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1.
Clin Lab ; 70(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38747911

ABSTRACT

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.


Subject(s)
Genetic Testing , Muscular Atrophy, Spinal , Neonatal Screening , Humans , Infant, Newborn , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Pilot Projects , Genetic Testing/standards , Genetic Testing/methods , Neonatal Screening/standards , Neonatal Screening/methods , China , Dried Blood Spot Testing/standards , Dried Blood Spot Testing/methods , Quality Assurance, Health Care , Laboratories, Clinical/standards , Survival of Motor Neuron 1 Protein/genetics
2.
Pediatr Int ; 66(1): e15769, 2024.
Article in English | MEDLINE | ID: mdl-38742693

ABSTRACT

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.


Subject(s)
Echocardiography , Humans , Male , Female , Case-Control Studies , Child , Child, Preschool , Adolescent , Electrocardiography , Infant , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/physiopathology , Muscular Atrophy, Spinal/blood , Biomarkers/blood , Spinal Muscular Atrophies of Childhood/diagnosis , Spinal Muscular Atrophies of Childhood/physiopathology , Spinal Muscular Atrophies of Childhood/blood , Spinal Muscular Atrophies of Childhood/complications , Heart Function Tests/methods
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(6): 661-668, 2024 Jun 10.
Article in Chinese | MEDLINE | ID: mdl-38818549

ABSTRACT

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.


Subject(s)
Genetic Carrier Screening , Genetic Counseling , Muscular Atrophy, Spinal , Humans , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/diagnosis , Genetic Carrier Screening/methods , Genetic Testing/methods , Consensus , China
5.
Ann Clin Transl Neurol ; 11(5): 1090-1096, 2024 May.
Article in English | MEDLINE | ID: mdl-38600653

ABSTRACT

OBJECTIVES: Mandatory newborn screening (NBS) for spinal muscular atrophy (SMA) was implemented for the first time in Italy at the end of 2021, allowing the identification and treatment of patients at an asymptomatic stage. METHODS: DNA samples extracted from dried blood spot (DBS) from newborns in Apulia region were analysed for SMA screening by using a real-time PCR-based assay. Infants harbouring homozygous deletion of SMN1 exon 7 confirmed by diagnostic molecular tests underwent clinical and neurophysiological assessment and received a timely treatment. RESULTS: Over the first 20 months since regional NBS introduction, four out of 42,492 (0.009%) screened children were found to carry a homozygous deletion in the exon 7 of SMN1 gene, with an annual incidence of 1:10,623. No false negatives were present. Median age at diagnosis was 7 days and median age at treatment was 20.5 days. Three of them had two copies of SMN2 and received gene therapy, while the one with three SMN2 copies was treated with nusinersen. All but one were asymptomatic at birth, showed no clinical signs of disease after a maximum follow-up of 16 months and reached motor milestones appropriate with their age. The minimum interval between diagnosis and the treatment initiation was 9 days. INTERPRETATION: The timely administration of disease-modifying therapies prevented presymptomatic subjects to develop disease symptoms. Mandatory NBS for SMA should be implemented on a national scale.


Subject(s)
Muscular Atrophy, Spinal , Neonatal Screening , Survival of Motor Neuron 1 Protein , Humans , Italy , Infant, Newborn , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/therapy , Survival of Motor Neuron 1 Protein/genetics , Female , Male , Survival of Motor Neuron 2 Protein/genetics , Oligonucleotides/administration & dosage , Oligonucleotides/pharmacology , Infant
7.
JAMA Pediatr ; 178(6): 540-547, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38587854

ABSTRACT

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.


Subject(s)
Neonatal Screening , Humans , Neonatal Screening/methods , Infant, Newborn , Female , Male , Infant , Germany , Registries , Muscular Atrophy, Spinal/diagnosis , Pilot Projects , Early Diagnosis
8.
J Mol Diagn ; 26(5): 364-373, 2024 May.
Article in English | MEDLINE | ID: mdl-38490302

ABSTRACT

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder primarily caused by the deletion or mutation of the survival motor neuron 1 (SMN1) gene. This study assesses the diagnostic potential of long-read sequencing (LRS) in three patients with SMA. For Patient 1, who has a heterozygous SMN1 deletion, LRS unveiled a missense mutation in SMN1 exon 5. In Patient 2, an Alu/Alu-mediated rearrangement covering the SMN1 promoter and exon 1 was identified through a blend of multiplex ligation-dependent probe amplification, LRS, and PCR across the breakpoint. The third patient, born to a consanguineous family, bore four copies of hybrid SMN genes. LRS determined the genomic structures, indicating two distinct hybrids of SMN2 exon 7 and SMN1 exon 8. However, a discrepancy was found between the SMN1/SMN2 ratio interpretations by LRS (0:2) and multiplex ligation-dependent probe amplification (0:4), which suggested a limitation of LRS in SMA diagnosis. In conclusion, this newly adapted long PCR-based third-generation sequencing introduces an additional avenue for SMA diagnosis.


