Spinal Muscular Atrophy Research Articles

Common complications in spinal muscular atrophy (SMA) type 1 after nusinersen treatment

Background. Spinal muscular atrophy (SMA) is an inherited disease with progressive muscle weakness and atrophy. Despite the new treatments developed recently, primary and secondary effects of muscle weakness in patients with SMA cause mortality and morbidity. The aim of this study is to identify common problems in the follow-up of patients after new treatment modalities and to examine the difficulties in management of these problems. Methods. The study included 16 patients diagnosed with SMA type 1 according to clinical findings and genetic results between 2017 and 2022. The patients were divided into two groups as living and deceased, and complications were examined and compared between the groups. Results. The patients comprised 8 (50%) females and 8 (50%) males with a median age at diagnosis of 3 months. The patients had a history of gastrointestinal problems, orthopedic problems, infection and sepsis, and especially respiratory distress. Death occurred in 8 (50%) patients during follow-up (median age 38 months). Mortality was higher in patients who needed tracheostomy and had gastroesophageal reflux. The survival rate was better in patients who received more nusinersen treatment and had a higher CHOP-INTEND score. Conclusions. Despite new-generation treatments for SMA type 1, morbidity and mortality rates remain very high. As the survival rate in SMA type 1 increases, the incidence of complications similar to those frequently seen in SMA type 2 and type 3 patients also increases. The follow-up and treatment of patients with SMA should be undertaken by a multidisciplinary team.

Reverse Split Hand as a Neurophysiological Hallmark of Spinal Muscular Atrophy

Objective: Motor unit number estimation (MUNE) methods are crucial for estimating lower motor neuron loss in motor neuron diseases. The MScanFit MUNE (MScanFit) is a novel method that estimates MUNE values from compound motor action potential (CMAP) scans, demonstrating high sensitivity and reproducibility in detecting motor unit loss in amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). In this study, we aimed to characterize the pattern of motor unit loss in the hand intrinsic muscles of SMA patients compared to ALS patients and healthy controls (HC) using MScanFit MUNE. Methods: Patients diagnosed with ALS, adult SMA patients, and HC were prospectively enrolled. MScanFit examinations were performed on the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. To focus on the different patterns of motor neuron degeneration in the intrinsic hand muscles, the ratio of CMAP amplitude of APB to ADM (CMAP ratio) and the ratio of MUNE values of APB to those of the ADM muscle (MUNE ratio) were calculated. Results: The study included 46 ALS patients, 16 SMA patients, and 23 HC. MScanFit MUNE revealed distinct patterns of motor unit degeneration in SMA patients, notably more severe in the ADM than in the APB muscle, indicating a “reverse” split-hand phenomenon. Both CMAP and MUNE ratios demonstrated high diagnostic accuracy in distinguishing ALS from SMA, with the MUNE ratio performing better. Conclusions: MScanFit MUNE is a valuable tool for exploring distinct patterns of motor neuron degeneration in patients with different types of motor neuron diseases.

DeepRSMA: a cross-fusion based deep learning method for RNA-small molecule binding affinity prediction.

RNA is implicated in numerous aberrant cellular functions and disease progressions, highlighting the crucial importance of RNA-targeted drugs. To accelerate the discovery of such drugs, it is essential to develop an effective computational method for predicting RNA-small molecule affinity (RSMA). Recently, deep learning based computational methods have been promising due to their powerful nonlinear modeling ability. However, the leveraging of advanced deep learning methods to mine the diverse information of RNAs, small molecules and their interaction still remains a great challenge. In this study, we present DeepRSMA, an innovative cross-attention-based deep learning method for RSMA prediction. To effectively capture fine-grained features from RNA and small molecules, we developed nucleotide-level and atomic-level feature extraction modules for RNA and small molecules, respectively. Additionally, we incorporated both sequence and graph views into these modules to capture features from multiple perspectives. Moreover, a Transformer-based cross-fusion module is introduced to learn the general patterns of interactions between RNAs and small molecules. To achieve effective RSMA prediction, we integrated the RNA and small molecule representations from the feature extraction and cross-fusion modules. Our results show that DeepRSMA outperforms baseline methods in multiple test settings. The interpretability analysis and the case study on spinal muscular atrophy (SMA) demonstrate that DeepRSMA has the potential to guide RNA-targeted drug design. The codes and data are publicly available at https://github.com/Hhhzj-7/DeepRSMA. Supplementary data are available at Bioinformatics online.

