title: Clinical Characteristics and Genotype-Phenotype Correlation of Korean Patients with Spinal and Bulbar Muscular Atrophy.
abstract: OBJECTIVE
  Spinal and bulbar muscular atrophy (SBMA) is an X-linked motor neuron disease characterized by proximal muscle weakness, muscle atrophy, and fas-ciculation. Although SBMA is not uncommon in Korea, there is only one study reporting clinical characteristics and genotype-phenotype correlation in Korean patients.
  
  
  METHODS
  In this study, age at the onset of symptoms, the score of severity assessed by impairment of activities of daily living milestones, and rate of disease progression, and their correlations with the number of CAG repeats in the androgen receptor (AR) gene, as well as possible correlations among clinical characteristics, were analyzed in 40 SBMA patients.
  
  
  RESULTS
  The median ages at onset and at diagnosis were 44.5 and 52.5 years, respectively, and median interval between onset and diagnosis and median rate of disease progression were 5.0 years and 0.23 score/year, respectively. The median number of CAG repeats in the AR gene was 44 and the number of CAG repeats showed a significant inverse correlation with the age at onset of symptoms (r=-0.407, p=0.009). In addition, patients with early symptom onset had slower rate of disease progression.
  
  
  CONCLUSIONS
  As a report with the largest and recent Korean cohort, this study demonstrates clinical features of Korean patients with SBMA and reaffirms the inverse correlation between the age at disease onset and the number of CAG repeats. Interestingly, this study shows a possibility that the rate of disease progression may be influenced by the age at onset of symptoms.
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ju Sun
authors.initials: JS
authors.lastname: Song
authors.affiliation: Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Ah
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. juhongm@gmail.com.
authors.forename: Ju-Hong
authors.initials: JH
authors.lastname: Min
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. changski@skku.edu.
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Ki
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Duk Hyun
authors.initials: DH
authors.lastname: Sung
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Byoung Joon
authors.initials: BJ
authors.lastname: Kim
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D017668:Age of Onset; D044466:Asian People / Q000235:genetics*; D055534:Bulbo-Spinal Atrophy, X-Linked / Q000235:genetics / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005808:Genes, Recessive; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000503:physiopathology*; D009134:Muscular Atrophy, Spinal; D020966:Muscular Disorders, Atrophic / Q000235:genetics*; D010641:Phenotype; D011944:Receptors, Androgen / Q000235:genetics*; D056910:Republic of Korea; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D011944:Receptors, Androgen
keywords: Androgen receptor gene; CAG repeats; genotype-phenotype correlation; spinal and bulbar muscular atrophy