Subject(s)
Muscular Atrophy, Spinal , Humans , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Mutation , Motor Neurons , Exons/genetics , Heterozygote , Survival of Motor Neuron 1 Protein/genetics
9.
Neuromuscul Disord ; 37: 29-35, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38520993

ABSTRACT

5q-associated spinal muscular atrophy (SMA) is the most common autosomal recessive neurological disease. Depletion in functional SMN protein leads to dysfunction and irreversible degeneration of the motor neurons. Over 95 % of individuals with SMA have homozygous exon 7 deletions in the SMN1 gene. Most of the remaining 4-5 % are compound heterozygous for deletion and a disease-associated sequence variant in the non-deleted allele. Individuals with SMA due to bi-allelic SMN1 sequence variants have rarely been reported. Data regarding their clinical phenotype, disease progression, outcome and treatment response are sparse. This study describes six individuals from three families, all with homozygous sequence variants in SMN1, and four of whom received treatment with disease-modifying therapies. We also describe the challenges faced during the diagnostic process and intrafamilial phenotypic variability observed between siblings.


Subject(s)
Muscular Atrophy, Spinal , Child , Humans , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/diagnosis , Motor Neurons , Exons , Nerve Tissue Proteins/genetics , Phenotype , Survival of Motor Neuron 1 Protein/genetics
10.
Genes (Basel) ; 15(3)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38540372

ABSTRACT

In newborn screening (NBS), it is important to consider the availability of multiplex assays or other tests that can be integrated into existing systems when attempting to implement NBS for new target diseases. Recent developments in innovative testing technology have made it possible to simultaneously screen for severe primary immunodeficiency (PID) and spinal muscular atrophy (SMA) using quantitative real-time polymerase chain reaction (qPCR) assays. We describe our experience of optional NBS for severe PID and SMA in Osaka, Japan. A multiplex TaqMan qPCR assay was used for the optional NBS program. The assay was able to quantify the levels of T-cell receptor excision circles and kappa-deleting recombination excision circles, which is useful for severe combined immunodeficiency and B-cell deficiency screening, and can simultaneously detect the homozygous deletion of SMN1 exon 7, which is useful for NBS for SMA. In total, 105,419 newborns were eligible for the optional NBS program between 1 August 2020 and 31 August 2023. A case each of X-linked agammaglobulinemia and SMA were diagnosed through the optional NBS and treated at early stages (before symptoms appeared). Our results show how multiplex PCR-based NBS can benefit large-scale NBS implementation projects for new target diseases.


Subject(s)
Muscular Atrophy, Spinal , Neonatal Screening , Infant, Newborn , Humans , Neonatal Screening/methods , Real-Time Polymerase Chain Reaction/methods , Homozygote , Japan , Sequence Deletion , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics
11.
Sci Rep ; 14(1): 6634, 2024 03 19.
Article in English | MEDLINE | ID: mdl-38503830

ABSTRACT

Troponin T concentration (TNT) is commonly considered a marker of myocardial damage. However, elevated concentrations have been demonstrated in numerous neuromuscular disorders, pointing to the skeletal muscle as a possible extracardiac origin. The aim of this study was to determine disease-related changes of TNT in 5q-associated spinal muscular atrophy (SMA) and to screen for its biomarker potential in SMA. We therefore included 48 pediatric and 45 adult SMA patients in this retrospective cross-sequential observational study. Fluid muscle integrity and cardiac markers were analyzed in the serum of treatment-naïve patients and subsequently under disease-modifying therapies. We found a TNT elevation in 61% of SMA patients but no elevation of the cardiospecific isoform Troponin I (TNI). TNT elevation was more pronounced in children and particularly infants with aggressive phenotypes. In adults, TNT correlated to muscle destruction and decreased under therapy only in the subgroup with elevated TNT at baseline. In conclusion, TNT was elevated in a relevant proportion of patients with SMA with emphasis in infants and more aggressive phenotypes. Normal TNI levels support a likely extracardiac origin. Although its stand-alone biomarker potential seems to be limited, exploring TNT in SMA underlines the investigation of skeletal muscle integrity markers.


