Factors modifying the course of spinal muscular atrophy 5q

Abstract

Proximal spinal muscular atrophy 5q (SMA 5q) is a severe autosomal recessive neuromuscular disease characterized by progressive symptoms of flaccid paralysis and muscular atrophy due to degeneration of α-motor neurons of the anterior horns of the spinal cord. To date, the main modifying factor of spinal muscular atrophy is considered to be the number of copies of the SMN2 gene. However, a sufficient number of other genetic and non-genetic modifiers of the course of SMA have been described.Advanced neonatal screening, which started in the Russian Federation in 2023, allows detecting SMA 5q before the onset of clinical manifestations. However, to start therapy and select the right drug, it is important to know not only the main modifying factor (the number of copies of SMN2), but also other genetic causes that may affect the age of the disease manifestation or the effectiveness of therapy.