Managing the challenges of paying for gene therapy: strategies for market action and policy reform in the United States.

Gene therapies delivered through a single administration have revolutionized treatment possibilities for many patients living with serious or fatal conditions such as spinal muscular atrophy, hemophilia and sickle cell disease. However, shadowing the excitement about the transformational potential of many gene therapies has been widespread concern about the combination of uncertainty in the durability of their benefits over the long term and the short-term financial shock of high prices. As the healthcare payment ecosystem prepares for the growing number of gene therapies entering the market, three key interconnected challenges must be addressed: determining a fair price, managing clinical uncertainty and managing short-term budget impacts. This paper identifies specific policy reforms and market-based tools to help the US health system address these challenges to achieve more equitable and affordable access for patients to the growing number of gene therapies expected to be approved in the coming years.

A Modular Genetic Approach to Newborn Screening from Spinal Muscular Atrophy to Sickle Cell Disease—Results from Six Years of Genetic Newborn Screening

Background/Objectives: Genetic newborn screening (NBS) has already entered the phase of common practice in many countries. In Germany, spinal muscular atrophy (SMA), severe combined immunodeficiency (SCID) and sickle cell disease (SCD) are currently a mandatory part of NBS. Here, we describe the experience of six years of genetic NBS including the prevalence of those three diseases in Germany. Methods: Samples and nucleic acids were extracted from dried blood spot cards, commonly used for NBS. A qPCR assay was used to detect disease-causing variants for SMA and SCD, and the detection of T-cell receptor excision circles (TRECs) was performed for SCID screening. Results: The results of the NBS of over 1 million newborns for SMA, approximately 770,000 for SCID and over 410,000 for SCD are discussed in detail. In these newborns, we have identified 121 cases of SMA, 15 cases of SCID and syndrome-based immunodeficiencies and 77 cases of SCD or β-thalassemia. Conclusions: The flexibility of multiplex qPCR is assessed as an effective tool for incorporating different molecular genetic markers for screening. The processing of dried blood spot (DBS) filter cards for molecular genetic assays and the assays are described in detail; turn-around times and cost estimations are included to give an insight into the processes and discuss further options for optimization. The identified cases are in the range expected for the total number of screened newborns, but present a more exact view on the actual prevalences for Germany.

CAGn Polymorphic Locus of Androgen Receptor (AR) Gene in Russian Infertile and Fertile Men

The androgen receptor (AR) is critical for mediating the effects of androgens. The polymorphic CAGn locus in exon 1 of the AR gene is associated with several diseases, including spinal and bulbar muscular atrophy (SBMA), prostate cancer, and male infertility. This study evaluated the CAGn locus in 9000 infertile Russian men and 286 fertile men (control group). The CAGn locus was analyzed using the amplified fragment length polymorphism method. In the infertile cohort, the number of CAG repeats ranged from 6 to 46, with a unimodal distribution. The number of CAG repeats in infertile and fertile men was 22.15 ± 0.93 and 22.02 ± 1.36, respectively. In infertile men, variants with 16 to 29 repeats were present in 97% of the alleles. A complete mutation (≥42 CAG repeats) was found in three patients, while three others had 39-41 repeats. The incidence of SBMA was 1:3000 infertile men. Significant differences (p < 0.05) were observed between infertile and fertile men in alleles with 21, 24 and 25 repeats. This study revealed certain differences in the CAGn polymorphic locus of the AR gene in Russian infertile and fertile men and determined the frequency of SBMA in infertile patients.

Comparative meta-analysis of transcriptomic studies in spinal muscular atrophy: comparison between tissues and mouse models.

