panel in 2015 to avoid diagnostic delay and implement prompt treatment, specifically for those with infantile-onset Pompe disease (IOPD). However, most newborns with abnormal newborn screening (NBS) for Pompe disease have late-onset Pompe disease (LOPD). An early diagnosis of LOPD raises the question of when symptoms will arise which is challenging for parents, patients, and providers managing an LOPD diagnosis. This study aimed to characterize mothers' experiences of their child's LOPD diagnosis and medical monitoring. A qualitative descriptive approach was chosen to gain an in-depth understanding of parental experiences. Eight mothers were interviewed about their experiences with positive NBS and diagnosis, experiences with living with the diagnosis, and experiences with medical monitoring. Interview transcripts were analyzed through conventional content analysis. Negative emotions like fear were more frequent with communication of NBS results. Participants expressed uncertainty surrounding age of symptom onset and the future. The medical monitoring experience increased worry but participants expressed that being vigilant with management reassured them. Parental emotions shifted to thankfulness and reassurance with time and education. These findings can provide guidance to providers about the psychosocial implications of receiving positive NBS results and an LOPD diagnosis.

Facing Muscular Dystrophy During Covid-19 Pandemic: The Role of Support Associations and Spirituality

Several researches in scientific literature analyze the theme of Muscular Dystrophy (MD), As well as many others focus on the theme of the Covid-19 pandemic; however, there is a rather limited number of studies that analyse how the pandemic has affected the life of people suffering from MD, especially during the time of the first lockdown in the spring of 2020. The present study has applied a qualitative research design with the aim to investigate how patients with MD have lived the social restrictions imposed for the contagion containment and whether the assistance of associations for their support has contributed to make the participants feel closer or more distant from the spiritual dimension. The analysis involved 12 participants, and they were presented with a semi-structured interview. The data obtained from the interviews have been analysed through a thematic analysis from which 4 thematic areas have emerged: (1) the impact of the pandemic on an emotional level; (2) the illness management and the role of family; (3) the role of the associations; (4) aspects related to spirituality. The crucial role that the closeness of family and the activities promoted remotely by the associations for patients' support has emerged, since they have allowed the participants to feel united by something beyond, to discover new aspects of themselves, to give more value to Life and to move closer to their spiritual dimension.

Complexity of skeletal muscle degeneration: multi-systems pathophysiology and organ crosstalk in dystrophinopathy

Duchenne muscular dystrophy is a highly progressive muscle wasting disorder due to primary abnormalities in one of the largest genes in the human genome, the DMD gene, which encodes various tissue-specific isoforms of the protein dystrophin. Although dystrophinopathies are classified as primary neuromuscular disorders, the body-wide abnormalities that are associated with this disorder and the occurrence of organ crosstalk suggest that a multi-systems pathophysiological view should be taken for a better overall understanding of the complex aetiology of X-linked muscular dystrophy. This article reviews the molecular and cellular effects of deficiency in dystrophin isoforms in relation to voluntary striated muscles, the cardio-respiratory system, the kidney, the liver, the gastrointestinal tract, the nervous system and the immune system. Based on the establishment of comprehensive biomarker signatures of X-linked muscular dystrophy using large-scale screening of both patient specimens and genetic animal models, this article also discusses the potential usefulness of novel disease markers for more inclusive approaches to differential diagnosis, prognosis and therapy monitoring that also take into account multi-systems aspects of dystrophinopathy. Current therapeutic approaches to combat muscular dystrophy are summarised.

Health care practitioners' experience-based opinions on providing care after a positive newborn screen for Pompe disease

