SMA Patients Research Articles

Challenges Faced By Families of SMA Patients

SMA, a genetic neuromuscular disease that affects the control of muscle movement and results in severe motor disorders, is among the rare diseases. Due to the low prevalence of rare diseases and serious problems with correct diagnosis, there may be delays in diagnosis. When the studies on SMA are examined, it is known that the issues related to diagnosis are mostly emphasised, but a limited number of studies have been conducted on the current issues of patients with SMA or their caregivers. In addition to studies on treatment, it would be useful to consider the patient and his/her environment together in studies on the quality of life of patients and caregivers. Examining the concept of quality of life in SMA disease will form the basis for studies on quality of life, and at the same time, the continuity of studies on the subject will be ensured. In this sense, current issues the treatment of patients diagnosed with SMA was addressed in this study. The fact that these patients experience significant deficiencies such as respiratory impairment, malnutrition and skeletal deformity causes them to face difficulties in meeting their basic needs, especially in nutrition and toileting. These problems reduce the quality of life of patients and their relatives. Therefore, early diagnosis and providing medical, psychological, and social support to patients and their relatives will be effective in their quality of life. In this review, recommendations were made to address the current issues of SMA patients and their relatives.

Paradoxical metabolic acidosis after vomiting in children with spinal muscular atrophy: A report of 9 patients

BackgroundSpinal muscular atrophy (SMA) is a hereditary neuromuscular disease that progresses toward restrictive respiratory failure due to muscle paralysis. We observed that SMA patients presented with a specific clinical and laboratory profile, consisting of severe metabolic acidosis following an episode of mild vomiting. This is an unusual, little-known, and life-threatening situation for these patients, as hyperventilation induced by metabolic acidosis can lead to exhaustion and to death by mixed acidosis. ObjectiveThe aim of our study was to describe this paradoxical acidosis after vomiting in SMA patients and to discuss the physiological basis of this condition. MethodsWe conducted a retrospective single-center study reviewing the clinical and laboratory data of SMA patients who were hospitalized in the intensive care unit for severe metabolic acidosis after vomiting. ResultsOur cohort comprised 11 cases. On arrival, the median pH of the patients was 7.23 with a median bicarbonate concentration of 11.7 mmol/L and almost half of them (45 %) had ketone bodies in the blood and/or urine. The median correction time was 24 h for pH and 48 h for bicarbonate concentrations after receiving intravenous hydration with a glucose solution. ConclusionsWe suggest that SMA patients are particularly sensitive to ketoacidosis induced by fasting, even after a few episodes of mild vomiting. Moreover, they have a low buffering capacity due to their severe amyotrophy, which favors metabolic acidosis. They must be quickly hydrated through a glucose-containing solution to avoid exhaustion, mixed acidosis, and death.

190P Spectrum of phenotypes in SMA patients with four SMN2 copies in France (Registre SMA France)

190P Spectrum of phenotypes in SMA patients with four SMN2 copies in France (Registre SMA France)

146P Investigation of bone health in a large cohort of naïve SMA patients

146P Investigation of bone health in a large cohort of naïve SMA patients

153P Long-term effectiveness of risdiplam in non-ambulant SMA patients with prolonged disease duration

153P Long-term effectiveness of risdiplam in non-ambulant SMA patients with prolonged disease duration

203P Towards a better analysis of SMN2 structures and variants by complete sequencing of the SMN locus in an international cohort of 564 SMA patients

203P Towards a better analysis of SMN2 structures and variants by complete sequencing of the SMN locus in an international cohort of 564 SMA patients

189P Diagnostic journey of SMA patients in a reference center in Brazil

189P Diagnostic journey of SMA patients in a reference center in Brazil

183P CuidAME: The Spanish longitudinal Registry of SMA patients. A global view in 2024

183P CuidAME: The Spanish longitudinal Registry of SMA patients. A global view in 2024

196P Profiling neuroinflammatory markers in CSF from paediatric SMA patients in response to nusinersen treatment

196P Profiling neuroinflammatory markers in CSF from paediatric SMA patients in response to nusinersen treatment

Prognostic factors for tube feeding in type I SMA patients treated with disease-modifying therapies: a cohort study