Spinal Muscular Atrophy (SMA), a neuromuscular disorder that leads to weakness in the muscles due to degeneration of motor neurons. Mutations in the survival motor neuron 1 (SMN1) gene leads to the deficiency of SMN protein that causes SMA. The molecular alterations associated with SMA extends across the transcriptome and proteome. Although several studies have examined the transcriptomic profile of SMA, the difference in experimental settings across these studies highlight the need for a comparative meta-analysis to better understand these differences. We conducted a systematic comparative meta-analysis of publicly available gene expression data from six selected studies to elucidate variations in the transcriptomic landscape across different experimental conditions, including tissue types and mouse models. We used both microarray and RNA-seq datasets, retrieved from Gene Expression Omnibus (GEO) and ArrayExpress (AE). Methods included normalization, differential expression analysis, gene-set enrichment analysis (GSEA), network reconstruction and co-expression analysis. Differential expression analysis revealed varying numbers of differentially expressed genes ranging between zero and 1,655 across the selected studies. Notably, the Metallothionein gene Mt2 was common in several of the eight comparisons. This highlights its role in oxidative stress and detoxification. Additionally, genes such as Hspb1, St14 and Sult1a1 were among the top ten differentially expressed genes in more than one comparison. The Snrpa1 gene, involved in pre-mRNA splicing, was upregulated in the spinal cord and has a strong correlation with other differentially expressed genes from other comparisons in our network reconstruction analysis. Gene-set enrichment analysis identified significant GO terms such as contractile fibers and myosin complexes in more than one comparison which highlights its significant role in SMA. Our comparative meta-analysis identified only few genes and pathways that were consistently dysregulated in SMA across different tissues and experimental settings. Conversely, many genes and pathways appeared to play a tissue-specific role in SMA. In comparison with the original studies, reproducibility was rather weak.

Identification of Biochemical Determinants for Diagnosis and Prediction of Severity in 5q Spinal Muscular Atrophy Using 1H-Nuclear Magnetic Resonance Metabolic Profiling in Patient-Derived Biofluids

This study explores the potential of 1H-NMR spectroscopy-based metabolic profiling in various biofluids as a diagnostic and predictive modality to assess disease severity in individuals with 5q spinal muscular atrophy. A total of 213 biosamples (urine, plasma, and CSF) from 153 treatment-naïve patients with SMA across five German centers were analyzed using 1H-NMR spectroscopy. Prediction models were developed using machine learning algorithms which enabled the patients with SMA to be grouped according to disease severity. A quantitative enrichment analysis was employed to identify metabolic pathways associated with disease progression. The results demonstrate high sensitivity (84–91%) and specificity (91–94%) in distinguishing treatment-naïve patients with SMA from controls across all biofluids. The urinary and plasma profiles differentiated between early-onset (type I) and later-onset (type II/III) SMA with over 80% accuracy. Key metabolic differences involved alterations in energy and amino acid metabolism. This study suggests that 1H-NMR spectroscopy based metabolic profiling may be a promising, non-invasive tool to identify patients with SMA and for severity stratification, potentially complementing current diagnostic and prognostic strategies in SMA management.

Real-time measurement of radiation exposure in interventional radiologists during CT-guided intrathecal injections of nusinersen.

Some patients with spinal muscular atrophy and scoliosis require CT guidance during injections of nusinersen. The radiation applied to the operator in such procedures becomes an important issue in terms of staff health and safety. The aim of the study was to assess the operator's radiation exposure during CT-guided nusinersen injections in patients with spinal muscular atrophy and scoliosis. Consecutive 40 CT-guided nusinersen injections were analyzed in terms of operator's radiation exposure measured in real time. The median radiation dose measured under the physician's lead apron and patient dose in terms of DLP was 0.20 µSv and 31.90 mGy*cm respectively. The radiation doses were significantly higher (p = 0.047) in patients with spinal instrumentation. The results show that CT-guided nusinersen injection is a relatively safe procedure in terms of operator's radiation exposure. This can allow for interventional radiologists to perform more procedures without exceeding their annual dose limit.

Response to Letter to the Editor: Effect of Nusinersen on Respiratory and Bulbar Function in Children with Spinal Muscular Atrophy.

Response to Letter to the Editor: Effect of Nusinersen on Respiratory and Bulbar Function in Children with Spinal Muscular Atrophy.

SMN depletion impairs skeletal muscle formation and maturation in a mouse model of SMA.

Spinal muscular atrophy (SMA) is characterized by low levels of the ubiquitously expressed Survival Motor Neuron (SMN) protein, leading to progressive muscle weakness and atrophy. Skeletal muscle satellite cells play a crucial role in muscle fiber maintenance, repair, and remodelling. While the effects of SMN depletion in muscle are well documented, its precise role in satellite cell function remains largely unclear. Using the Smn2B/- mouse model, we investigated SMN-depleted satellite cell biology through single fiber culture studies. Myofibers from Smn2B/- mice were smaller in size, shorter in length, had reduced myonuclear domain size, and reduced sub-synaptic myonuclear clusters-all suggesting impaired muscle function and integrity. These changes were accompanied by a reduction in the number of myonuclei in myofibers from Smn2B/- mice across all disease stages examined. Although the number of satellite cells in myofibers was significantly reduced, those remaining retained their capacity for myogenic activation and proliferation. These findings support the idea that a dysregulated myogenic process could be occurring as early in muscle stem cells during muscle formation and maturation in SMA. Targeting those pathways could offer additional options for combinatorial therapies for SMA.