The addition of Pompe disease (PD) and other conditions with later-onset forms to newborn screening (NBS) in the United States (US) has been controversial. NBS technology cannot discern infantile-onset PD (IOPD) from later-onset PD (LOPD) without clinical follow-up. This study explores genetic health care practitioners' (HCPs) experiences and challenges providing NBS patient care throughout the US and their resultant opinions on NBS for PD. An online survey was distributed to genetic counselors, geneticists, NBS follow-up care coordinators, and nurse practitioners caring for patients with positive NBS results for PD. Analysis of 78 surveys revealed the majority of participating HCPs support inclusion of PD on NBS. Almost all HCPs (93.3%) feel their state has sufficient resources to provide follow-up medical care for IOPD; however, only three-fourths (74.6%) believed this for LOPD. Common barriers included time lag between NBS and confirmatory results, insurance difficulties for laboratory testing, and family difficulties in seeking medical care. HCPs more frequently encountered barriers providing care for LOPD than IOPD (53.9% LOPD identified ≥3 barriers, 31.1% IOPD). HCPs also believe creation of a population of presymptomatic individuals with LOPD creates a psychological burden on the family (87.3% agree/strongly agree), unnecessary medicalization of the child (63.5% agree/strongly agree), and parental hypervigilance (68.3% agree/strongly agree). Opinions were markedly divided on the use of reproductive benefit as a justification for NBS. Participants believe additional education for pediatricians and other specialists would be beneficial in providing care for patients with both IOPD and LOPD, in addition to the creation of evidence-based official guidelines for care and supportive resources for families with LOPD.

Urinary Titin Is a Novel Biomarker for Muscle Atrophy in Nonsurgical Critically Ill Patients: A Two-Center, Prospective Observational Study

OBJECTIVES

Although skeletal muscle atrophy is common in critically ill patients, biomarkers associated with muscle atrophy have not been identified reliably. Titin is a spring-like protein found in muscles and has become a measurable biomarker for muscle breakdown. We hypothesized that urinary titin is useful for monitoring muscle atrophy in critically ill patients. Therefore, we investigated urinary titin level and its association with muscle atrophy in critically ill patients.

DESIGN

Two-center, prospective observational study.

SETTING

Mixed medical/surgical ICU in Japan.

PATIENTS

Nonsurgical adult patients who were expected to remain in ICU for greater than 5 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Urine samples were collected on days 1, 2, 3, 5, and 7 of ICU admission. To assess muscle atrophy, rectus femoris cross-sectional area and diaphragm thickness were measured with ultrasound on days 1, 3, 5, and 7. Secondary outcomes included its relationship with ICU-acquired weakness, ICU Mobility Scale, and ICU mortality. Fifty-six patients and 232 urinary titin measurements were included. Urinary titin (normal range: 1-3 pmol/mg creatinine) was 27.9 (16.8-59.6), 47.6 (23.5-82.4), 46.6 (24.4-97.6), 38.4 (23.6-83.0), and 49.3 (27.4-92.6) pmol/mg creatinine on days 1, 2, 3, 5, and 7, respectively. Cumulative urinary titin level was significantly associated with rectus femoris muscle atrophy on days 3-7 (p ≤ 0.03), although urinary titin level was not associated with change in diaphragm thickness (p = 0.31-0.45). Furthermore, cumulative urinary titin level was associated with occurrence of ICU-acquired weakness (p = 0.01) and ICU mortality (p = 0.02) but not with ICU Mobility Scale (p = 0.18).

CONCLUSIONS

In nonsurgical critically ill patients, urinary titin level increased 10-30 times compared with the normal level. The increased urinary titin level was associated with lower limb muscle atrophy, occurrence of ICU-acquired weakness, and ICU mortality.

Opinions of adults affected with later-onset lysosomal storage diseases regarding newborn screening: A qualitative study

