Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013362 (dysarthria)
 3,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Kennedy's disease (spinal and bulbar muscular atrophy) is an X-linked form of motor neuron disease that affects adult men. The syndrome is characterized by progressive atrophy of the limb muscles, pelvic and shoulder girdles and dysphagia and dysarthria, and is caused by the degeneration of spinal and bulbar motor neurons. Kennedy's disease is caused by a trinucleotide repeat expansion of a CAG repeat in exon A of the androgen receptor gene, and is one of a group of neurological diseases caused by trinucleotide repeat expansions in different genes. The mutation in Kennedy's disease involves an increased number of glutamine residues in the amino-terminal domain of the receptor. Point mutations and deletions in the androgen receptor gene cause androgen insensitivity syndrome, however subjects with Kennedy's disease have normal virilization, although progressive gynaecomastia, testicular atrophy and infertility may occur. Androgen receptors are expressed widely in the normal brain, and in the anterior horn cells of the spinal cord; however, their role in neuronal tissue is not known, nor is it known how the androgen receptor gene mutation causes neuronal degeneration. Kennedy's disease is likely to be a 'gain of function' abnormality, so that the presence of the receptor with an increased number of glutamines is toxic to motor neurons. It is possible that the mutation alters interaction of the receptor with other neuronal transcription factors, or neuronotoxicity may occur because of a non-specific effect caused by the presence of a protein with a large homoglutamine domain. Studies of patients with Kennedy's disease have shown that expression of androgen receptor mRNA and protein in spinal cord may be decreased, as can be the affinity of the mutant receptor for androgen. In vitro studies have shown impaired transcription activation ability of the mutant androgen receptor. The age at onset of Kennedy's disease may correlate with the size of the CAG repeat, however there is a large degree of variability of age at onset between subjects with the same number of repeats. Further study of the effect of the Kennedy's disease mutation on androgen receptor function in motor neurons will allow us to increase our understanding of the pathogenesis of this disease.
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PMID:Spinal and bulbar muscular atrophy: androgen receptor dysfunction caused by a trinucleotide repeat expansion. 886 71

A 71-year-old man developed clinical signs of Kennedy disease including dysarthria, dysphagia, palatal and oral mandibular fasciculations, lower-extremity weakness, gynecomastia, and testicular atrophy. Electrophysiologic studies showed sensory axonal polyneuropathy and chronic neurogenic changes of large-motor unit action potentials with decreased recruitment. Genetic analysis showed a normal 17-CAG repeat sequence. Laboratory studies showed an increased estrogen level of 180 to 220 pg/mL, probably related to his alcoholic fatty liver disease. Splenomegaly was present by ultrasound. The increased level of estrogen adversely affected estrogen-sensitive cells in breast, testicular, neuronal, and muscle cells, leading to the clinical phenotype.
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PMID:Hyperestrogenemia simulating kennedy disease. 1809 Jun 81