SMN2 gene copy number affects the incidence and prognosis of motor neuron diseases in Japan

BackgroundThe copy number status (CNS) of the survival motor neuron (SMN) gene may influence the risk and prognosis of amyotrophic lateral sclerosis (ALS) and lower motor neuron diseases (LMND) other than spinal muscular atrophy (SMA). However, previous studies of this association, mainly from Europe, have yielded controversial results, suggesting possible regional differences. Here, we investigated the effect of the SMN gene in Japanese patients with ALS and LMND.MethodsWe examined the SMN copy numbers and clinical histories of 487 Japanese patients with sporadic ALS (281 men; mean age at onset 61.5 years), 50 with adult LMND (50 men; mean age at onset 58.4 years) and 399 Japanese controls (171 men; mean age 62.2 years). Patients with pathogenic mutations in ALS-causing genes were excluded. SMN1 and SMN2 copy numbers were determined using the droplet digital polymerase chain reaction.ResultsThe frequency of a copy number of one for the SMN2 gene was higher in patients with ALS (38.0%) than in healthy controls (30.8%) (odds ratio (OR) = 1.37, 95% confidence interval (CI) = 1.04–1.82, p < 0.05). The SMN2 copy number affected the survival time of patients with ALS (median time: 0 copies, 34 months; 1 copy, 39 months; 2 copies, 44 months; 3 copies, 54 months; log-rank test, p < 0.05). Cox regression analysis revealed that the SMN2 copy number was associated with increased mortality (hazard ratio = 0.84, 95% CI = 0.72–0.98, p < 0.05). Also, null SMN2 cases were significantly more frequent in the LMND group (12.0%) than in the control group (4.8%) (OR = 2.73, 95% CI = 1.06–6.98, p < 0.05).ConclusionsOur findings suggest that SMN2 copy number reduction may adversely affect the onset and prognosis of MND, including ALS and LMND, in Japanese.

Comprehensive newborn screening for severe combined immunodeficiency, X-linked agammaglobulinemia, and spinal muscular atrophy: the Chinese experience.

Newborn screening (NBS) for severe combined immunodeficiency (SCID), X-linked agammaglobulinemia (XLA), and spinal muscular atrophy (SMA) enables early diagnosis and intervention, significantly improving patient outcomes. Advances in real-time polymerase chain reaction (PCR) technology have been instrumental in facilitating their inclusion in NBS programs. We employed multiplex real-time PCR to simultaneously detect T-cell receptor excision circles (TRECs), kappa-deleting recombination excision circles (KRECs), and the absence of the survival motor neuron (SMN) 1 gene in dried blood spots from 103,240 newborns in Zhejiang Province, China, between July 2021 and December 2022. Of all the samples, 122 were requested further evaluation. After flow cytometry evaluation and/or genetic diagnostics, we identified one patient with SCID, two patients with XLA, nine patients with SMA [one of whom also had Wiskott-Aldrich Syndrome (WAS)], and eight patients with other medical conditions. The positive predictive values (PPVs) of NBS for SCID, XLA, and SMA were 2.44%, 2.78%, and 100%, respectively. The estimated prevalence rates in the Chinese population were 1 in 103,240 for SCID, 1 in 51,620 for XLA, and 1 in 11,471 for SMA. This study represents the first large-scale screening in mainland China using a TREC/KREC/SMN1 multiplex assay, providing valuable epidemiological data. Our findings suggest that this multiplex assay is an effective screening method for SCID, XLA, and SMA, potentially supporting the universal implementation of NBS programs across China.

Potential biomarkers of the effectiveness of pathogenetic therapy of spinal muscular atrophy in adults

The review summarizes and systematizes data on the prognostic significance of various biomarkers in determining the effectiveness of pathogenetic therapy for spinal muscular atrophy. The review includes a clinical case of a patient with type 3 spinal muscular atrophy. The case illustrates that a decrease in the level of heavy chains of neurofilaments in the cerebrospinal fluid of the patient during the use of pathogenetic therapy with nusinersen positively correlated with an improvement in motor function, assessed by standard functional scales.