Lysosomal storage diseases (LSDs) are a heterogeneous group of conditions causing substrate accumulation leading to progressive organ damage. Newborn screening (NBS) for several LSDs has become available in recent years due to advances in technology and treatment availability. While early initiation of treatment is lifesaving for those with infantile presentations, controversy continues regarding diagnosis of milder, later-onset diseases in infancy, including creation of pre-symptomatic populations of 'patients-in-waiting', the potential for medicalization, stigmatization, and/or discrimination. In-depth interviews were conducted with 36 adults [11 with Fabry disease (FD), 8 with Gaucher disease (GD), and 17 with late-onset Pompe disease (LOPD)], to determine their perspectives on NBS for their respective conditions. Thirty-four of 36 participants were in favor of NBS; both participants not in favor had GD1. Emergent themes influencing participants favorably toward NBS included earlier age of onset, a long diagnostic odyssey, less efficacious treatment, and the desire to have made different life decisions (e.g., relationships, career, or lifestyle) with the knowledge of their diagnosis. Concerns about insurance discrimination and psychological or physical burdens were associated with less favorable opinions of NBS. The ability for parents to make future reproductive decisions based their child's NBS result was considered favorably by some participants and unfavorably by others. Participants' specific condition (GD1, FD, or LOPD) contributed to these experiences differently. Participants with LOPD and FD favored NBS to initiate earlier treatment and prevent irreversible organ damage, whereas fewer patients with GD1 mentioned this benefit. Participants with LOPD had the longest diagnostic odyssey, while those with FD were more likely to report feeling misunderstood and experiencing accusations of malingering, both contributing to favorable views of NBS. Results expand prior quantitative findings by illuminating how participants' lived experiences can shape opinions about NBS. By understanding how currently affected individuals perceive the lifelong impact of a NBS result, genetic counselors can provide better anticipatory guidance to the parents of individuals diagnosed with a later-onset LSD by NBS.

Neonatal and carrier screening for rare diseases: how innovation challenges screening criteria worldwide

Screening for rare diseases first began more than 50 years ago with neonatal bloodspot screening (NBS) for phenylketonuria, and carrier screening for Tay-Sachs disease, sickle cell anaemia and β-thalassaemia. NBS's primary aim is health gain for children, while carrier screening enables autonomous reproductive choice. While screening can be beneficial, it also has the potential to cause harm and thus decisions are needed on whether a specific screening is worthwhile. These decisions are usually based on screening principles and criteria. Technological developments, both treatment driven and test driven, have led to expansions in neonatal screening and carrier screening. This article demonstrates how the dynamics and expansions in NBS and carrier screening have challenged four well-known screening criteria (treatment, test, target population and programme evaluation), and the decision-making based on them. We show that shifting perspectives on screening criteria for NBS as well as carrier screening lead to converging debates in these separate fields. For example, the child is traditionally considered to be the beneficiary in NBS, but the family and society can also benefit. Vice versa, carrier screening may be driven by disease prevention, rather than reproductive autonomy, raising cross-disciplinary questions regarding potential beneficiaries and which diseases to include. In addition, the stakeholders from these separate fields vary: Globally NBS is often governed as a public health programme while carrier screening is usually available via medical professionals. The article concludes with a call for an exchange of vision and knowledge among all stakeholders of both fields to attune the dynamics of screening.

"We needed this": perspectives of parents and healthcare professionals involved in a pilot newborn screening program for spinal muscular atrophy

BACKGROUND

Newborn screening (NBS) for spinal muscular atrophy (SMA) is a recognised model through which health outcomes can be improved. However, perspectives of parents and healthcare professionals (HCPs) involved in such programs are largely unknown.

METHODS

A pilot program for SMA ran from August 2018-July 2020. Using a mixed-methods convergent methodology, we used a self-administered questionnaire to understand parents' perceptions and psychological impact of the program from diagnosis to treatment. We thematically analysed successes/challenges encountered by HCPs and recommendations for service improvement from both participant groups.

FINDINGS

202,388 infants were screened for SMA and the perceptions of 44 parents and HCPs affected by a positive result in eighteen newborns was ascertained. Parents (n=29, 100%) were satisfied with NBS for SMA. Although screen-positive result was distressing for all parents, quality of life improved over time [CarerQoL-7D baseline median score 4 (SD=1.4) vs six-month median score 8 (SD=1.3), p<0.001)]. Challenges for HCPs included managing the time-critical nature of the pathway whilst remaining cognisant of limitations associated with the predictive screening test.

INTERPRETATION

Interpretation: NBS for SMA fulfils criteria for population-wide screening. Net benefits are acknowledged by stakeholders to optimise lifelong outcomes. Harms including psychological distress associated with a screen-positive result may be managed by targeted psychosocial support, information provision and a personalised model of care together strengthening healthcare systems.

