Machine learning-enhanced electrical impedance myography to diagnose and track spinal muscular atrophy progression.

Objective.To evaluate electrical impedance myography (EIM) in conjunction with machine learning (ML) to detect infantile spinal muscular atrophy (SMA) and disease progression.Approach. Twenty-six infants with SMA and twenty-seven healthy infants had been enrolled and assessed with EIM as part of the NeuroNEXT SMA biomarker study. We applied a variety of modern, supervised ML approaches to this data, first seeking to differentiate healthy from SMA muscle, and then, using the best method, to track SMA progression.Main Results.Several of the ML algorithms worked well, but linear discriminant analysis (LDA) achieved 88.6% accuracy on subject muscles studied. This contrasts with a maximum of 60% accuracy that could be achieved using the single or multifrequency assessment approaches available at the time. LDA scores were also able to track progression effectively, although a multifrequency reactance-based measure also performed very well in this context.Significance.EIM enhanced with ML promises to be effective for providing effective diagnosis and tracking children and adults with SMA treated with currently available therapies. The normative trends identified here may also inform future applications of the technology in very young children. The basic analyses applied here could also likely be applied to other neuromuscular disorders characterized by muscle atrophy.

Health information literacy among children with spinal muscular atrophy and their caregivers.

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease that leads to multiple organ dysfunction. The advent of disease-modifying treatments makes the early diagnosis of SMA critical. Health information literacy is vital for obtaining, understanding, screening, and using health information. Considering the importance of early diagnosis and the challenges in obtaining accurate information on patients with SMA, this cross-sectional study assessed health information literacy among children with SMA and their caregivers in China. METHODS: Interviews with the caregivers of 10 patients with SMA were conducted by neurologists specializing in SMA. A questionnaire for evaluating the level of health information literacy was further developed among 145 children with SMA aged 10.0-120.0 months, with the average age of 81.9 months, and their caregivers. Parameters, such as the age at the onset of the first symptom and time from recognition of the first symptom to diagnosis, were examined. Health information literacy was measured using four dimensions: cognition, search, evaluation, and application. RESULTS: The average time from the first symptom to first medical consultation was 4.8 months, and that from the first symptom to diagnosis was 10.8 months. There is a significant delay from the onset of the initial symptoms to a definitive diagnosis. Thirty-five (24%) patients had poor while 26 (18%) had high health information literacy. The overall score for health information literacy was 69; the scores for health information cognition and application were 90 and 84, respectively. The scores for evaluation (61) and search (57) were low. Medical personnel were considered the most professional and credible sources of information. Additionally, search engines and patient organizations were the other two most important sources of health literacy. CONCLUSION: Patients with SMA and their caregivers had low levels of health information literacy. SMA information visibility and standardization need to be improved. Medical personnel with experience in the diagnosis and treatment of SMA and media should aim to share knowledge and increase the quality of life of those with SMA.

Camptocormia in a young man with anti-GAD-seropositive stiff-person syndrome.

Stiff-person syndrome (SPS) usually manifests as an autoimmune neuromuscular disorder characterised by pronounced and advancing rigidity, primarily affecting the trunk and proximal muscles. There are various clinical subtypes like classic SPS (truncal stiffness, generalised rigidity and muscle spasms), partial SPS (stiff-limb syndrome) and uncommon forms including progressive encephalomyelitis with rigidity and myoclonus. Camptocormia, defined as forward flexion of the spine in the upright position that disappears in the supine position, without fixed deformity, has been described only in two cases as an initial presentation of Anti glutamic acid decarboxylase (GAD) autoimmunity. We encountered a young male presenting with a progressive forward-leaning posture and involuntary rhythmic movements in the lower limb. Diagnostic workup included MRI, blood routines, autoimmune screening, genetic testing, lumbar puncture and electromyography. Elevated serum anti-GAD antibody levels, inflammatory CSF and certain other clinical features supported the diagnosis of SPS. Treatment involved benzodiazepines, muscle relaxants and immunotherapy with intravenous immunoglobulin. This case underscores the importance of considering immune-mediated causes, such as SPS, in patients presenting with camptocormia.

A rapid and easy-to-use spinal muscular atrophy screening tool based on primers with high specificity and amplification efficiency for SMN1 combined with single-stranded tag hybridization assay.