Type-1 spinal muscular atrophy cohort before and after disease-modifying therapies.

Spinal muscular atrophy (SMA-5q) is a neurodegenerative disease characterized by progressive muscle atrophy, hypotonia, and weakness, with SMA 1 presenting symptoms within the first 6 months of life. Disease-modifying therapies have been approved, with better outcomes with earlier treatment. To describe the safety and clinical efficacy of disease-modifying therapies based on SMN1 and SMN2 gene strategies concerning motor, respiratory, and bulbar function. Patients with SMA 1 were divided into 2 groups: those exclusively on nusinersen (group 1) and those transitioning to onasemnogene abeparvovec (OA) (group 2). Over 18 months, patients were assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) scale, developmental milestones, ventilation needs and duration, nutritional support needs, consistency of food, and signs of dysphagia. There were ten patients, divided between the groups; in group 1, the average age for starting nusinersen was 53.6 (12-115) months, and, in group 2, the age was 7 (1-12) months for nusinersen and 15.2 (10-19) months for OA. Our results indicate that 70% of patients reached some motor milestones, with group 1 increasing by 10.2 points on the CHOP-INTEND scale, while group 2 increased by 33 points. Additionally, 90% of the patients experienced no respiratory decline, and 30% maintained oral feeding. No serious adverse effects or deaths were recorded. Both groups showed improvement in motor function and stabilization of respiratory and bulbar function, with the difference between the groups possibly being related to the earlier treatment initiation. Thus, the present study provides valuable insights into the real-world safety and clinical efficacy of disease-modifying therapies for SMA 1 patients.

Patient-specific responses to SMN2 splice-modifying treatments in spinal muscular atrophy fibroblasts

The availability of three therapies for the neuromuscular disease spinal muscular atrophy (SMA) highlights the need to match patients to the optimal treatment. Two of these treatments (nusinersen and risdiplam) target splicing of SMN2, but treatment outcomes vary from patient to patient. An incomplete understanding of the complex interactions between SMA genetics, SMN protein and mRNA levels, and gene-targeting treatments, limits our ability to explain this variability and identify optimal treatment strategies for individual patients. To address this, we analyzed responses to nusinersen and risdiplam in 45 primary fibroblast cell lines. Pre-treatment SMN2-FL, SMN2Δ7 mRNA, and SMN protein levels were influenced by SMN2 copy number, age, and sex. After treatment, SMN and mRNA levels were more heterogeneous. In 43% of patients, response to both therapies was similar, but in 57% one treatment led to a significantly higher SMN increase than the other treatment. Younger age, higher SMN2 copy number, and higher SMN levels before treatment predicted better in vitro efficacy. These findings showcase patient-derived fibroblasts as a tool for identifying molecular predictors for personalized treatment.

The Relevance of Spinal Muscular Atrophy Biomarkers in the Treatment Era

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder that currently has an approved treatment for all forms of the disease. Previously, biomarkers were primarily used for diagnostic purposes, such as detecting the presence of the disease or determining a specific clinical type of SMA. Currently, with the availability of therapy, biomarkers have become more valuable due to their potential for prognostic, predictive, and pharmacodynamic applications. This review describes the most promising physiological, functional, imaging and molecular biomarkers for SMA, derived from different patients’ tissues. The review summarizes information about classical biomarkers that are already used in clinical practice as well as fresh findings on promising biomarkers that have been recently disclosed. It highlights the usefulness, limitations, and strengths of each potential biomarker, indicating the purposes for which each is best suited and when combining them may be most beneficial.

Hereditary Neuromuscular Disorders in Reproductive Medicine

Neuromuscular disorders (NMDs) encompass a broad range of hereditary and acquired conditions that affect motor units, significantly impacting patients’ quality of life and reproductive health. This narrative review aims to explore in detail the reproductive challenges associated with major hereditary NMDs, including Charcot–Marie–Tooth disease (CMT), dystrophinopathies, Myotonic Dystrophy (DM), Facioscapulohumeral Muscular Dystrophy (FSHD), Spinal Muscular Atrophy (SMA), Limb–Girdle Muscular Dystrophy (LGMD), and Amyotrophic Lateral Sclerosis (ALS). Specifically, it discusses the stages of diagnosis and genetic testing, recurrence risk estimation, options for preimplantation genetic testing (PGT) and prenatal diagnosis (PND), the reciprocal influence between pregnancy and disease, potential obstetric complications, and risks to the newborn.