FUNDING

The NSW Pilot NBS study was funded by Luminesce Alliance. Dr Kariyawasam received funding from the RTP Scholarship, University of New South Wales and The Freedman Family Foundation Scholarship, Sydney Children's Hospital Foundation.

Survey on patients' organisations' knowledge and position paper on screening for inherited neuromuscular diseases in Europe

BACKGROUND

The development of new genetic testing methods and the approval of the first treatments raises questions regarding when and how to perform screening for inherited neuromuscular conditions. Screening directives and access to the different techniques is not uniform across Europe. The patient advisory board of the European reference network for rare neuromuscular diseases (NMD) conducted a qualitative study to understand the state of play of screening for inherited NMD in Europe and patients' needs.

RESULTS

We collected answers from 30 patient organisations (POs) from 18 European countries. Fifteen acknowledge the existence of pre-implantation genetic diagnosis in their country. Regarding prenatal screening, we had 25 positive answers and 5 negative ones. Twenty-four POs mentioned that newborn screening was available in their country. We had some contradictory answers from POs from the same country and in some cases; diseases said to be part of the screening programmes were not hereditary disorders. Twenty-eight organisations were in favour of screening tests. The reasons for the two negative answers were lack of reimbursement and treatment, religious beliefs and eventual insurance constrains. Most POs (21) were in favour of systematic screening with the option to opt-out. Regarding the timing for screening, "at birth", was the most consensual response. The main priority to perform screening for NMDs was early access to treatment, followed by shorter time to diagnostic, preventive care and genetic counselling.

CONCLUSIONS

This is the first study to assess knowledge and needs of POs concerning screening for NMDs. The knowledge of POs regarding screening techniques is quite uneven. This implies that, even in communities highly motivated and knowledgeable of the conditions they advocate for, there is a need for better information. Differences in the responses to the questions "how and when to screen" shows that the screening path depends on the disease and the presence of a disease modifying treatment. The unmet need for screening inherited NMDs should follow an adaptive pathway related to the fast moving medical landscape of NMDs. International coordination leading to a common policy would certainly be a precious asset tending to harmonize the situation amongst European countries.

Diagnostic challenges in metabolic myopathies

INTRODUCTION

Metabolic myopathies comprise a clinically etiological diverse group of disorders caused by defects in cellular energy metabolism including the breakdown of carbohydrates and fatty acids, which include glycogen storage diseases and fatty acid oxidation disorders. Their wide clinical spectrum ranges from infantile severe multisystemic disorders to adult-onset myopathies. To suspect in adults these disorders, clinical features such as exercise intolerance and recurrent myoglobinuria need investigation while another group presents fixed weakness and cardiomyopathy as a clinical pattern.

AREAS COVERED

In metabolic myopathies, clinical manifestations are important to guide diagnostic tests used in order to lead to the correct diagnosis. The authors searched in literature the most recent techniques developed. The authors present an overview of the most common phenotypes of Pompe disease and what is currently known about the mechanism of ERT treatment. The most common disorders of lipid metabolism are overviewed, with their possible dietary or supplementary treatments.

EXPERT COMMENTARY

The clinical suspicion is the clue to conduct in-depth investigations in suspected cases of metabolic myopathies that lead to the final diagnosis with biochemical molecular studies and often nowadays by the use of Next Generation Sequencing (NGS) to determine gene mutations.

Ethical and social implications of approaching death prediction in humans - when the biology of ageing meets existential issues

BACKGROUND

The discovery of biomarkers of ageing has led to the development of predictors of impending natural death and has paved the way for personalised estimation of the risk of death in the general population. This study intends to identify the ethical resources available to approach the idea of a long-lasting dying process and consider the perspective of death prediction. The reflection on human mortality is necessary but not sufficient to face this issue. Knowledge about death anticipation in clinical contexts allows for a better understanding of it. Still, the very notion of prediction and its implications must be clarified. This study outlines in a prospective way issues that call for further investigation in the various fields concerned: ethical, psychological, medical and social.

METHODS

The study is based on an interdisciplinary approach, a combination of philosophy, clinical psychology, medicine, demography, biology and actuarial science.

