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).