Spinal muscular atrophy (SMA) is an intractable neuromuscular disorder primarily caused by homozygous deletions in exon 7 of the SMN1 gene. Early diagnosis and prompt treatment of patients with SMA have a significant impact on prognosis, and several therapies have recently been developed. Current SMA screening tests require a significant turnaround time to identify patients with suspected SMA, due both to the interval between the birth of a newborn and the collection of blood for newborn mass screening and the difficulty in distinguishing between SMN1 and SMN2, a paralog gene that requires testing in specialized laboratories. The aim of this study was therefore to develop a novel SMA screening assay that can be rapidly performed in ordinary hospitals and clinics to overcome these issues. We designed over 100 combinations of forward and reverse primers with 3' ends targeting SMN1-specific sites around exon 7, and evaluated their specificity and amplification efficiency by quantitative PCR to identify the best primer pair. Furthermore, we performed a single-stranded tag hybridization assay after PCR. To evaluate the accuracy and practicality of the newly developed assay, we analyzed saliva specimens from five patients with SMA and two SMA carriers collected in an outpatient clinic and DNA specimens from three patients with SMA and four SMA carriers from a biobank, together with those from healthy individuals. DNA and raw saliva specimens from all patients with SMA demonstrated a biallelic loss of SMN1, whereas those from carriers and healthy individuals did not. The results of 50 independent experiments were consistent for all samples. The assay could be completed within one hour. This simple and convenient new screening tool has the potential to allow patients with SMA to receive disease-modifying therapies within a shorter timeframe.

Emphasis on the importance of comprehensive clinical and genetic analysis - spinal muscular atrophy combined with phenylketonuria: A case report.

RATIONALE: Both spinal muscular atrophy (SMA) and Phenylketonuria (PKU) are caused by biallelic pathogenic mutations. However, there has been no report on case who suffering from both diseases simultaneously. SMA mainly affects the motor function while PKU may have an impact on both the intelligence and motor function. But if only 1 disease is treated while neglecting the other, the treatment effect will be compromised. Here, for the first time, we report a case from China diagnosed with both these diseases and treated properly. PATIENT CONCERNS: A boy was admitted to the Children's Hospital Affiliated to Shandong University (Jinan, China) due to "limb weakness for 19 months" when he was 22 months old. Considering that the child's motor function development is delayed, we made a comprehensive examinations including inherited metabolic diseases and found a significantly increase of phenylalanine concentration in the blood which indicating PKU. Combined with his typical clinical manifestations of SMA, target capture sequencing followed by Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) technologies were used for genetic confirmation. DIAGNOSES: SMA and PKU was confirmed. INTERVENTIONS: The child was treated with risdiplam and low phenylalanine formula immediately when he was diagnosed with both SMA and PKU. OUTCOMES: The child showed remarkable improvement in motor function and significant decrease of blood phenylalanine concentration after treatment. LESSONS: To our knowledge, this is the first reported case of SMA combined with PKU. This case expands our understanding of diagnosis for synchronous SMA and PKU and highlights the importance of comprehensive examinations and the utilizing of various genetic testing methods to make an accurate diagnosis of genetic diseases, which may help avoiding the progressive damage caused by certain genetic disease with insidious clinical symptoms.

Newborn Screening and Birth Prevalence for Spinal Muscular Atrophy in the US.

This cross-sectional study describes the collection and use of state-provided data on newborn screening for spinal muscular atrophy.

Rare Variants of the SMN1 Gene Detected during Neonatal Screening.

During the expanded neonatal screening program conducted in 2023, we analyzed samples obtained from 1,227,130 out of 1,256,187 newborns in the Russian Federation in order to detect 5q spinal muscular atrophy (5q SMA). Within the 253-sample risk group formed based on the results of the first screening stage, 5 samples showed a discrepancy between the examination results obtained via various screening methods and quantitative MLPA (used as reference). The discrepancy between the results was caused by the presence of either a c.835-18C>T intronic variant or a c.842G>C p.(Arg281Thr) missense variant in the SMN1 gene, both of which are located in the region complementary to the sequences of annealing probes for ligation and real-time PCR. Three newborns had the c.835-18C>T variant in a compound heterozygous state with a deletion of exons 7-8 of the SMN1 gene, one newborn with two copies of the SMN1 gene had the same variant in a heterozygous state, and one newborn had both variants-c.835-18C>T and c.842G>C p.(Arg281Thr)-in a compound heterozygous state. Additional examination was carried out for these variants, involving segregation analysis in families, carriage analysis in population cohorts, and RNA analysis. Based on the obtained results, according to the ACMG criteria, the c.835-18C>T intronic variant should be classified as likely benign, and the c.842G>C p.(Arg281Thr) missense substitution as a variant of uncertain clinical significance. All five probands are under dynamic monitoring. No 5q SMA symptoms were detected in these newborns neonatally or during a 1-year follow-up period.

