Analysis of spinal muscular atrophy patients from the spinal muscular atrophy and muscular dystrophy registry of Pakistan

Background: Spinal Muscular Atrophy (SMA) leads to motor neuron loss, with progressive muscle weakness and wasting. Nationwide registries for neuromuscular diseases are pivotal for assessing epidemiology, preparing for clinical trials, and for adopting standardized management guidelines. Objectives: This paper aims to present data gathered during the establishment of Pakistan's inaugural registry for genetically confirmed SMA cases. Methods: In this retrospective study, 215 participants with genetically confirmed SMA were recruited. Telephonic interviews were conducted to collect data for the Muscular Disease Registry of Pakistan that was analyzed using STATA version 17.0. Results: SMA type 1 was the most common type (71.2%, n = 153). Amongst patients who were tested for survival motor neuron (SMN2) copies, the majority (84.4%, n = 168) had two SMN2 copies. SMA types were significantly associated with the ability to sit (p < 0.001) and walk (p < 0.001), and usage of a wheelchair (p = 0.0054). SMN2 copy numbers were significantly associated with the ability to sit (p = 0.020) and walk (p = 0.031). Conclusions: This study highlights the high prevalence of SMA genotypes and phenotypes associated with severe disease in our population. Our findings reiterate the challenging prognosis for Pakistani children with SMA and underscore the necessity of the development of nationwide newborn screening programs and making treatments available.