Subject(s)
Muscular Atrophy, Spinal , Troponin T , Adult , Humans , Child , Troponin T/genetics , Retrospective Studies , Troponin I , Muscular Atrophy, Spinal/diagnosis , Biomarkers
12.
Neuropediatrics ; 55(3): 171-177, 2024 06.
Article in English | MEDLINE | ID: mdl-38490253

ABSTRACT

BACKGROUND: The Pediatric Quality of Life Inventory™ (PedsQL™) Neuromuscular Module (PedsQL™ 3.0 NM) evaluates the health-related quality of life in children who are affected by neuromuscular diseases. This study's aim is to assess the adaptation of the PedsQL™ 3.0 NM Turkish version (PedsQL™ 3.0 NM-TR) for 2- to 4-year-olds in spinal muscular atrophy (SMA). METHODS: The procedure of translating the PedsQL™ 3.0 NM into Turkish was conducted in accordance with the translation methodology outlined by the PedsQL™ measurement model. The PedsQL™ 3.0 NM-TR was administered to 54 parents of children with SMA aged 2 to 4 years. The test-retest reliability and intraclass correlation coefficient (ICC) were measured for reliability analysis. Cronbach's α coefficient and item score correlations were calculated for internal consistency. Concurrent construct validity was evaluated by Pearson correlations between the outcomes of the PedsQL™ 4.0 Generic Core Scale (PedsQL™ 4.0 GCS) and the PedsQL™ 3.0 NM. RESULTS: The PedsQL™ 3.0 NM-TR total score shows excellent reliability. The Cronbach's α values for the PedsQL™ 3.0 NM ranged between 0.871 and 0.906, while those for the PedsQL™ 4.0 GCS ranged between 0.843 and 0.897. Test-retest ICC values for the PedsQL™ 3.0 NM-TR ranged between 0.812 and 0.917, and for the PedsQL™ 4.0 GCS ranged between 0.773 and 0.899. The relationship between the PedsQL™ 3.0 NM-TR and the subscores of the PedsQL™ 4.0 GCS demonstrated a range of correlations from excellent to fair, indicating the interplay between two scales. CONCLUSION: This study established the PedsQL™ 3.0 NM-TR as reliable, valid, and feasible for use in children aged 2 to 4 years with SMA.


Subject(s)
Muscular Atrophy, Spinal , Quality of Life , Humans , Child, Preschool , Reproducibility of Results , Female , Male , Turkey , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/physiopathology , Translations , Translating , Surveys and Questionnaires/standards , Psychometrics/standards , Psychometrics/instrumentation
13.
JAMA Pediatr ; 178(5): 500-502, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38436953

ABSTRACT

This case-control study uses computer vision and artificial intelligence to develop a screening tool for detecting spinal muscular atrophy in infants.


Subject(s)
Artificial Intelligence , Muscular Atrophy, Spinal , Humans , Muscular Atrophy, Spinal/diagnosis , Muscle Hypotonia/etiology , Muscle Hypotonia/diagnosis , Infant , Infant, Newborn , Male
14.
Genet Test Mol Biomarkers ; 28(5): 207-212, 2024 May.
Article in English | MEDLINE | ID: mdl-38533877

ABSTRACT

Background: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular life-threatening disorder. Owing to high carrier frequency, population-wide SMA screening to quantify the copy number of SMN gene is recommended by American College of Medical Genetics and Genomics. An accurate, reliable, short runaround time and cost-effective method may be helpful in mass population screening for SMA. Methods: Multiplex ligation-dependent probe amplification (MLPA) is a gold standard to estimate the copy number variation (CNV) for SMN1 and SMN2 genes. In this study, we validated droplet digital polymerase chain reaction (ddPCR) for the determination of CNV for both SMN1 and SMN2 exon 7 for a diagnostic purpose. In total, 66 clinical samples were tested using ddPCR, and results were compared with the MLPA as a reference test. Results: For all samples, CNV for SMN1 and SMN2 exon 7 was consentaneous between ddPCR and MLPA test results (κ = 1.000, p < 0.0001). In addition, ddPCR also showed a significant acceptable degree of test repeatability, coefficient of variation < 4%. Conclusion: ddPCR is expected to be utilitarian for CNV detection for carrier screening and diagnosis of SMA. ddPCR test results for CNV detection for SMN1/SMN2 exon 7 are concordant with the gold standard. ddPCR is a more cost-effective and time-saving diagnostic test for SMA than MLPA. Furthermore, it can be used for population-wide carrier screening for SMA.