Efficacy of Nusinersen Treatment in Type 1, 2, and 3 Spinal Muscular Atrophy: Real-World Data from a Single-Center Study

Background: Spinal muscular atrophy (SMA) is an inherited neuromuscular disease characterized by progressive muscle weakness and atrophy due to the absence of the survival motor neuron 1 (SMN1) gene. SMA is classified into types 0 through 4 based on the age of symptom onset and the severity of motor function decline. Recent advances in SMA treatment, including nusinersen, onasemnogene abeparvovec, and risdiplam, have significantly improved the prognosis of SMA patients. This study evaluated the safety and efficacy of nusinersen in pediatric patients with SMA types 1, 2, and 3 in a real-world clinical setting. Methods: This prospective observational single-center study assessed the treatment effects of nusinersen in 23 pediatric patients with genetically confirmed SMA over a 22-month observation period. All the participants received intrathecal loading doses of 12 mg of nusinersen on days 1, 14, 28, and 63, followed by maintenance doses every four months. Functional assessments were conducted using the CHOP-INTEND scale. Data were collected during routine patient visits, including clinical laboratory tests and vital sign parameters, and adverse events were recorded. The inclusion criteria were defined by the national reimbursement program for nusinersen treatment in Poland. Results: Initially, 37 patients ranging from 1 month old to 18 years old were included, but 23 were ultimately observed due to changes in treatment regimens or assessment scales. The patients showed significantly improved CHOP-INTEND scores over the 22-month period. At 6 months, the average increase was 4.2 points, continuing to 17.8 points at 22 months. By the end of the study, 100% of patients showed either stabilization or improvement, with significant clinical improvements observed in several patients. Nusinersen was generally well-tolerated, with post-lumbar puncture headache and lower back pain being the most common adverse events. Conclusions: Nusinersen treatment significantly enhances motor function in pediatric patients with SMA types 1, 2, and 3. This study demonstrates the importance of early and sustained treatment, with most patients showing the continuous improvement or stabilization of motor function. These findings support the use of nusinersen as an effective therapy for SMA; however, further research is needed to understand the long-term outcomes and optimize treatment strategies.

Computed tomography-based radiological gynecomastia in SBMA as an independent differential diagnostic biomarker: a retrospective study.

Spinal bulbar muscular atrophy (SBMA) and amyotrophic lateral sclerosis (ALS) are motor neuron disorders that demonstrate overlapping clinical features, especially in the early stage. Therefore, the aim of this study was to investigate the utility of chest tomography (CT) imaging in distinguishing between SBMA and ALS. This was a retrospective study reviewing CT images from patients with SBMA and sporadic ALS and those in the control group. The CT images were assessed to measure the diameter and morphology of glandular tissue associated with gynecomastia. We compared CT-measured gynecomastia between the SBMA, ALS, and control groups. Additionally, correlation analyses were performed between the quantitative measurements of gynecomastia obtained from CT scans and various clinical/laboratory parameter in the SBMA group. 15 chest CT images were collected from SBMA, 41 from ALS, and 29 from control group. No statistical differences were observed in BMI, functional scales, or age at the time of CT scans between the SBMA and ALS groups. Despite similar functional scales and age in both groups, the mean glandular tissue diameter of breast tissue observed in chest CT imaging differed significantly between SBMA, ALS, and controls: 32.22 ± 12.57mm, 15.91 ± 4.81mm, and 15.76 ± 7.26mm, respectively. This disparity allowed for the differentiation of SBMA from ALS and controls with statistical significance. Clinical gynecomastia was 80%, while radiological gynecomastia was 93.3% in SBMA. A significantly higher prevalence of diffuse glandular morphology pattern in SBMA (50%) was observed, contrasting with the predominance of nodular morphology in ALS and controls (9.1% and 20%). Correlative analysis between glandular tissue diameter and other clinical/laboratory parameters within the SBMA group showed no specific finding. CT-based radiological gynecomastia effectively differentiated SBMA from ALS. These findings support the usefulness of radiological gynecomastia as a potential differential diagnostic marker for SBMA, especially in the early stages.