RESULTS

The present study proposes an understanding of death prediction based on its distinction with the relationship to human mortality and death anticipation, and on the analogy with the implications of genetic testing performed in pre-symptomatic stages of a disease. It leads to the identification of a multi-layered issue, including the individual and personal relationship to death prediction, the potential medical uses of biomarkers of ageing, the social and economic implications of the latter, especially in regard to the way longevity risk is perceived.

CONCLUSIONS

The present study work strives to propose a first sketch of what the implications of death prediction as such could be - from an individual, medical and social point of view. Both with anti-ageing medicine and the transhumanist quest for immortality, research on biomarkers of ageing brings back to the forefront crucial ethical matters: should we, as human beings, keep ignoring certain things, primarily the moment of our death, be it an estimation of it? If such knowledge was available, who should be informed about it and how such information should be given? Is it a knowledge that could be socially shared?

Spinal Muscular Atrophy: Past, Present, and Future

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease caused by deletions or mutations in the survival motor neuron (SMN1) gene. SMA is characterized by loss of lower motor neurons (anterior horn cells) in the spinal cord and brainstem nuclei, leading to progressive symmetrical muscle weakness and atrophy. It affects approximately 1 in 6,000 to 1 in 10,000 individuals and is the most common inherited cause of childhood mortality, but this may soon change given recent developments. In December 2016, nusinersen, an antisense oligonucleotide drug, was approved by the United States Food and Drug Administration for the treatment of SMA, and in July 2018, SMA was added to the recommended uniform screening panel, a list of conditions that all states are encouraged to include in their newborn screening (NBS) panels. In this review, we begin with a brief clinical history of the diagnosis of SMA, discuss the current SMA clinical classification system, describe the current treatment, and discuss evolving treatment guidelines. We then discuss the path to include SMA in NBS programs as well as the controversies it engenders because the variability in age at symptom onset means early identification of asymptomatic patients who will not require therapy for years or decades. We also consider alternate population screening opportunities. Next, we consider experimental treatments. We conclude by supporting NBS for SMA with the caveat that a long-term follow-up registry is ethically essential to ensure that the benefits outweigh the harms for all screened infants, including those with milder and/or later-onset forms of SMA.

Is it the right time for an infant screening for Duchenne muscular dystrophy?

Newborn screening (NBS) is an essential, preventive public health programme for early identification of disorders whose early treatment can lead to significant reduction in morbidity and mortality. NBS for Duchenne muscular dystrophy (DMD) has been a controversial matter for many years, because of false positives, the lack of effective drugs and the need of more data about screening efficacy. The still high diagnostic delay of DMD and the current availability of drugs such as steroid, ataluren, eteplirsen, golodirsen and forthcoming new drugs, improving the clinical conditions if early started, make appropriate to begin a concrete discussion between stakeholders to identify best practice for DMD screening. A two-step system CK/DNA screening programme is presented to be performed in male infants aged between 6 months and 42 months involving more than 30,000 male infants. Five to eight DMD subjects are believed to be diagnosed. The pilot project would give the opportunity to test in a small population the feasibility of an infant screening programme, which in the near future could be applicable to an entire country.

Epidemiology of rare diseases detected by newborn screening in the Czech Republic

OBJECTIVES

Presymptomatic detection of patients with rare diseases (RD), defined by a population frequency less than 1 : 2,000, is the task of newborn screening (NBS). In the Czech Republic (CZ), currently eighteen RD are screened: phenylketonuria/hyperphenylalaninemia (PKU/HPA), congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), cystic fibrosis (CF), medium chain acyl-CoA dehydrogenase deficiency (MCADD), long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), very long chain acyl-CoA dehydrogenase deficiency (VLCADD), carnitine palmitoyl transferase I and II deficiency (CPTID, CPTIID), carnitine-acylcarnitine translocase deficiency (CACTD), maple syrup urine disease (MSUD), glutaric aciduria type I (GA I), isovaleryl-CoA dehydrogenase deficiency (IVA), argininemia (ARG), citrullinemia (CIT), biotinidase deficiency (BTD), cystathionine beta-synthase-deficient homocystinuria (CBSD HCU), and methylenetetrahydrofolate reductase deficiency homocystinuria (MTHFRD HCU). The aim was to analyze the prevalence of RD screened by NBS in CZ.