Subject(s)
DNA Copy Number Variations , Exons , Genetic Carrier Screening , Multiplex Polymerase Chain Reaction , Muscular Atrophy, Spinal , Survival of Motor Neuron 1 Protein , Survival of Motor Neuron 2 Protein , Humans , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/diagnosis , Survival of Motor Neuron 1 Protein/genetics , Survival of Motor Neuron 2 Protein/genetics , DNA Copy Number Variations/genetics , Genetic Carrier Screening/methods , Multiplex Polymerase Chain Reaction/methods , Exons/genetics , Female , Male , Genetic Testing/methods , Heterozygote , Reproducibility of Results
15.
BMC Neurol ; 24(1): 93, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38468256

ABSTRACT

BACKGROUND: Spinal muscular atrophy (SMA) is a rare autosomal recessive hereditary neuromuscular disease caused by survival motor neuron 1 (SMN1) gene deletion or mutation. Homozygous deletions of exon 7 in SMN1 result in 95% of SMA cases, while the remaining 5% are caused by other pathogenic variants of SMN1. METHODS: We analyzed two SMA-suspected cases that were collected, with no SMN1 gene deletion and point mutation in whole-exome sequencing. Exon 1 deletion of the SMN gene was detected using Multiplex ligation-dependent probe amplification (MLPA) P021. We used long-range polymerase chain reaction (PCR) to isolate the SMN1 template, optimized-MLPA P021 for copy number variation (CNV) analysis within SMN1 only, and validated the findings via third-generation sequencing. RESULTS: Two unrelated families shared a genotype with one copy of exon 7 and a novel variant, g.70919941_70927324del, in isolated exon 1 of the SMN1 gene. Case F1-II.1 demonstrated no exon 1 but retained other exons, whereas F2-II.1 had an exon 1 deletion in a single SMN1 gene. The read coverage in the third-generation sequencing results of both F1-II.1 and F2-II.1 revealed a deletion of approximately 7.3 kb in the 5' region of SMN1. The first nucleotide in the sequence data aligned to the 7385 bp of NG_008691.1. CONCLUSION: Remarkably, two proband families demonstrated identical SMN1 exon 1 breakpoint sites, hinting at a potential novel mutation hotspot in Chinese SMA, expanding the variation spectrum of the SMN1 gene and corroborating the specificity of isolated exon 1 deletion in SMA pathogenesis. The optimized-MLPA P021 determined a novel variant (g.70919941_70927324del) in isolated exon 1 of the SMN1 gene based on long-range PCR, enabling efficient and affordable detection of SMN gene variations in patients with SMA, providing new insight into SMA diagnosis to SMN1 deficiency and an optimized workflow for single exon CNV testing of the SMN gene.


Subject(s)
Multiplex Polymerase Chain Reaction , Muscular Atrophy, Spinal , Humans , DNA Copy Number Variations/genetics , Workflow , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Motor Neurons , Exons/genetics , Survival of Motor Neuron 1 Protein/genetics
16.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(3): 294-299, 2024 Mar 10.
Article in Chinese | MEDLINE | ID: mdl-38448017

ABSTRACT

OBJECTIVE: To explore the clinical application of preimplantation genetic testing for monogenic disorders (PGT-M) in an unique case with Spinal muscular atrophy (SMA) type 2+0. METHODS: A special SMA family presented at the Third Affiliated Hospital of Guangzhou Medical University on October 19, 2020 was selected as the study subject. Multiple ligation-dependent probe amplification (MLPA) and molecular tagging linkage analysis were carried out to identify the SMN1 genotype of the couple and their fetus. Subsequently, next-generation sequencing (NGS), molecular tagging linkage analysis, and chromosomal microarray analysis were employed to determine the haplotypes and validate the result of PGT-M on the 11 embryos derived for the couple. RESULTS: The female partner was identified as a carrier of the rare SMN1[2+0] variant, and prenatal diagnosis confirmed the fetus to be affected by SMA. Ultimately, PGT-M has successfully selected four embryos free from the pathogenic SMN1 variants and X chromosome deletion. CONCLUSION: PGT-M can effectively prevent the transmission of rare genetic variants such as the SMA 2+0 subtype in the families. Above finding has provided guidance for genetic counseling and family planning for the couple.