The aim of this study was to assess the need for tube feeding in a cohort of treated infants with type I SMA and to identify predictive factors. All patients were classified at baseline, when treatment started, and at follow-up according to their functional level and the need for tube feeding. Fisher’s exact test was used to examine the associations between the outcome at the last follow-up and SMA type, SMN2 copy number, and baseline nutritional status. ANOVA was performed to compare CHOP INTEND scores and age at treatment initiation with outcomes. The cohort includes 75 type I SMA infants treated between 0.1 and 5 years of age. At the last follow-up, 34 had no need for tube feeding, 9 had tube feeding but were also able to be fed by mouth, and 32 had tube feeding and were unable to be fed by mouth. Thirty of the 41 infants with tube feeding at follow-up already had feeding difficulties when treatment was started. The need for tube feeding at follow-up was associated with the level of feeding involvement at baseline and with CHOP INTEND scores [p < 0.001] but not with SMN2 copy number, SMA type 1 subtypes or age at treatment. The results of this study suggest that the need for tube feeding is not frequent in treated infants with type I SMA and, when occurring, can be predicted by the level of feeding involvement and low CHOP INTEND scores at baseline.What is Known:• The advent of disease-modifying therapies is increasingly changing the approach to swallowing and nutritional management in type I SMA.• Clinical trials and real-world data using all three disease-modifying therapies report a rather wide variability of feeding outcome and need for tube feeding that is often related to different cohorts that makes comparison between studies very difficult.What is New:• The real-world findings of this study, including all the children treated since treatments became available, confirmed that the need for tube feeding is not an invariable finding.• The level of feeding involvement at baseline appears to be a reliable prognostic indicator of bulbar outcome.• The results highlight the need for interventional studies with structured Speech and Language Therapist protocols that will help to better understand the extent to which bulbar function can be maintained or regained even in children requiring tube feeding.

Dysregulation of cerebrospinal fluid metabolism profiles in spinal muscular atrophy patients: a case control study

BackgroundSpinal muscular atrophy (SMA) is a neurodegenerative disorder. Although prior studies have investigated the metabolomes of SMA in various contexts, there is a gap in research on cerebrospinal fluid (CSF) metabolomics compared to healthy controls. CSF metabolomics can provide insights into central nervous system function and patient outcomes. This study aims to investigate CSF metabolite profiles in untreated SMA patients to enhance our understanding of SMA metabolic dysregulation.MethodsThis case control study included 15 SMA patients and 14 control subjects. CSF samples were collected, and untargeted metabolomics was conducted to detect metabolites in SMA and control groups.ResultsA total of 118 metabolites abundance were significantly changed between the SMA and control groups. Of those, 27 metabolites with variable importance for the projection (VIP) ≥ 1.5 were identified. The top 5 differential metabolites were N-acetylneuraminic acid (VIP = 2.38, Fold change = 0.43, P = 5.49 × 10–5), 2,3-dihydroxyindole (VIP = 2.33, Fold change = 0.39, P = 1.81 × 10–4), lumichrome (VIP = 2.30, Fold change = 0.48, P = 7.90 × 10–5), arachidic acid (VIP = 2.23, Fold change = 10.79, P = 6.50 × 10–6), and 10-hydroxydecanoic acid (VIP = 2.23, Fold change = 0.60, P = 1.44 × 10–4). Cluster analysis demonstrated that the differentially metabolites predominantly clustered within two main categories: protein and amino acid metabolism, and lipid metabolism.ConclusionsThe findings highlight the complexity of SMA, with widespread effects on multiple metabolic pathways, particularly in amino acid and lipid metabolism. N-acetylneuraminic acid may be a potential treatment for functional improvement in SMA. The exact mechanisms and potential therapeutic targets associated with metabolic dysregulation in SMA require further investigation.

The prevalence of SMN gene deletion/duplication in spinal muscular atrophy families referred to neuro-genetic centers of Mashhad, Iran

BackgroundSpinal muscular atrophy (SMA) is a group of motor neuron diseases. In 95% of SMA patients, the telomeric copy of the SMN gene (SMN1) is homozygously deleted. Due to the autosomal recessive pattern of SMA inheritance, individuals with a family history of SMA are at risk of being carriers. A total of 622 individuals from SMA families, including parents, siblings, and first, second, and third-degree relatives, were recruited to the neuro-genetic clinic of Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. SMA cases and suspected carriers were referred to the genetic laboratory. Pregnant women underwent amniocentesis and chorionic villi sampling at 12–14 gestational weeks. RFLP-PCR and real-time PCR were performed for symptomatic and asymptomatic individuals (possible carriers), respectively. RFLP and real-time PCR were performed for amniotic fluid and chorionic villi samples.ResultsThe study enrolled 622 subjects from SMA-affected families, including 159 fetuses and 463 non-fetuses. Two samples were missing. A total of 268 individuals (43.2%) were healthy (wild type), 187 individuals (30.1%) were heterozygous for exon deletion of SMN1, and 143 individuals (23%) were homozygous for exon deletion of SMN1. Four individuals (0.6%) showed three copies of the SMN1 gene.ConclusionThe frequency of carriers with two SMN1 copies on a single chromosome (cis) was estimated at 2.9% (18/622), and the total rate of carriers was approximately 21.8%. Considering the high rate of SMA carriers in this study, genetic counseling and definitive prenatal diagnosis are of utmost importance for reducing the psychosocial burden of the SMA disease among Iranian families.