METHODS

We examined the NBS programme in CZ from 1 January 2010 to 31 December 2017, which covered 888,891 neonates. Dried blood spots were primarily analyzed using fluorescence immuno-assay, tandem mass spectrometry and fluorimetry.

RESULTS

The overall prevalence of RD among the neonate cohort was 1 : 1,043. Individually, 1 : 2,877 for CH, 1 : 5,521 for PKU/HPA, 1 : 6,536 for CF (1 : 5,887 including false negative patients), 1 : 12,520 for CAH, 1 : 22,222 for MCADD, 1 : 80,808 for LCHADD, 1 : 177,778 for GA I, 1 : 177,778 for IVA, 1 : 222,223 for VLCADD, 1 : 296,297 for MSUD, 1 : 8,638 for BTD, and 1 : 181,396 for CBSD HCU.

CONCLUSIONS

The observed prevalence of RD, based on NBS, corresponds to that expected, more precisely it was higher for BTD and lower for MSUD, IVA, CBSD HCU, MCADD and VLCADD. Early detection of rare diseases by means of NBS is an effective secondary prevention tool.

"Be an ambassador for change that you would like to see": a call to action to all stakeholders for co-creation in healthcare and medical research to improve quality of life of people with a neuromuscular disease

Background

Patient and public involvement for co-creation is increasingly recognized as a valuable strategy to develop healthcare research targeting patients’ real needs. However, its practical implementation is not as advanced and unanimously accepted as it could be, due to cultural differences and complexities of managing healthcare programs and clinical studies, especially in the rare disease field.

Main body

The European Neuromuscular Centre, a European foundation of patient organizations, involved its key stakeholders in a special workshop to investigate the position of the neuromuscular patient community with respect to healthcare and medical research to identify and address gaps and bottlenecks. The workshop took place in Milan (Italy) on January 19–20, 2018, involving 45 participants who were mainly representatives of the patient community, but also included experts from clinical centers, industry and regulatory bodies. In order to provide practical examples and constructive suggestions, specific topics were identified upfront. The first set of issues concerned the quality of life at specific phases of a patient’s life, such as at the time of diagnosis or during pediatric to adult transition, and patient involvement in medical research on activities in daily living including patient reported outcome measures. The second set of issues concerned the involvement of patients in the management of clinical research tools, such as registries and biobanks, and their participation in study design or marketing authorization processes. Introductory presentations were followed by parallel working group sessions, to gain constructive contributions from all participants. The concept of shared decision making was used to ensure, in discussions, a partnership-based identification of the wishes and needs of all stakeholders involved, and the “ladder of participation” tool served as a model to evaluate the actual and the desired level of patients’ involvement in all topics addressed. A general consensus on the outcome of the meeting was collected during the final plenary session.

This paper reports the outcome of the workshop and the specific suggestions derived from the analysis of the first set of topics, related to quality of life. The outcomes of the second set of topics are reported elsewhere and are only briefly summarized herein for the sake of completeness.

Conclusions

The neuromuscular community proved to be very active and engaged at different levels in the healthcare initiatives of interest. The workshop participants critically discussed several topics, providing practical examples where different stakeholders could play a role in making a change and bridging gaps. Overall, they indicated the need for education of all stakeholders for better communication, where everyone should become an ambassador to promote real change. Support should also come from institutions and healthcare bodies both at structural and economic level.

Impact of newborn screening for very-long-chain acyl-CoA dehydrogenase deficiency on genetic, enzymatic, and clinical outcomes

