What is X-linked spinobulbar muscular atrophy (SBMA) (Kennedy disease)?

Updated: Apr 28, 2014
  • Author: Hidehiro Takei, MD; Chief Editor: Adekunle M Adesina, MD, PhD  more...
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Answer

Answer

First described in 1968 by Kennedy et al, [4] X-linked SBMA is an adult-onset, X-linked recessive trinucleotide, polyglutamine disorder that is caused by expansion of a polymorphic CAG tandem-repeat in exon 1 of the androgen-receptor gene on chromosome Xq11-12. [5]

This disorder is characterized by slowly progressive weakness of bulbar and limb muscles, associated with endocrinologic disturbances (androgen insensitivity). Because of X-linked transmission, this disorder almost exclusively affects males but is transmitted by female carriers.


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