Journal of Neurology and Neurorehabilitation Research

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Perspective - Journal of Neurology and Neurorehabilitation Research (2024) Volume 9, Issue 1

Navigating life with spinal muscular atrophy: Diagnosis, care, and emerging therapies

Mike Mignan *

Department of Pediatrics, University of Melbourne, Australia

*Corresponding Author:
Mike Mignan
Department of Pediatrics, University of Melbourne, Australia
E-mail: mignan@mibrn.aus

Received: 27-Dec-2023, Manuscript No. JNNR-24-137398; Editor assigned: 29-Dec-2023, PreQC No. JNNR-24-137398(PQ); Reviewed: 12-Jan-2024, QC No. JNNR-24-137398; Revised: 17-Jan-2024, Manuscript No. JNNR-24-137398(R); Published: 24-Jan-2024, DOI: 10.35841/aajnnr-9.1.185

Citation: : Mignan M. Navigating life with spinal muscular atrophy: Diagnosis, care, and emerging therapies. J Neurol Neurorehab Res.2024;9(1):185

Introduction

Spinal Muscular Atrophy (SMA) is a genetic disorder characterized by the loss of motor neurons in the spinal cord and brainstem, leading to progressive muscle weakness and atrophy. It is one of the most common genetic causes of infant mortality. Understanding the pathophysiology, symptoms, diagnosis, causes, treatment, and living with SMA is crucial for comprehending the impact of this debilitating disease [1].

SMA is caused by mutations in the SMN1 (Survival Motor Neuron 1) gene, which is responsible for producing the SMN protein. This protein is critical for the survival and function of motor neurons, which are the nerve cells that control voluntary muscle movements. The absence or deficiency of the SMN protein leads to the degeneration of motor neurons, causing muscle weakness and atrophy [2].

In addition to the SMN1 gene, humans have a nearly identical gene called SMN2. However, due to a splicing error, the SMN2 gene produces a much smaller amount of functional SMN protein. The number of SMN2 copies can influence the severity of SMA; individuals with more copies of SMN2 generally have a milder form of the disease because they produce more SMN protein [3].

SMA is classified into several types based on the age of onset and the severity of symptoms. These types range from Type 0, the most severe, to Type 4, the mildest. SMA Type 0 (Prenatal Onset): Symptoms are evident before birth. Severe muscle weakness and joint contractures. Respiratory failure at birth or shortly thereafter. Life expectancy is typically a few months [4].

SMA Type 1 (Werdnig-Hoffmann Disease): Symptoms appear before 6 months of age. Severe muscle weakness, poor muscle tone (floppiness), and difficulty breathing and swallowing. Inability to sit unsupported. Life expectancy without intervention is typically less than 2 years [5].

SMA Type 2 (Intermediate SMA): Symptoms appear between 6 and 18 months of age. Moderate to severe muscle weakness, primarily affecting the legs more than the arms. Ability to sit unsupported but not stand or walk independently. Life expectancy varies, but many live into adolescence or adulthood with proper care [6].

SMA Type 3 (Kugelberg-Welander Disease): Symptoms appear after 18 months of age. Mild to moderate muscle weakness, affecting the legs more than the arms. Ability to stand and walk independently, although mobility may decline over time. Normal life expectancy with proper management [7].

SMA is an autosomal recessive genetic disorder, meaning an individual must inherit two mutated copies of the SMN1 gene (one from each parent) to develop the disease. Carrier parents, who have one normal and one mutated copy of the gene, typically do not show symptoms but can pass the mutation to their children [8].

While there is no cure for SMA, recent advances have led to the development of therapies that can significantly improve outcomes. Treatment focuses on managing symptoms, slowing disease progression, and enhancing quality of life. Key treatments include: Zolgensma: An FDA-approved gene therapy that delivers a functional copy of the SMN1 gene, allowing the production of the SMN protein. It is administered as a one-time intravenous infusion, primarily used for SMA Type 1 [

SMN2 Splicing Modifiers: Spinraza (Nusinersen): An FDA-approved antisense oligonucleotide that modifies the splicing of the SMN2 gene, increasing the production of functional SMN protein. It is administered via intrathecal injection (into the spinal fluid) and is used for all types of SMA. Evrysdi (Risdiplam): An FDA-approved oral medication that also modifies SMN2 splicing to increase SMN protein production. It can be used for all types of SMA and is particularly beneficial for patients who cannot undergo spinal injections [10].

Conclusion

Spinal Muscular Atrophy is a severe genetic disorder that affects motor neurons, leading to progressive muscle weakness and atrophy. While there is no cure, significant advances in treatment have improved the prognosis and quality of life for individuals with SMA. A comprehensive approach to care, including gene therapy, SMN2 splicing modifiers, and supportive therapies, can help manage symptoms and slow disease progression. Ongoing research holds promise for more effective treatments and a deeper understanding of this challenging condition. Through continued efforts in scientific research, patient care, and advocacy, the outlook for those living with SMA continues to improve.

References

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