Most infants with very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD) identified by newborn screening (NBS) are asymptomatic at the time of diagnosis and remain asymptomatic. If this outcome is due to prompt diagnosis and initiation of therapy, or because of identification of individuals with biochemical abnormalities who will never develop symptoms, is unclear. Therefore, a 10-year longitudinal national cohort study of genetically confirmed VLCADD patients born before and after introduction of NBS was conducted. Main outcome measures were clinical outcome parameters, acyl-CoA dehydrogenase very long chain gene analysis, VLCAD activity, and overall capacity of long-chain fatty acid oxidation (LC-FAO flux) in lymphocytes and cultured skin fibroblasts. Median VLCAD activity in lymphocytes of 54 patients, 21 diagnosed pre-NBS and 33 by NBS was, respectively, 5.4% (95% confidence interval [CI]: 4.0-8.3) and 12.6% (95% CI: 10.7-17.7; P < 0.001) of the reference mean. The median LC-FAO flux was 33.2% (95% CI: 22.8-48.3) and 41% (95% CI: 40.8-68; P < 0.05) of the control mean, respectively. Clinical characteristics in 23 pre-NBS and 37 NBS patients revealed hypoglycemic events in 12 vs 2 patients, cardiomyopathy in 5 vs 4 patients and myopathy in 14 vs 3 patients. All patients with LC-FAO flux <10% developed symptoms. Of the patients with LC-FAO flux >10% 7 out of 12 diagnosed pre-NBS vs none by NBS experienced hypoglycemic events. NBS has a clear beneficial effect on the prevention of hypoglycemic events in patients with some residual enzyme activity, but does not prevent hypoglycemia nor cardiac complications in patients with very low residual enzyme activity. The effect of NBS on prevalence and prevention of myopathy-related complications remains unclear.

Titin fragment in urine: A noninvasive biomarker of muscle degradation

Titin/connectin, encoded by the TTN gene, is the largest protein in humans. It acts as a molecular spring in the sarcomere of striated muscles. Although titin is degraded in the skeletal muscles of patients with muscular dystrophies, studies of titin have been limited by its mammoth size. Mutations in the TTN gene have been detected not only in skeletal muscle diseases but in cardiac muscle diseases. TTN mutations result in a wide variety of phenotypes. Recent proteome analysis has found that titin fragments are excreted into the urine of patents with Duchenne muscular dystrophy (DMD). Enzyme-linked immunosorbent assays (ELISAs) have shown that urinary titin is a useful noninvasive biomarker for the diagnosis and screening of not only DMD, but also of neuromuscular diseases, for predicting the outcome of cardiomyopathy and for evaluating physical activities. The development of ELISA systems to measure urinary titin has opened a door to studying muscle degradation directly and noninvasively. This review provides current understanding of urinary titin and future prospects for measuring this protein.

Éthique et innovation thérapeutique

Disposer de médicaments innovants pour soigner les maladies neuromusculaires marque incontestablement un tournant historique. Ce bond en avant scientifique suscite bien des interrogations éthiques, qu’elles concernent la prise en charge des patients, la participation aux essais cliniques ou encore le dépistage néonatal. Autant de pistes de réflexion ouvertes, en trois questions.

Ethics in genetic counselling

Difficult ethical issues arise for patients and professionals in medical genetics, and often relate to the patient's family or their social context. Tackling these issues requires sensitivity to nuances of communication and a commitment to clarity and consistency. It also benefits from an awareness of different approaches to ethical theory. Many of the ethical problems encountered in genetics relate to tensions between the wishes or interests of different people, sometimes even people who do not (yet) exist or exist as embryos, either in an established pregnancy or in vitro. Concern for the long-term welfare of a child or young person, or possible future children, or for other members of the family, may lead to tensions felt by the patient (client) in genetic counselling. Differences in perspective may also arise between the patient and professional when the latter recommends disclosure of information to relatives and the patient finds that too difficult, or when the professional considers the genetic testing of a child, sought by parents, to be inappropriate. The expectations of a patient's community may also lead to the differences in perspective between patient and counsellor. Recent developments of genetic technology permit genome-wide investigations. These have generated additional and more complex data that amplify and exacerbate some pre-existing ethical problems, including those presented by incidental (additional sought and secondary) findings and the recognition of variants currently of uncertain significance, so that reports of genomic investigations may often be provisional rather than definitive. Experience is being gained with these problems but substantial challenges are likely to persist in the long term.

