Abstract
Background
Spinal muscular atrophy (SMA) is a recessively inherited autosomal neuromuscular disorder that is associated with deletions or disease-causing variants in the survival motor neuron 1 (SMN1) gene. Delayed diagnosis of SMA remains a common issue worldwide, particularly in regions with unequal medical resources.Case presentation
Patient 1 was a 21-year-old man who had experienced limb weakness and muscle atrophy for 20 years. At the age of 6, he underwent genetic testing and was diagnosed with SMA type II. Patient 2 was a 26-year-old man who had been complaining of progressive limb weakness for 11 years and muscle atrophy for 5 years. When he was 20 years old, he experienced muscle atrophy of both legs and was diagnosed with SMA type III after genetic testing. Patient 3 was a 40-year-old man who presented with slowly progressive lower limb weakness since the age of 15. He was misdiagnosed with Duchenne muscular dystrophy in age 20. He was referred to our clinic at the age 40 and was ultimately confirmed to have SMA after genetic testing. Patients 4 and 5 were sisters, who complained of lower limb weakness and were recently diagnosed with SMA.Conclusions
This case series highlights the current status and possible reasons for delayed diagnosis and delayed initiation of treatment for SMA, including limited awareness of SMA, low accessibility of genetic testing, and uneven distribution of medical resources.