X-linked spinobulbar muscular atrophy (SBMA) is a rare, neurodegenerative disorders caused
by an abnormal expansion of CAG repeats in the first exon of the gene encoding the androgen
receptor (AR) gene, located on chromosome Xq11-12. It is characterized by adult-onset, slowly
progressive muscle weakness and atrophy of the bulbar, facial and limb muscles. SBMA also
shows a sensory involvement and signs of androgen insensitivity including gynecomastia,
testicular atrophy and erectile dysfunction. AR, a disease-causing protein of SBMA, functions as a
ligand-dependent transcriptional factor. The native function and sequential processing of AR play an
important role in the pathogenesis and developing therapeutic interventions of SBMA. This article
reviews the clinical and electrophysiological characteristics of SBMA and provides the update of
therapeutic trials in SBMA.



KEYWORDS
Spinobulbar muscular
atrophy,
Kennedy disease,
Motor neuron disease,
Androgen