System Design and Development of a Novel, Unique Neuro Physical Medical Treatment Method for Spinal Muscular Atrophy and Similar Neurological Muscle Diseases.

The project is entirely original to the author. It proposes the theory of a method under development aimed at treating SMA and other related neurological muscle disorders The study will utilize a 14-channel EEG device to analyze brain data. The brain signals recorded by this device will be transmitted to the patient's muscles, potentially restoring functions lost in SMA patients. These functions include coughing, swallowing, breathing, chewing, walking, and movements of the hands, arms, and other muscles. By using this EEG device, brain signals can be visualized as waves, and its specialized software allows users to manipulate objects on a computer screen with thought alone. The system also simulates facial movements and expressions on-screen

An interpretable data-driven prediction model to anticipate scoliosis in spinal muscular atrophy in the era of (gene-) therapies

5q-spinal muscular atrophy (SMA) is a neuromuscular disorder (NMD) that has become one of the first 5% treatable rare diseases. The efficacy of new SMA therapies is creating a dynamic SMA patient landscape, where disease progression and scoliosis development play a central role, however, remain difficult to anticipate. New approaches to anticipate disease progression and associated sequelae will be needed to continuously provide these patients the best standard of care. Here we developed an interpretable machine learning (ML) model that can function as an assistive tool in the anticipation of SMA-associated scoliosis based on disease progression markers. We collected longitudinal data from 86 genetically confirmed SMA patients. We selected six features routinely assessed over time to train a random forest classifier. The model achieved a mean accuracy of 0.77 (SD 0.2) and an average ROC AUC of 0.85 (SD 0.17). For class 1 ‘scoliosis’ the average precision was 0.84 (SD 0.11), recall 0.89 (SD 0.22), F1-score of 0.85 (SD 0.17), respectively. Our trained model could predict scoliosis using selected disease progression markers and was consistent with the radiological measurements. During post validation, the model could predict scoliosis in patients who were unseen during training. We also demonstrate that rare disease data sets can be wrangled to build predictive ML models. Interpretable ML models can function as assistive tools in a changing disease landscape and have the potential to democratize expertise that is otherwise clustered at specialized centers.

Cognitive function in SMA patients with 2 or 3 SMN2 copies treated with SMN-modifying or gene addition therapy during the first year of life

BackgroundSpinal muscular atrophy (SMA) is a neuromuscular disease, causing progressive muscle weakness due to loss of lower motoneurons. Since 2017, three therapies, two modifying gene transcription and one adding the defective gene, have been approved with comparable efficacy on motor outcome. Data on cognitive outcomes of treated SMA type 1 patients is limited. The aim of this study was to evaluate cognitive function in symptomatic and presymptomatic SMA type 1 patients with two or three SMN2 copies who received SMN-modifying or gene-addition therapy in the first year of life. MethodsCognitive testing was performed in 20 patients, including 19 symptomatic SMA type 1 patients with up to three SMN2 copies and 1 pre-symptomatically treated patient. Children were tested using Bayley Scales of Infant Development (BSID-III) at the age of 2 or 3 years or the Wechsler Preschool and Primary Scale of Intelligence (WPSII-IV) at the of age of 5 years. Results11/20 patients showed subnormal cognitive development. Boys had significantly lower cognitive scores. Patients requiring assisted ventilation or feeding support were more likely to have cognitive deficits. Achieving more motor milestones was associated with a better cognitive outcome. ConclusionTreated patients with SMA type 1 have heterogeneous cognitive function with 55 % of patients showing deficits. Risk factors for cognitive impairment in our cohort were male gender and need for assisted ventilation or feeding support. Therefore, cognitive assessment should be included in the standard of care to allow early identification of deficits and potential therapeutic interventions.

Considerations for Treatment in Clinical Care of Spinal Muscular Atrophy Patients.

Spinal Muscular Atrophy is a neurodegenerative disease which can lead to muscle weakness, paralysis, and in some cases death. There are many factors that contribute to the severity of symptoms and those factors can be used to determine the best course of treatment for the patients. We looked through published literature to create a set of considerations for treatment in patients with Spinal Muscular Atrophy including age, type, SMN2 copies, and any familial considerations. This can serve as a guide for what to consider in the treatment of SMA patients clinically.

Respiratory function in adult patients with spinal muscular atrophy treated with nusinersen - a monocenter observational study.

