Spinal Muscular Atrophy in Adult Neurology Services in India

Area of Science:

• Neurology
• Genetics
• Rare Diseases

Background:

• Spinal muscular atrophy (SMA) research predominantly focuses on pediatric cases, with limited data on adult populations, especially in low- and middle-income countries (LMICs).
• Adult SMA diagnosis is often delayed or missed due to overlapping symptoms with other neuromuscular disorders.

Purpose of the Study:

• To investigate the diagnostic challenges and clinical characteristics of adult spinal muscular atrophy (SMA) in northern India.
• To evaluate the utility of a genetics-first approach for diagnosing adult SMA in a resource-limited setting.

Main Methods:

• Prospective recruitment of suspected adult SMA patients (≥12 years) into a neuromuscular disease cohort.
• Utilized phenotyping, creatine kinase levels, electrophysiology, and genetic testing for diagnosis.
• Included 40 genetically confirmed adult SMA patients.

Main Results:

• The commonest presentation was proximal lower-limb weakness (82.5%).
• A significant proportion (45%) were initially misdiagnosed with conditions like muscular dystrophy or congenital myopathy.
• Three patients initiated treatment with risdiplam.

Conclusions:

• Adult SMA presents diagnostic challenges, underscoring the need for a genetics-first diagnostic strategy.
• Early genetic confirmation is vital to shorten diagnostic delays, reduce misclassification, and facilitate access to disease-modifying therapies in LMICs.