A non-Kennedy SBMA linked to the UBA1 gene

A new form of bulbospinal muscular atrophy has just been described by Iranian clinicians in 4 patients: it is an SBMA linked to the UBA1 gene.

  • It is therefore distinct from Kennedy’s disease, which is an SBMA linked to the AR gene (the authors speak of non-Kennedy SBMA).
  • The UBA1 gene is located on chromosome X and is involved in the proteasome/ubiquitin system.
  • The UBA1 gene is also responsible for an X-linked form of SMA, XL-SMA, which however starts earlier than non-Kennedy SBMA (onset in childhood and death before the age of two for XL-SMA versus onset in adulthood and normal life expectancy for non-Kennedy SBMA).


Identification of UBA1 as the causative gene of an X-linked non-Kennedy spinal-bulbar muscular atrophy. Khani M, Nafissi S, Shamshiri H et al. Eur J Neurol. 2022 Aug 23.