Insufficiency of respiratory muscles is the most important reason for mortality in the natural history of SMA. Thus, improvement or stabilization of respiratory function by disease-modifying therapies (DMT) is a very important issue. We examined respiratory function using forced vital capacity (FVC) in 42 adult SMA patients (2 SMA type 1, 15 SMA type 2, 24 SMA type 3, 1 SMA type 4, median age 37 years, range 17-61 years) treated with nusinersen for a median of 22.1 months (range 2.1 to 46.7 months). Change in FVC was assessed using mixed effects linear regression models. Baseline FVC differed significantly between SMA type 1 (4.0, 8.0%), 2 (median 22.0%, IQR 18.0-44.0), 3 (median 81.0%, IQR 67.0-90.8) and, respectively, type 4 (84.0%) patients reflecting the heterogeneity of respiratory impairment based on the SMA type in adulthood (p < 0.0001). FVC remained stable during follow-up (mean -0.047, 95% CI -0.115 to 0.020, p = 0.17); however, subgroup analysis showed an increase in FVC of type 2 patients (mean 0.144, 95% CI 0.086 to 0.202, p < 0.0001) and a decrease in FVC of type 3/4 patients (-0.142, 95% CI -0.239 to -0.044, p = 0.005). The observed improvement in FVC in patients with SMA type 2 can be seen as a therapeutic response differing from the progressive decline typically seen in the spontaneous course. For SMA type 3/4 patients approaching normal spirometry at baseline, FVC may only be of limited use as an outcome parameter due to ceiling effects.

Motor unit number estimation via MScanFit MUNE in spinal muscular atrophy.

MScanFit MUNE (MScanFit) is a novel tool to derive motor unit number estimates (MUNEs) from compound muscle action potential (CMAP) scans. Few studies have explored its utility in 5q spinal muscular atrophy (SMA5q) patients, assessing only the abductor pollicis brevis (APB) muscle. We aimed to assess different distal muscles in pediatric and adult SMA5q patients, further evaluating clinical-electrophysiological correlations. We analyzed MScanFit parameters reflecting the extent of denervation (MUNE; N50) and parameters of collateral reinnervation in APB, abductor digiti minimi (ADM), and tibialis anterior (TA) muscles. SMA patients were clinically evaluated using standardized motor function clinical scales, including the Hammersmith Functional Motor Scale - Expanded and the Revised Upper Limb Module. A total of 23 SMA5q (9 SMA type 2 and 14 SMA type 3) and 12 age-matched healthy controls (HCs) were enrolled. SMA patients showed lower MUNE and N50 values and higher parameters of collateral sprouting in all muscles compared to HC (p < .001). SMA type 2 patients demonstrated lower MUNE and higher collateral reinnervation values in APB and TA compared to SMA type 3 (p < .05). Walker patients showed higher values of MUNE and N50, and lower parameters of reinnervation in all muscles compared to sitters (p < .05). MScanFit parameters showed strong correlations (Rho-values ranging from .72 to .83) with clinical measurements. MUNE values were abnormal in muscles that were not clinically affected. MScanFit parameters showed promise as an outcome measure. Further studies, particularly longitudinal ones, are needed to evaluate MScanFit in measuring response to treatments.

5qSMA: standardised retrospective natural history assessment in 268 patients with four copies of SMN2

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.

Non-ionizing measurement and quantification of bell-shaped chests in spinal muscular atrophy: a pilot study.

Spinal Muscular Atrophy (SMA) is manifested by deformation of the chest wall, including a bell-shaped chest. We determined the ability of a novel non-ionizing, non-volitional method to measure and quantify bell-shaped chests in SMA. A 3D depth camera and a chest x-ray (CXR) were used to capture chest images in 14 SMA patients and 28 controls. Both methods measure the distance between two points, but measurements performed by 3D analysis allow for the consideration of the curve of a surface (geodesic measurements), whereas the CXR allows solely for the determination of the shortest path between two points, with no regard for the surface (Euclidean measurements). The ratio of the upper to lower chest distances was quantified to distinguish chest shape in imaging by both the 3D depth camera and the CXR, and the ratios were compared between healthy and SMA patients. The mean 3D Euclidean ratio of distances measured by 3D imaging was 1.00 in the control group and 0.92 in the SMA group (p = 0.01), the latter indicative of a bell-shaped chest. This result repeated itself in the ratio of geodesic measurements (0.99 vs. 0.89, respectively, p = 0.03). The herein-described novel, noninvasive 3D method for measuring the upper and lower chest distances was shown to distinguish the bell-shaped chest configuration in patients with SMA from the chests of controls. This method bears several advantages over CXR and may be readily applicable in clinical settings that manage children with SMA.