Spinal Muscular Atrophy (SMA)

Recently, individuals living with Spinal Muscular Atrophy (SMA) and their families have appealed to the Prime Minister of India for urgent intervention to ensure nationwide access to Risdiplam, a key drug used in the management of the disease. They have sought its inclusion and wider availability under the National Policy for Rare Diseases (NPRD) to make treatment more affordable and accessible.

What is Spinal Muscular Atrophy (SMA)?

Spinal Muscular Atrophy is a rare, inherited, and progressive neuromuscular disorder that affects the body's ability to control voluntary muscle movement. The disease causes gradual weakening and wasting of muscles, leading to severe physical disability and, in some cases, life-threatening complications.

It primarily affects motor neurons, which are specialized nerve cells located in the spinal cord and brainstem that control muscle movement. As these neurons degenerate and die, muscles receive fewer signals from the nervous system, resulting in progressive muscle weakness.

Cause of Spinal Muscular Atrophy

The majority of SMA cases are caused by mutations in the Survival Motor Neuron 1 (SMN1) gene, located on Chromosome 5. This gene is responsible for producing the SMN protein, which is essential for the survival and proper functioning of motor neurons.

When the gene is defective or absent, the body cannot produce sufficient quantities of the SMN protein. As a result, motor neurons gradually deteriorate, leading to muscle weakness and loss of movement.

Types of Spinal Muscular Atrophy

Healthcare professionals classify SMA into five major types—Type 0, Type 1, Type 2, Type 3, and Type 4. The classification is based on the age at which symptoms first appear, as well as the severity of the condition and expected life expectancy.

Type 0 is the most severe form and begins before birth, whereas Type 1 appears during infancy and is associated with significant motor impairment. Types 2 and 3 generally appear during childhood and vary in severity. Type 4 is the mildest form and usually develops during adulthood.

Symptoms of SMA

The symptoms of Spinal Muscular Atrophy can range from mild to severe depending on the type of the disease. The most common feature is progressive muscle weakness, particularly in muscles located closer to the centre of the body, such as those of the shoulders, hips, thighs, and upper arms.

Affected individuals may experience difficulty in sitting, standing, walking, swallowing, or breathing. As the disease progresses, muscle wasting becomes more pronounced, reducing mobility and independence.

Treatment and Management

At present, there is no permanent cure for Spinal Muscular Atrophy. Treatment primarily focuses on slowing disease progression, managing symptoms, improving quality of life, and preventing complications.

One of the important medicines used in treatment is Risdiplam, which helps increase the production of the SMN protein. Other supportive measures include physiotherapy, respiratory care, nutritional support, and rehabilitation services.

National Policy for Rare Diseases (NPRD)

The issue has gained importance in the context of the National Policy for Rare Diseases, which aims to improve diagnosis, treatment, and support for patients suffering from rare diseases in India. Since SMA treatment is often extremely expensive, patients and advocacy groups are seeking wider access to affordable generic medicines through government support mechanisms.

Significance for Public Health

Although SMA is classified as a rare disease, it poses significant challenges due to the high cost of treatment and the lifelong care required by patients. Improving access to medicines, strengthening rare disease registries, and expanding financial assistance can help reduce the burden on affected families and improve health outcomes.

Conclusion

Spinal Muscular Atrophy is a severe genetic disorder that progressively weakens muscles by damaging motor neurons. While there is currently no cure, advances in therapies such as Risdiplam offer hope for better disease management. Ensuring affordable access to treatment under the National Policy for Rare Diseases remains crucial for improving the lives of patients and their families