Spinal and bulbar muscular atrophy (SBMA) (a.k.a. Kennedy disease) is the only polyQ disease inherited in a sex-limited pattern, having a prevalence of ~1 per 300,000 males. It is characterized by late-onset, progressive degeneration of lower motor neurons of the spinal cord and in the bulbar region of the brain stem , as well as sensory neurons in the dorsal root ganglia. The disease is caused by a polymorphic CAG repeat expansion in the first exon of the AR gene coding region. Affected patients exhibit 37-70 repeats, while unaffected ones have 5-34 repeats , and, similarly to other polyQ diseases, there is a correlation between disease repeat length and disease severity. There is no treatment available yet to alter the course of SBMA.