A very late-onset form of SMA-LED

Spinal muscular atrophy with lower extremity dominance (SMA-LED) is an ultra-rare distal spinal muscular atrophy initially described in children. Two distinct genes, DYNC1H1 and BICD2, cause SMA-LED1 and SMA-LED2 respectively. Australian clinicians report a highly original case due to the very late onset of the disease:

  • the patient had been suffering from a waddling gait for several years but the disorders became markedly worse from the age of 80 years;
  • amyotrophic lateral sclerosis was suspected for a while, but then rejected because of the slow evolution of the symptoms;
  • a genetic study using next-generation sequencing (NGS) identified a mutation in the BICD2 gene.

This observation confirms that the phenotypic range of SMA-LED extends beyond the paediatric population.


Late adult-onset spinal muscular atrophy with lower extremity predominance (SMALED). Aziz I, Davis M, Liang C. BMJ Case Rep. 2022 Mar 30;15(3):e248297.