Subject(s)
Genetic Testing , Muscular Atrophy, Spinal , Pregnancy , Female , Humans , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Genotype , Genetic Counseling , Haplotypes
17.
Continuum (Minneap Minn) ; 30(1): 119-132, 2024 02 01.
Article in English | MEDLINE | ID: mdl-38330475

ABSTRACT

OBJECTIVE: This article provides an overview of genetic myelopathies, a diverse group of inherited, degenerative conditions that may be broadly categorized as motor neuron disorders, disorders of spinocerebellar degeneration, leukodystrophies, and hereditary spastic paraplegia. Clinical examples from each category are provided to illustrate the spectrum of genetic myelopathies and their distinguishing features that aid in differentiating genetic myelopathies from potentially treatable acquired causes of myelopathy. LATEST DEVELOPMENTS: Advances in genetic testing have vastly enhanced current knowledge of genetic myelopathies and the ability to diagnose and provide appropriate counseling to patients and their families. However, potential health care disparities in access to genetic testing is a topic that must be further explored. Although treatment for most of these conditions is typically supportive, there have been recent therapeutic breakthroughs in treatments for amyotrophic lateral sclerosis, spinal muscular atrophy, and Friedreich ataxia. ESSENTIAL POINTS: Genetic myelopathies may present with chronic and progressive symptoms, a family history of similar symptoms, and involvement of other structures outside of the spinal cord. Imaging often shows spinal cord atrophy, but cord signal change is rare. Exclusion of reversible causes of myelopathy is a key step in the diagnosis. There are many different causes of genetic myelopathies, and in some cases, symptoms may overlap, which underscores the utility of genetic testing in confirming the precise underlying neurologic condition.


Subject(s)
Amyotrophic Lateral Sclerosis , Muscular Atrophy, Spinal , Spastic Paraplegia, Hereditary , Spinal Cord Diseases , Humans , Amyotrophic Lateral Sclerosis/diagnosis , Muscular Atrophy, Spinal/diagnosis , Spastic Paraplegia, Hereditary/diagnosis , Spinal Cord Diseases/diagnosis , Spinal Cord Diseases/genetics , Spinal Cord Diseases/therapy
18.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(2): 167-173, 2024 Feb 10.
Article in Chinese | MEDLINE | ID: mdl-38311554

ABSTRACT

OBJECTIVE: To explore the genetic etiology of two children with Spinal muscular atrophy with respiratory distress type 1 (SMARD1), and prevent the recurrence of birth defects. METHODS: Two unrelated families who had visited the Obstetrics and Gynecology Medical Center of Drum Tower Hospital from August to November 2021 were selected as the study subjects. Copy number of SMN1 gene exon 7 for the probands and their parents was detected by multiple ligation-dependent probe amplification (MLPA). and whole exome sequencing (WES) was carried out to screen the variants in the probands. Sanger sequencing was used to validate the variants within the families. Pathogenicity of the variants were predicted by bioinformatic analysis. Based on the results, prenatal diagnosis was performed for the fetuses. RESULTS: Both probands were found to harbor compound heterozygous variants of the IGHMBP2 gene, which were inherited from their parents. Among these, c.1144C>T, c.866delG and c.1666C>G were previously unreported and respectively classified as pathogenic variant (PVS1+PM2_Supporting+PP3+PP4), likely pathogenic variant (PM1+PM2_Supporting+PM4+PP3+PP4) and likely pathogenic variant (PM1+PM2_Supporting+PP2+PP3+PP4) based on the ACMG guidelines. Through preimplantation genetic testing for monogenic (PGT-M) and interventional prenatal diagnosis, transmission of the variants within the families was successfully blocked. CONCLUSION: The SMARD1 in both children may be attributed to the compound heterozygous variants of the IGHMBP2 gene, which has facilitated the genetic diagnosis and counselling, and provided reference for delineating the molecular pathogenesis of this disease.


