Tuesday 14 April 2009
Bulbospinal atrophy (Kennedy syndrome) is a X-linked adult-onset disease, characterized by distal limb amyotrophy and bulbar signs such as atrophy and fasciculations of the tongue and dysphagia.
Affected individuals manifest androgen insensitivity with gynecomastia, testicular atrophy, and oligospermia.
On microscopic examination, there is degeneration of lower motor neurons in the spinal cord and brainstem.
The gene defect is expansion of a CAG/polyglutamine repeat in the androgen receptor (40 to 60 for affected individuals as opposed to 11 to 33 for the normal allele); nuclear inclusions containing aggregated androgen receptor can be found.
There is no anticipation with this disorder, and there is not a strong correlation between the size of the expansion and severity of clinical phenotype.
neurodegenerative diseases affecting motor neurons