Communicating the diagnosis of spinal muscular atrophy in endogamous vs. non-endogamous regions.

INTRODUCTION: The high prevalence of endogamy, or inbreeding, in northeastern Brazil, is due to historical and cultural factors, with large families living in cities far from the coast and subject to low socioeconomic and infrastructure levels. This breeding practice results in low genetic variability with an increased prevalence of rare autosomal recessive and neurodegenerative diseases, such as spinal muscular atrophy (SMA). OBJECTIVE: Understanding the impact of communicating the diagnosis of SMA on the mental health of patients and their families and the differences between the Northeast (endogamous region) and the other regions of Brazil (non-endogamous ones). METHODS: Cross-sectional study obtained through a structured questionnaire about the moment of receiving the SMA diagnosis, containing the Impact of Event Scale-Revised. RESULTS AND DISCUSSION: The sample consisted of 100 volunteers from all regions of Brazil, 47 patients diagnosed with SMA and 53 family members present at the time of the diagnosis. There was a predominance of females (83%) and homogeneity between the groups for the variables gender, age, color, education, religion, and SMA subtype (1, 2, 3, and 4). The Northeast region, representing 43% of the sample, despite being less economically favored, showed greater satisfaction with medical care and inclusion in health services, with less self-reported psychological trauma and fewer signs of post-traumatic stress disorder (PTSD) related to the moment of receiving the diagnosis. The non-endogamous regions, in turn, reported the presence of strong waves of emotion, sleep problems, feelings of irritability, anger, and the presence of bad thoughts related to this situation. CONCLUSION: The feeling of inclusion in health services and satisfaction with medical care in the endogamous region had a positive impact on the mental health of those involved, reducing psychological trauma and signs of PTSD arising from the communication of the SMA diagnosis.

Integrated Approaches and Practical Recommendations in Patient Care Identified with 5q Spinal Muscular Atrophy through Newborn Screening.

In recent years, significant progress has been made in 5q Spinal Muscular Atrophy therapeutics, emphasizing the importance of early diagnosis and intervention for better clinical outcomes. Characterized by spinal cord motor neuron degeneration, 5q-SMA leads to muscle weakness, swallowing difficulties, respiratory insufficiency, and skeletal deformities. Recognizing the pre-symptomatic phases supported by screening and confirmatory genetic tests is crucial for early diagnosis. This work addresses key considerations in implementing 5q-SMA screening within the Brazilian National Newborn Screening Program and explores Brazil's unique challenges and opportunities, including genetic tests, time-to-patient referral to specialized centers, program follow-up, and treatment algorithms. We aim to guide healthcare professionals and policymakers, facilitating global discussions, including Latin American countries, and knowledge-sharing on this critical subject to improve the care for newborns identified with 5q SMA.

Brazilian version of the Hammersmith Functional Motor Scale Expanded: cross-cultural adaptation and validation.

BACKGROUND: The Hammersmith Functional Motor Scale Expanded (HFMSE) has been widely used to assess the motor function of patients with spinal muscular atrophy (SMA) older than 2 years, with the ability to sit and/or walk. OBJECTIVE: To translate, cross-culturally adapt and validate the HFMSE to Brazilian Portuguese. METHODS: The translation process and cross-cultural adaptation followed international guidelines recommendations. The reliability and applicability of the Brazilian version consisted of the application of the HFMSE (in Brazilian Portuguese) to 20 patients with types 2 and 3 SMA. Two examiners assessed the participants for interrater reliability, through the analysis of Kappa reliability agreement (k) and intraclass correlation coefficient (ICC). RESULTS: The HFMSE was successfully translated and cross culturally adapted to Brazilian Portuguese. Twenty participants with types 2 and 3 SMA were enrolled in the study (type 2 = 6; type 3 = 14). The ICC for the total score showed very high reliability (ICC =1.00), and the reliability of each of the items individually was considered excellent (Kappa > 0.80). CONCLUSION: The Brazilian version of the HFMSE proved to be valid and reliable for the evaluation of SMA patients older than 2 years with the ability to sit and/or walk.