Subject(s)
Muscular Atrophy, Spinal , Respiratory Distress Syndrome, Newborn , Pregnancy , Child , Female , Humans , Pedigree , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Prenatal Diagnosis , China , Mutation , DNA-Binding Proteins/genetics , Transcription Factors/genetics
19.
J Neurol ; 271(5): 2787-2797, 2024 May.
Article in English | MEDLINE | ID: mdl-38409538

ABSTRACT

Newborn screening for 5qSMA offers the potential for early, ideally pre-symptomatic, therapeutic intervention. However, limited data exist on the outcomes of individuals with 4 copies of SMN2, and there is no consensus within the SMA treatment community regarding early treatment initiation in this subgroup. To provide evidence-based insights into disease progression, we performed a retrospective analysis of 268 patients with 4 copies of SMN2 from the SMArtCARE registry in Germany, Austria and Switzerland. Inclusion criteria required comprehensive baseline data and diagnosis outside of newborn screening. Only data prior to initiation of disease-modifying treatment were included. The median age at disease onset was 3.0 years, with a mean of 6.4 years. Significantly, 55% of patients experienced symptoms before the age of 36 months. 3% never learned to sit unaided, a further 13% never gained the ability to walk independently and 33% of ambulatory patients lost this ability during the course of the disease. 43% developed scoliosis, 6.3% required non-invasive ventilation and 1.1% required tube feeding. In conclusion, our study, in line with previous observations, highlights the substantial phenotypic heterogeneity in SMA. Importantly, this study provides novel insights: the median age of disease onset in patients with 4 SMN2 copies typically occurs before school age, and in half of the patients even before the age of three years. These findings support a proactive approach, particularly early treatment initiation, in this subset of SMA patients diagnosed pre-symptomatically. However, it is important to recognize that the register will not include asymptomatic individuals.


Subject(s)
Muscular Atrophy, Spinal , Survival of Motor Neuron 2 Protein , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Age of Onset , Austria/epidemiology , Disease Progression , Germany , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/diagnosis , Neonatal Screening , Registries , Retrospective Studies , Survival of Motor Neuron 2 Protein/genetics , Switzerland
20.
Arq Neuropsiquiatr ; 82(1): 1-18, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38316428

ABSTRACT

Spinal muscular atrophy linked to chromosome 5 (SMA-5q) is an autosomal recessive genetic disease caused by mutations in the SMN1. SMA-5q is characterized by progressive degeneration of the spinal cord and bulbar motor neurons, causing severe motor and respiratory impairment with reduced survival, especially in its more severe clinical forms. In recent years, highly effective disease-modifying therapies have emerged, either acting by regulating the splicing of exon 7 of the SMN2 gene or adding a copy of the SMN1 gene through gene therapy, providing a drastic change in the natural history of the disease. In this way, developing therapeutic guides and expert consensus becomes essential to direct the use of these therapies in clinical practice. This consensus, prepared by Brazilian experts, aimed to review the main available disease-modifying therapies, critically analyze the results of clinical studies, and provide recommendations for their use in clinical practice for patients with SMA-5q. This consensus also addresses aspects related to diagnosis, genetic counseling, and follow-up of patients under drug treatment. Thus, this consensus provides valuable information regarding the current management of SMA-5q, helping therapeutic decisions in clinical practice and promoting additional gains in outcomes.


Atrofia muscular espinhal ligada ao cromossomo 5 (AME-5q) é uma doença genética de herança autossômica recessiva causada por mutações no gene SMN1. A AME-5q cursa com degeneração progressiva dos motoneurônios medulares e bulbares, acarretando grave comprometimento motor e respiratório com redução da sobrevida, especialmente nas suas formas clínicas mais graves. Nos últimos anos, terapias modificadoras da doença altamente eficazes, ou que atuam regulando o splicing do exon 7 do gene SMN2 ou adicionando uma cópia do gene SMN1 via terapia gênica, têm surgido, proporcionando uma mudança drástica na história natural da doença. Dessa forma, o desenvolvimento de guias terapêuticos e de consensos de especialistas torna-se importante no sentido de direcionar o uso dessas terapias na prática clínica. Este consenso, preparado por especialistas brasileiros, teve como objetivos revisar as principais terapias modificadoras de doença disponíveis, analisar criticamente os resultados dos estudos clínicos dessas terapias e prover recomendações para seu uso na prática clínica para pacientes com AME-5q. Aspectos relativos ao diagnóstico, aconselhamento genético e seguimento dos pacientes em uso das terapias também são abordados nesse consenso. Assim, esse consenso promove valiosas informações a respeito do manejo atual da AME-5q auxiliando decisões terapêuticas na prática clínica e promovendo ganhos adicionais nos desfechos finais.


Subject(s)
Muscular Atrophy, Spinal , Neurology , Humans , Genetic Counseling , Brazil , Consensus , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/therapy
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