Newborn screening for Pompe disease: impact on families

Pompe disease (PD) is an autosomal recessive lysosomal storage disorder causing progressive glycogen accumulation in muscles, with variability in age of onset and severity. For infantile-onset PD (IOPD), initiation of early treatment can be life-saving; however, current newborn screening (NBS) technology cannot distinguish IOPD from late-onset PD (LOPD) without clinical workup. Therefore, families of LOPD infants diagnosed by NBS may now spend years or even decades aware of their illness before symptoms appear, creating a pre-symptomatic awareness phase with which the medical community has little experience. The present study examines the effects of receiving a positive NBS result for PD on families. In-depth qualitative interviews were conducted with mothers of nine children (three IOPD and six LOPD) diagnosed via NBS, exploring their experiences, understanding of PD, how they are coping, and what impact diagnosis is having on family life. Interviews were coded using MaxQDA v.12 and analyzed for thematic trends. While overall opinion of NBS was favorable, it is clear many of the concerns anticipated by HCPs, patients, and families regarding NBS for late-onset LSDs are being realized to varying degrees; LOPD families are becoming patients-in-waiting. Increased fear/anxiety and living with uncertainty (regarding diagnosis, their children's future, and when to start treatment) were predominant themes, with all families voicing considerable emotional reactions and varied social and healthcare support concerns. Coping strategies and psychosocial challenges are interpreted using Rolland & Williams' Family Systems Genetic Illness model. Recommendations for improvement in delivery of service, as well as families' advice for future parents and HCPs, are discussed.

Receiver operating curve analyses of urinary titin of healthy 3-y-old children may be a noninvasive screening method for Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD) is a progressive, fatal muscle wasting disease. Early detection of DMD by mass screening may enable the early treatment of these patients. We have reported that urinary titin concentration, an indicator of severe muscle wasting, is a diagnostic biomarker for DMD.

METHODS

Urinary titin concentrations were measured in healthy 3-y-old children and, by comparison with concentrations in 4 DMD patients, and validated as a screening biomarker for DMD. Urine samples were obtained from 100 healthy Japanese children, 52 boys and 48 girls, and their urinary titin concentrations measured by ELISA.

RESULTS

The mean ± SD urinary titin concentration was 1.5 ± 2.5 nmol/l, and the mean urinary titin concentration normalized to creatinine was 2.2 ± 4.1 pmol/mg creatinine, with no differences between boys and girls. Histograms and box-and-whisker plots showed that almost all titin and normalized titin concentrations were in narrow ranges, with one outlier in common. Receiver operating characteristic curve analysis showed that titin and normalized-titin concentrations from healthy 3-y-olds were completely separate from those of 3-y-old DMD patients.

CONCLUSIONS

These findings indicate that urinary titin may be an excellent non-invasive biomarker to screen for DMD.

The phenotype, genotype, and outcome of infantile-onset Pompe disease in 18 Saudi patients

Infantile-Onset Pompe Disease (IOPD) is an autosomal recessive disorder of glycogen metabolism resulting from deficiency of the lysosomal hydrolase acid α-glucosidase encoded by GAA gene. Affected infants present before the age of 12 months with hypotonia, muscle weakness, and hypertrophic cardiomyopathy. Enzyme replacement therapy (ERT) has been shown to improve survival, cardiac mass, and motor skills. In this work, we aim to illustrate the genotypes of IOPD and the outcome of ERT in our population. The medical records of infants with confirmed diagnosis of IOPD who received ERT were reviewed. Eighteen infants (7 males, 11 females) were included in the study. The median age at presentation was 2 months and the median age at the start of ERT was 4.5 months. Fifteen (83.3%) infants died with a median age at death of 12 months. The 3 alive infants (whose current ages are 6½ years, 6 years, and 10 years), who were initiated on ERT at the age of 3 weeks, 5 months, and 8 months respectively, has had variable response with requirement of assisted ventilation in one child and tracheostomy in another child. All infants were homozygous for GAA mutations except one infant who was compound heterozygous. All infants (n = 8) with truncating mutations died. Our work provides insight into the correlation of genotypes and outcome of ERT in IOPD in Saudi Arabia. Our data suggest that early detection of cases, through newborn screening, and immunomodulation before the initiation of ERT may improve the outcome of ERT in Saudi infants with IOPD.