ANTECEDENTES: A Hammersmith Functional Motor Scale Expanded (HFMSE) tem sido amplamente utilizada para avaliar a função motora de pacientes com atrofia muscular espinhal (AME) maiores de dois anos, com capacidade de sentar e/ou andar. OBJETIVO: Traduzir, adaptar transculturalmente e validar a HFMSE para o português brasileiro. MéTODOS: A tradução e a adaptação transcultural seguiram as diretrizes internacionais. A confiabilidade e a aplicabilidade da versão brasileira consistiram na aplicação da HFMSE (em português brasileiro) em 20 pacientes com AME tipos 2 e 3. Dois examinadores avaliaram os participantes quanto à confiabilidade interexaminadores, por meio da análise da concordância de confiabilidade Kappa (k) e do coeficiente de correlação intraclasse (intraclass correlation coefficient [ICC]). RESULTADOS: O processo de tradução e adaptação transcultural da HFMSE para o português brasileiro foi concluído com sucesso. Vinte participantes com AME tipos 2 e 3 foram incluídos no estudo (tipo 2 = 6; tipo 3 = 14). O ICC para o escore total apresentou confiabilidade alta (ICC = 1.00) e a confiabilidade de cada um dos itens individualmente foi considerada excelente (K > 0,80). CONCLUSãO: A HFMSE (PT-BR) mostrou-se válida e confiável para a avaliação de pacientes com AME, com mais de dois anos de idade e com capacidade de sentar-se independentemente e/ou andar.

Quality considerations and major pitfalls for high throughput DNA-based newborn screening for severe combined immunodeficiency and spinal muscular atrophy.

BACKGROUND: Many newborn screening programs worldwide have introduced screening for diseases using DNA extracted from dried blood spots (DBS). In Germany, DNA-based assays are currently used to screen for severe combined immunodeficiency (SCID), spinal muscular atrophy (SMA), and sickle cell disease (SCD). METHODS: This study analysed the impact of pre-analytic DNA carry-over in sample preparation on the outcome of DNA-based newborn screening for SCID and SMA and compared the efficacy of rapid extraction versus automated protocols. Additionally, the distribution of T cell receptor excision circles (TREC) on DBS cards, commonly used for routine newborn screening, was determined. RESULTS: Contaminations from the punching procedure were detected in the SCID and SMA assays in all experimental setups tested. However, a careful evaluation of a cut-off allowed for a clear separation of true positive polymerase chain reaction (PCR) amplifications. Our rapid in-house extraction protocol produced similar amounts compared to automated commercial systems. Therefore, it can be used for reliable DNA-based screening. Additionally, the amount of extracted DNA significantly differs depending on the location of punching within a DBS. CONCLUSIONS: Newborn screening for SMA and SCID can be performed reliably. It is crucial to ensure that affected newborns are not overlooked. Therefore a carefully consideration of potential contaminating factors and the definition of appropriate cut-offs to minimise the risk of false results are of special concern. It is also important to note that the location of punching plays a pivotal role, and therefore an exact quantification of TREC numbers per µl may not be reliable and should therefore be avoided.

[Experience with the use of risdiplam in a familial case of spinal muscular atrophy 5q in patients with a homozygous deletion of the SMN1 gene and the same copy number of the SMN2 gene]. / Opyt primeneniya risdiplama pri semeinom sluchae spinal'noi myshechnoi atrofii 5q u patsientov s gomozigotnoi deletsiei gena SMN1 i odinakovym kolichestvom kopii gena SMN2.

