Familial bulbo-spinal muscular atrophy associated with testicular atrophy and sensory neuropathy (Kennedy-Alter-Sung syndrome). Autopsy case report of two brothers.

Autopsy cases of two brothers with bulbo-spinal muscular atrophy associated with gynecomastia, testicular atrophy and sensory neuropathy are reported. The disease started with finger tremor, proximal muscle weakness and facial muscle twitching at the second and fourth decades, accompanied by bulbar signs and glove-stocking type sensory disturbance. Systemic neurogenic patterns and diminished sensory nerve action potential amplitudes were recorded by electrophysiological studies. A marked loss of myelinated fibers was noticed upon sural nerve biopsy. Gonadal hormone values were normal, except for elevated urinary estrogen. Postmortem examinations revealed a remarkable degeneration of the facial and hypoglossal nuclei, and the spinal cord motoneurons. The skeletal muscles and the tongue showed neurogenic muscular atrophy with fatty replacement. Testicular atrophy was prominent showing hyalinized seminiferous tubuli with nodular and diffuse Leydig cell hyperplasia, containing estrogen immunoreactive substance. These clinical and histological features seemed to be highly compatible with those of Kennedy-Alter-Sung type bulbo-spinal muscular atrophy. The involvement of sensory peripheral nerves, however, was a distinct feature of this family.