Advances in the treatment of spinal muscular atrophy (SMA) have revolutionized the field. SMA is a rare autosomal recessive neurodegenerative motor neuron disease in which wide phenotypic variability has been described. The rate of increase in neurological deficit and the severity of the disease is mainly determined by the amount of functional SMN (Survival of Motor Neuron) protein. However, the clinical picture may differ significantly in patients carrying homozygous deletions of the SMN1 gene (Survival of Motor Neuron 1) and an identical number of copies of the SMN2 gene (Survival of Motor Neuron 2). A family clinical case of adult patients with spinal muscular atrophy 5q with a homozygous deletion of the SMN1 gene and the same number of copies of the SMN2 gene, having a different clinical picture of the disease, is presented, and the dynamics of the condition against the background of oral pathogenetic therapy is presented.

Cardiac function evaluation in children with spinal muscular atrophy: A case-control study.

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disorder characterized by degeneration of lower motor neurons, resulting in progressive muscle weakness and atrophy. However, little is known regarding the cardiac function of children with SMA. METHODS: We recruited SMA patients younger than 18 years of age from January 1, 2022, to April 1, 2022, in the First Affiliated Hospital of Sun Yat-sen University. All patients underwent a comprehensive cardiac evaluation before treatment, including history taking, physical examination, blood tests of cardiac biomarkers, assessment of echocardiography and electrocardiogram. Age/gender-matched healthy volunteers were recruited as controls. RESULTS: A total of 36 SMA patients (26 with SMA type 2 and 10 with SMA type 3) and 40 controls were enrolled in the study. No patient was clinically diagnosed with heart failure. Blood tests showed elevated values of creatine kinase isoenzyme M and isoenzyme B (CK-MB) mass and high-sensitivity cardiac troponin T (hs-cTnT) in spinal muscular atrophy (SMA) patients. Regarding echocardiographic parameters, SMA children were detected with lower global left and right ventricular longitudinal strain, abnormal diastolic filling velocities of trans-mitral and trans-tricuspid flow. The results revealed no clinical heart dysfunction in SMA patients, but subclinical ventricular dysfunction was seen in SMA children including the diastolic function and myocardial performance. Some patients presented with elevated heart rate and abnormal echogenicity of aortic valve or wall. Among these SMA patients, seven patients (19.4%) had scoliosis. The Cobb's angles showed a significant negative correlation with LVEDd/BSA, but no correlation with other parameters, suggesting that mild scoliosis did not lead to significant cardiac dysfunction. CONCLUSIONS: Our findings warrant increased attention to the cardiac status and highlight the need to investigate cardiac interventions in SMA children.

Results of a Pilot External Quality Assessment Scheme for Genetic Testing of Newborns with Spinal Muscular Atrophy.

BACKGROUND: This study aims to evaluate the ability of laboratories to perform spinal muscular atrophy (SMA) genetic testing in newborns based on dried blood spot (DBS) samples, and to provide reference data and advance preparation for establishing the pilot external quality assessment (EQA) scheme for SMA genetic testing of newborns in China. METHODS: The pilot EQA scheme contents and evaluation principles of this project were designed by National Center for Clinical Laboratories (NCCL), National Health Commission. Two surveys were carried out in 2022, and 5 batches of blood spots were submitted to the participating laboratory each time. All participating laboratories conducted testing upon receiving samples, and test results were submitted to NCCL within the specified date. RESULTS: The return rates were 75.0% (21/28) and 95.2% (20/21) in the first and second surveys, respectively. The total return rate of the two examinations was 83.7% (41/49). Nineteen laboratories (19/21, 90.5%) had a full score passing on the first survey, while in the second survey twenty laboratories (20/20, 100%) scored full. CONCLUSIONS: This pilot EQA survey provides a preliminary understanding of the capability of SMA genetic testing for newborns across laboratories in China. A few laboratories had technical or operational problems in testing. It is, therefore, of importance to strengthen laboratory management and to improve testing capacity for the establishment of a national EQA scheme for newborn SMA genetic testing.

[Expert consensus over genetic counseling for carrier screening of Spinal muscular atrophy].

Spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disease with a carrier frequency of 1/60 ~ 1/40, is characterized by severe clinical symptoms, high mortality rate, and expensive treatment costs. Carrier screening is of paramount importance to detect high-risk couples, and therefore to reduce the occurrence of SMA. In China, SMA carrier screening has become widespread, though there is still a lack of genetic counseling expertise. This article has focused on the current challenges for SMA carrier screening, including the screening methods, target population, screening procedures, and pre-/post-testing counseling. The aim is to standardize its application and counseling in the clinical practice.